I am getting the Run time exception in my application and I have tried a lot to sort it out but couldn't do it.
Here is the code where I am getting the error:
public class FirstDemo extends ListActivity
{
private ListView Lv02;
private String Lv_Arr02[]={ "darshan", "sunil", "viral", "jaimin", "aashish", "jaydev", "bhavesh"};
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.mylistview); ( Here I am getting the Exception )
Lv02=(ListView) findViewById(R.id.lstvw_mylist);
}
}
My Stack Trace is as under:
12-30 11:21:09.525: ERROR/AndroidRuntime(517): FATAL EXCEPTION: main
12-30 11:21:09.525: ERROR/AndroidRuntime(517): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.mytabhostdemo/com.android.mytabhostdemo.FirstDemo}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:651)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.widget.TabHost.setCurrentTab(TabHost.java:323)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:129)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:453)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.view.View.performClick(View.java:2408)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.view.View$PerformClick.run(View.java:8816)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.os.Handler.handleCallback(Handler.java:587)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.os.Handler.dispatchMessage(Handler.java:92)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.os.Looper.loop(Looper.java:123)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.ActivityThread.main(ActivityThread.java:4627)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at java.lang.reflect.Method.invokeNative(Native Method)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at java.lang.reflect.Method.invoke(Method.java:521)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at dalvik.system.NativeStart.main(Native Method)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.ListActivity.onContentChanged(ListActivity.java:245)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:201)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.Activity.setContentView(Activity.java:1647)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at com.android.mytabhostdemo.FirstDemo.onCreate(FirstDemo.java:17) (Here I think)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
12-30 11:21:09.525: ERROR/AndroidRuntime(517): ... 18 more
It would be great if anybody could help me.
Thanks,
david
In your XML file your top element must be a ListView since you derive from ListActivity.
example:
<ListView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#android:id/list">
</ListView>
When deriving from specific activities Android expects there to be a specific definition in your layout XML file with a predefined ID.
If you post your XML we can fix it for you.
Related
We tried integrating HelpStack by following steps given on GitHub, but we kept getting the following errors:
04-03 13:54:22.054 4638-4638/com.playerline.android E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.playerline.android/com.tenmiles.helpstack.activities.HomeActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4448)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.tenmiles.helpstack.activities.HSActivityParent.onCreate(HSActivityParent.java:48)
at com.tenmiles.helpstack.activities.HomeActivity.onCreate(HomeActivity.java:46)
at android.app.Activity.performCreate(Activity.java:4465)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4448)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
I'm guessing it has something to do with the App Theme, which in our case is is Theme.AppCompat.NoActionBar.
I am getting an "Error inflating class fragment". Is it due to an error in my xml file? I have a feeling it may have something to do with the namespaces I'm using, but I'm not sure...
Here's the logcat:
12-30 11:02:41.525: I/dalvikvm(8714): Could not find method
com.example.gameexpensetracker.Chart_screen_activity.getFragmentManager, referenced from method com.example.gameexpensetracker.Chart_screen_activity.pieGraphData
12-30 11:02:41.525: W/dalvikvm(8714): VFY: unable to resolve virtual method 5181: Lcom/example/gameexpensetracker/Chart_screen_activity;.getFragmentManager ()Landroid/app/FragmentManager;
12-30 11:02:41.535: D/dalvikvm(8714): VFY: replacing opcode 0x6e at 0x0204
12-30 11:02:41.535: D/dalvikvm(8714): VFY: dead code 0x0207-02c9 in Lcom/example/gameexpensetracker/Chart_screen_activity;.pieGraphData ()V
12-30 11:02:41.555: D/AndroidRuntime(8714): Shutting down VM
12-30 11:02:41.555: W/dalvikvm(8714): threadid=1: thread exiting with uncaught exception (group=0x40015560)
12-30 11:02:41.565: E/AndroidRuntime(8714): FATAL EXCEPTION: main
12-30 11:02:41.565: E/AndroidRuntime(8714): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.gameexpensetracker/com.example.gameexpensetracker.Chart_screen_activity}: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.os.Handler.dispatchMessage(Handler.java:99)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.os.Looper.loop(Looper.java:123)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread.main(ActivityThread.java:3683)
12-30 11:02:41.565: E/AndroidRuntime(8714): at java.lang.reflect.Method.invokeNative(Native Method)
12-30 11:02:41.565: E/AndroidRuntime(8714): at java.lang.reflect.Method.invoke(Method.java:507)
12-30 11:02:41.565: E/AndroidRuntime(8714): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-30 11:02:41.565: E/AndroidRuntime(8714): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-30 11:02:41.565: E/AndroidRuntime(8714): at dalvik.system.NativeStart.main(Native Method)
12-30 11:02:41.565: E/AndroidRuntime(8714): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class fragment
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
12-30 11:02:41.565: E/AndroidRuntime(8714): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.Activity.setContentView(Activity.java:1657)
12-30 11:02:41.565: E/AndroidRuntime(8714): at com.example.gameexpensetracker.Chart_screen_activity.onCreate(Chart_screen_activity.java:27)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
12-30 11:02:41.565: E/AndroidRuntime(8714): ... 11 more
12-30 11:02:41.565: E/AndroidRuntime(8714): Caused by: java.lang.ClassNotFoundException: android.view.fragment in loader dalvik.system.PathClassLoader[/data/app/com.example.gameexpensetracker-2.apk]
12-30 11:02:41.565: E/AndroidRuntime(8714): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
12-30 11:02:41.565: E/AndroidRuntime(8714): at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
12-30 11:02:41.565: E/AndroidRuntime(8714): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.createView(LayoutInflater.java:471)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:549)
12-30 11:02:41.565: E/AndroidRuntime(8714): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
12-30 11:02:41.565: E/AndroidRuntime(8714): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
12-30 11:02:41.565: E/AndroidRuntime(8714): ... 20 more
And here's the XML file:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Chartscreenactivity" >
<fragment
class="com.shinobicontrols.charts.ChartFragment"
android:id="#+id/chart"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
Here's the relevant code from the activity:
ChartFragment chartFragment =
(ChartFragment) getFragmentManager().findFragmentById(R.id.chart);
// Get the a reference to the ShinobiChart from the ChartFragment
ShinobiChart shinobiChart = chartFragment.getShinobiChart();
shinobiChart.setLicenseKey("UXbN8mQk0U/byjLMjAxNDAxMjJpbmZvQHNoaW5vYmljb250cm9scy5jb20=1rmCjO7D5wQQxbCcpm28bXkLR" +
"/7MtHh+IrFH93SspNfyW8J5Kf6xZfQ7dUJGFNDwdYkZGUaabHs3vezwOc9t+eJjMmVLkhRkVnnN47JIl3ir/cDGz36Ru2bC7SexLSZhkj0" +
"bXL69ISkSVMvyJZsbGm7gpby0=BQxSUisl3BaWf/7myRmmlIjRnMU2cA7q+/03ZX9wdj30RzapYANf51ee3Pi8m2rVW6aD7t6Hi4Qy5vv9xpa" +
"QYXF5T7XzsafhzS3hbBokp36BoJZg8IrceBj742nQajYyV7trx5GIw9jy/V6r0bvctKYwTim7Kzq+YPWGMtqtQoU=PFJTQUtleVZhbHVlPjxNb" +
"2R1bHVzPnh6YlRrc2dYWWJvQUh5VGR6dkNzQXUrUVAxQnM5b2VrZUxxZVdacnRFbUx3OHZlWStBK3pteXg4NGpJbFkzT2hGdlNYbHZDSjlKVGZQ" +
"TTF4S2ZweWZBVXBGeXgxRnVBMThOcDNETUxXR1JJbTJ6WXA3a1YyMEdYZGU3RnJyTHZjdGhIbW1BZ21PTTdwMFBsNWlSKzNVMDg5M1N4b2hCZlJ5RHd" +
"EeE9vdDNlMD08L01vZHVsdXM+PEV4cG9uZW50PkFRQUI8L0V4cG9uZW50PjwvUlNBS2V5VmFsdWU+");
SimpleDataAdapter<String, Double> dataAdapter = new SimpleDataAdapter<String, Double>();
dataAdapter.add(new DataPoint<String, Double>("Action", actionTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Adventure", adventureTotalDB));
dataAdapter.add(new DataPoint<String, Double>("MMO", MMOTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Puzzle", puzzleTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Racing", racingTotalDB));
dataAdapter.add(new DataPoint<String, Double>("RPG", rpgTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Sim", simulationTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Sports",sportsTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Strategy", strategyTotalDB));
dataAdapter.add(new DataPoint<String, Double>("Other", otherTotalDB));
PieSeries series = new PieSeries();
series.setDataAdapter(dataAdapter);
shinobiChart.addSeries(series);
Although ShinobiCharts supports down to API Level 9 (Gingerbread), Fragments were only introduced in API Level 11. Therefore you need to use the support library.
From the getting started guide:
Tip: To support devices down to API 9: Android 2.3 (Gingerbread) you will need to use SupportChartFragment instead of ChartFragment (in both the XML and the Java source). Additionally, you will need to change the ShinobiQuickStartActivity to extend FragmentActivity instead of Activity and use the getSupportFragmentManager() method instead of getFragmentManager(). Your project will need to reference the Android Support Library to do this.
(via: http://www.shinobicontrols.com/android/shinobicharts/quickstartguide/draw-a-simple-chart/)
I've made my Android app tablet optimized and I followed the tutorial here:
Everything is great, but I am trying to select an item (say, the 1st item) with a button in the ActionBar.
I tried this answer to use performItemClick but on I've got error reports of java.lang.IllegalStateException
in android.support.v4.app.ListFragment.ensureList, java.lang.IllegalStateException: Content view not yet created, and java.lang.NullPointerException
in android.content.ComponentName.<init>
I've tried checking if the ListView is null and still get the error reports on the Play Store. How do I properly select an item in my list programmatically?
Update to add logcat and the code is virtually identical to the tutorials in the links:
Logcat A:
java.lang.IllegalStateException: Content view not yet created
at android.support.v4.app.ListFragment.ensureList(ListFragment.java:328)
at android.support.v4.app.ListFragment.getListView(ListFragment.java:222)
at com.ccwilcox.meteorshower.MeteorList.showMeteorDetails(MeteorList.java:69)
at com.ccwilcox.meteorshower.MeteorList.onListItemClick(MeteorList.java:62)
at android.support.v4.app.ListFragment$2.onItemClick(ListFragment.java:58)
at android.widget.AdapterView.performItemClick(AdapterView.java:298)
at android.widget.AbsListView.performItemClick(AbsListView.java:1280)
at com.ccwilcox.meteorshower.MainActivity.viewUpcomingEvent(MainActivity.java:648)
at com.ccwilcox.meteorshower.MainActivity.onOptionsItemSelected(MainActivity.java:534)
at android.app.Activity.onMenuItemSelected(Activity.java:2606)
at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:361)
at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:1045)
at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:149)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
at com.android.internal.view.menu.ActionMenuView.invokeItem(ActionMenuView.java:592)
at com.android.internal.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:149)
at android.view.View.performClick(View.java:4222)
at android.view.View$PerformClick.run(View.java:17273)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4895)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
at dalvik.system.NativeStart.main(Native Method)
Logcat B:
java.lang.NullPointerException
at android.content.ComponentName.<init>(ComponentName.java:75)
at android.content.Intent.<init>(Intent.java:2874)
at com.ccwilcox.meteorshower.MeteorList.showMeteorDetails(MeteorList.java:86)
at com.ccwilcox.meteorshower.MeteorList.onListItemClick(MeteorList.java:62)
at android.support.v4.app.ListFragment$2.onItemClick(ListFragment.java:58)
at android.widget.AdapterView.performItemClick(AdapterView.java:284)
at android.widget.ListView.performItemClick(ListView.java:3701)
at com.ccwilcox.meteorshower.MainActivity.viewUpcomingEvent(MainActivity.java:648)
at com.ccwilcox.meteorshower.MainActivity.onOptionsItemSelected(MainActivity.java:534)
at android.app.Activity.onMenuItemSelected(Activity.java:2205)
at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:361)
at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:779)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:143)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:861)
at com.android.internal.view.menu.IconMenuView.invokeItem(IconMenuView.java:532)
at com.android.internal.view.menu.IconMenuItemView.performClick(IconMenuItemView.java:122)
at android.view.View$PerformClick.run(View.java:9152)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3687)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)
Update 2
And here is the code that is causing the problem:
if (mListFragment.listView != null) {
mListFragment.listView.performItemClick(mListFragment.listView.getAdapter().getView(position, null, null), position, mListFragment.listView.getAdapter().getItemId(position));
}
I am trying to write my first Android app, and I'm having trouble. I wrote a simple Java program to find the factors of a number provided by the user, and I'd like to port it over to Java. I have an XML file for the interface, which seemed to run OK until I added the first Java class. Now it won't run, and log.cat says that there's a null pointer exception. So far, I only have stubs, but it seems like it should run OK with what I've done to this point. I'm including the log.cat text, but I'm too new it this to make much sense out of it.
There may be more than one problem. After adding the Java file I began to get run-time errors right away, but I don't think they were null pointer exceptions. I think that started when I made changes to fix what was already causing problems.
Any help is appreciated.
Here is the Java file:
import android.app.Activity; <br>
import android.os.Bundle; <br>
import android.widget.Button; <br>
import android.widget.EditText; <br>
import android.widget.TextView; <br>
public class AndroidFactoringActivity extends Activity {
// Instance Variables
EditText userNumber;
Button factorButton;
TextView resultsField;
int factorResults;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
factorButton = (Button) findViewById(R.id.factorButton);
userNumber = (EditText) findViewById(R.id.userNumber);
factorResults = 1;
resultsField.setText(String.valueOf(factorResults));
}
}
Here is main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/askField"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/ask"
android:textSize="24dp" />
<EditText
android:id="#+id/userNumber"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="number" >
<requestFocus />
</EditText>
<Button
android:id="#+id/factorButton"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/click" />
<TextView
android:id="#+id/resultsField"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/tell"
android:textSize="24dp" />
</LinearLayout>
Here are the log.cat results:
03-31 23:58:53.579: D/AndroidRuntime(2804): Shutting down VM
03-31 23:58:53.589: W/dalvikvm(2804): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
03-31 23:58:53.589: E/AndroidRuntime(2804): Uncaught handler: thread main exiting due to uncaught exception
03-31 23:58:53.650: E/AndroidRuntime(2804): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.dave_b.factoring/net.dave_b.factoring.AndroidFactoringActivity}: java.lang.NullPointerException
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.os.Handler.dispatchMessage(Handler.java:99)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.os.Looper.loop(Looper.java:123)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread.main(ActivityThread.java:4363)
03-31 23:58:53.650: E/AndroidRuntime(2804): at java.lang.reflect.Method.invokeNative(Native Method)
03-31 23:58:53.650: E/AndroidRuntime(2804): at java.lang.reflect.Method.invoke(Method.java:521)
03-31 23:58:53.650: E/AndroidRuntime(2804): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
03-31 23:58:53.650: E/AndroidRuntime(2804): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
03-31 23:58:53.650: E/AndroidRuntime(2804): at dalvik.system.NativeStart.main(Native Method)
03-31 23:58:53.650: E/AndroidRuntime(2804): Caused by: java.lang.NullPointerException
03-31 23:58:53.650: E/AndroidRuntime(2804): at net.dave_b.factoring.AndroidFactoringActivity.onCreate(AndroidFactoringActivity.java:26)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-31 23:58:53.650: E/AndroidRuntime(2804): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
03-31 23:58:53.650: E/AndroidRuntime(2804): ... 11 more
03-31 23:58:53.679: I/dalvikvm(2804): threadid=7: reacting to signal 3
03-31 23:58:53.679: E/dalvikvm(2804): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
03-31 23:59:57.629: I/Process(2804): Sending signal. PID: 2804 SIG: 9
04-01 00:07:36.129: D/AndroidRuntime(3040): Shutting down VM
04-01 00:07:36.129: W/dalvikvm(3040): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
04-01 00:07:36.139: E/AndroidRuntime(3040): Uncaught handler: thread main exiting due to uncaught exception
04-01 00:07:36.159: E/AndroidRuntime(3040): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.dave_b.factoring/net.dave_b.factoring.AndroidFactoringActivity}: java.lang.NullPointerException
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.os.Handler.dispatchMessage(Handler.java:99)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.os.Looper.loop(Looper.java:123)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread.main(ActivityThread.java:4363)
04-01 00:07:36.159: E/AndroidRuntime(3040): at java.lang.reflect.Method.invokeNative(Native Method)
04-01 00:07:36.159: E/AndroidRuntime(3040): at java.lang.reflect.Method.invoke(Method.java:521)
04-01 00:07:36.159: E/AndroidRuntime(3040): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
04-01 00:07:36.159: E/AndroidRuntime(3040): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
04-01 00:07:36.159: E/AndroidRuntime(3040): at dalvik.system.NativeStart.main(Native Method)
04-01 00:07:36.159: E/AndroidRuntime(3040): Caused by: java.lang.NullPointerException
04-01 00:07:36.159: E/AndroidRuntime(3040): at net.dave_b.factoring.AndroidFactoringActivity.onCreate(AndroidFactoringActivity.java:26)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-01 00:07:36.159: E/AndroidRuntime(3040): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
04-01 00:07:36.159: E/AndroidRuntime(3040): ... 11 more
04-01 00:07:36.199: I/dalvikvm(3040): threadid=7: reacting to signal 3
04-01 00:07:36.199: E/dalvikvm(3040): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
04-01 00:07:40.329: I/Process(3040): Sending signal. PID: 3040 SIG: 9
resultsField.setText(String.valueOf(factorResults));
resultsField is null and you are trying to set value on null.
resultsField= (TextView ) findViewById(R.id.userNumber);
Get textview instance before setting value, otherwise resultsField will be null and all operations on null reference results in NullPointerException.
You got a null pointer because you didnt intialise the variable resultsField (you just declared it) .
As you used
userNumber = (EditText) findViewById(R.id.userNumber);
you must even initialise the reference resultsField.
This can be done using
resultsField= (TextView ) findViewById(R.id.resultsField);
in the onCreate() after the statement setContentView()
You need to initialize the userNumer and resultsFiled as follows
userNumber = (EditText) findViewById(R.id.userNumber);
resultsField= (TextView ) findViewById(R.id.resultsField);
When I run my android application it gives an error "The application has stopped working,please try again". Please help me to solve this problem. i have created a method which gets called when the button gets clicked. When I include the code for calling another class in this method it shows the above error & when I remove that code it neither shows the error nor goes ahead when listview etc. gets clicked. Can you please check my code and help me please.
CODE:
public void myClickHandler(View view)
{
//Toast.makeText(this, "yesss",Toast.LENGTH_LONG).show();
setContentView(R.layout.screen1);
ListAdapter adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, city);
ListView FirstProjectActivity = (ListView) findViewById(R.id.mylist1);
FirstProjectActivity.setAdapter(adapter);
Intent myIntent = new Intent(FirstProjectActivity.this,
City.class);
FirstProjectActivity.this.startActivity(myIntent);
//startActivity(new Intent(FirstProjectActivity.this, City.class));
}
LOGCAT is as follows:
03-02 18:56:28.136: D/AndroidRuntime(316): Shutting down VM
03-02 18:56:28.136: W/dalvikvm(316): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-02 18:56:28.226: E/AndroidRuntime(316): FATAL EXCEPTION: main
03-02 18:56:28.226: E/AndroidRuntime(316): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.FirstProject/com.example.FirstProject.FirstProjectActivity}: java.lang.NullPointerException
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.os.Looper.loop(Looper.java:123)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-02 18:56:28.226: E/AndroidRuntime(316): at java.lang.reflect.Method.invokeNative(Native Method)
03-02 18:56:28.226: E/AndroidRuntime(316): at java.lang.reflect.Method.invoke(Method.java:521)
03-02 18:56:28.226: E/AndroidRuntime(316): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-02 18:56:28.226: E/AndroidRuntime(316): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-02 18:56:28.226: E/AndroidRuntime(316): at dalvik.system.NativeStart.main(Native Method)
03-02 18:56:28.226: E/AndroidRuntime(316): Caused by: java.lang.NullPointerException
03-02 18:56:28.226: E/AndroidRuntime(316): at com.example.FirstProject.FirstProjectActivity.onCreate(FirstProjectActivity.java:37)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-02 18:56:28.226: E/AndroidRuntime(316): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-02 18:56:28.226: E/AndroidRuntime(316): ... 11 more
03-02 18:56:35.396: I/Process(316): Sending signal. PID: 316 SIG: 9
03-02 19:02:51.836: D/AndroidRuntime(351): Shutting down VM
03-02 19:02:51.836: W/dalvikvm(351): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-02 19:02:51.866: E/AndroidRuntime(351): FATAL EXCEPTION: main
03-02 19:02:51.866: E/AndroidRuntime(351): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.FirstProject/com.example.FirstProject.FirstProjectActivity}: java.lang.NullPointerException
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.os.Handler.dispatchMessage(Handler.java:99)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.os.Looper.loop(Looper.java:123)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-02 19:02:51.866: E/AndroidRuntime(351): at java.lang.reflect.Method.invokeNative(Native Method)
03-02 19:02:51.866: E/AndroidRuntime(351): at java.lang.reflect.Method.invoke(Method.java:521)
03-02 19:02:51.866: E/AndroidRuntime(351): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-02 19:02:51.866: E/AndroidRuntime(351): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-02 19:02:51.866: E/AndroidRuntime(351): at dalvik.system.NativeStart.main(Native Method)
03-02 19:02:51.866: E/AndroidRuntime(351): Caused by: java.lang.NullPointerException
03-02 19:02:51.866: E/AndroidRuntime(351): at com.example.FirstProject.FirstProjectActivity.onCreate(FirstProjectActivity.java:37)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
03-02 19:02:51.866: E/AndroidRuntime(351): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
03-02 19:02:51.866: E/AndroidRuntime(351): ... 11 more
03-02 19:03:03.647: I/Process(351): Sending signal. PID: 351 SIG: 9
03-02 20:11:17.722: W/KeyCharacterMap(379): No keyboard for id 0
03-02 20:11:17.926: W/KeyCharacterMap(379): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
03-02 20:11:28.441: D/dalvikvm(379): GC_EXPLICIT freed 3121 objects / 172672 bytes in 1696ms
03-03 01:03:02.696: W/KeyCharacterMap(406): No keyboard for id 0
03-03 01:03:02.696: W/KeyCharacterMap(406): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
03-03 01:03:08.566: D/dalvikvm(406): GC_EXPLICIT freed 2874 objects / 162408 bytes in 192ms
03-03 01:33:06.566: D/AndroidRuntime(432): Shutting down VM
03-03 01:33:06.566: W/dalvikvm(432): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:33:06.726: E/AndroidRuntime(432): FATAL EXCEPTION: main
03-03 01:33:06.726: E/AndroidRuntime(432): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:33:06.726: E/AndroidRuntime(432): at android.view.View$1.onClick(View.java:2072)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.view.View.performClick(View.java:2408)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.view.View$PerformClick.run(View.java:8816)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.os.Looper.loop(Looper.java:123)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:33:06.726: E/AndroidRuntime(432): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:33:06.726: E/AndroidRuntime(432): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:33:06.726: E/AndroidRuntime(432): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:33:06.726: E/AndroidRuntime(432): at dalvik.system.NativeStart.main(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:33:06.726: E/AndroidRuntime(432): at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:69)
03-03 01:33:06.726: E/AndroidRuntime(432): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:33:06.726: E/AndroidRuntime(432): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.view.View$1.onClick(View.java:2067)
03-03 01:33:06.726: E/AndroidRuntime(432): ... 11 more
03-03 01:33:06.726: E/AndroidRuntime(432): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:33:06.726: E/AndroidRuntime(432): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:33:06.726: E/AndroidRuntime(432): at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:33:06.726: E/AndroidRuntime(432): ... 15 more
03-03 01:33:08.956: I/Process(432): Sending signal. PID: 432 SIG: 9
03-03 01:34:05.387: D/AndroidRuntime(460): Shutting down VM
03-03 01:34:05.387: W/dalvikvm(460): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:34:05.417: E/AndroidRuntime(460): FATAL EXCEPTION: main
03-03 01:34:05.417: E/AndroidRuntime(460): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:34:05.417: E/AndroidRuntime(460): at android.view.View$1.onClick(View.java:2072)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.view.View.performClick(View.java:2408)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.view.View$PerformClick.run(View.java:8816)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.os.Looper.loop(Looper.java:123)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:34:05.417: E/AndroidRuntime(460): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:34:05.417: E/AndroidRuntime(460): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:34:05.417: E/AndroidRuntime(460): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:34:05.417: E/AndroidRuntime(460): at dalvik.system.NativeStart.main(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:34:05.417: E/AndroidRuntime(460): at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:34:05.417: E/AndroidRuntime(460): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:34:05.417: E/AndroidRuntime(460): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.view.View$1.onClick(View.java:2067)
03-03 01:34:05.417: E/AndroidRuntime(460): ... 11 more
03-03 01:34:05.417: E/AndroidRuntime(460): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:34:05.417: E/AndroidRuntime(460): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:34:05.417: E/AndroidRuntime(460): at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:34:05.417: E/AndroidRuntime(460): ... 15 more
03-03 01:34:11.016: I/Process(460): Sending signal. PID: 460 SIG: 9
03-03 01:35:33.547: D/AndroidRuntime(490): Shutting down VM
03-03 01:35:33.557: W/dalvikvm(490): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:35:33.577: E/AndroidRuntime(490): FATAL EXCEPTION: main
03-03 01:35:33.577: E/AndroidRuntime(490): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:35:33.577: E/AndroidRuntime(490): at android.view.View$1.onClick(View.java:2072)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.view.View.performClick(View.java:2408)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.view.View$PerformClick.run(View.java:8816)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.os.Looper.loop(Looper.java:123)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:35:33.577: E/AndroidRuntime(490): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:35:33.577: E/AndroidRuntime(490): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:35:33.577: E/AndroidRuntime(490): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:35:33.577: E/AndroidRuntime(490): at dalvik.system.NativeStart.main(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:35:33.577: E/AndroidRuntime(490): at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:35:33.577: E/AndroidRuntime(490): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:35:33.577: E/AndroidRuntime(490): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.view.View$1.onClick(View.java:2067)
03-03 01:35:33.577: E/AndroidRuntime(490): ... 11 more
03-03 01:35:33.577: E/AndroidRuntime(490): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:35:33.577: E/AndroidRuntime(490): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:35:33.577: E/AndroidRuntime(490): at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:35:33.577: E/AndroidRuntime(490): ... 15 more
03-03 01:35:39.176: I/Process(490): Sending signal. PID: 490 SIG: 9
03-03 01:36:06.947: D/AndroidRuntime(517): Shutting down VM
03-03 01:36:06.947: W/dalvikvm(517): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-03 01:36:06.967: E/AndroidRuntime(517): FATAL EXCEPTION: main
03-03 01:36:06.967: E/AndroidRuntime(517): java.lang.IllegalStateException: Could not execute method of the activity
03-03 01:36:06.967: E/AndroidRuntime(517): at android.view.View$1.onClick(View.java:2072)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.view.View.performClick(View.java:2408)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.view.View$PerformClick.run(View.java:8816)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.os.Looper.loop(Looper.java:123)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.app.ActivityThread.main(ActivityThread.java:4627)
03-03 01:36:06.967: E/AndroidRuntime(517): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:36:06.967: E/AndroidRuntime(517): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-03 01:36:06.967: E/AndroidRuntime(517): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-03 01:36:06.967: E/AndroidRuntime(517): at dalvik.system.NativeStart.main(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517): Caused by: java.lang.reflect.InvocationTargetException
03-03 01:36:06.967: E/AndroidRuntime(517): at com.example.FirstProject.FirstProjectActivity.myClickHandler(FirstProjectActivity.java:70)
03-03 01:36:06.967: E/AndroidRuntime(517): at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:36:06.967: E/AndroidRuntime(517): at java.lang.reflect.Method.invoke(Method.java:521)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.view.View$1.onClick(View.java:2067)
03-03 01:36:06.967: E/AndroidRuntime(517): ... 11 more
03-03 01:36:06.967: E/AndroidRuntime(517): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.FirstProject/com.example.FirstProject.City}; have you declared this activity in your AndroidManifest.xml?
03-03 01:36:06.967: E/AndroidRuntime(517): at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.app.Instrumentation.execStartActivity(Instrumentation.java:1378)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.app.Activity.startActivityForResult(Activity.java:2817)
03-03 01:36:06.967: E/AndroidRuntime(517): at android.app.Activity.startActivity(Activity.java:2923)
03-03 01:36:06.967: E/AndroidRuntime(517): ... 15 more
03-03 01:36:13.306: I/Process(517): Sending signal. PID: 517 SIG: 9
When you want to detect if you click on an item you need to implement the onItemClickedListener i will give you an example below like i would do it:
listView.setOnItemClickListener(new MyOnitemClickListener());
//no i make my own class that impelemnts the onitemclicklistener
public class MyOnitemClickListener implements OnItemClickListener {
private int position = 0;
public void onItemClick(AdapterView<?> parent, View view, int pos,
long lat) {
// clicked on parent.getid()
if (parent.getId() == R.id.listView) {
//do something
}
}
}
after a crash, try looking for the first couple of red lines the LOGCAT spews to you as they usually explain what happened.
the following line :
java.lang.NullPointerException
(in line 5) showed up on you log, it usually means your trying to use an uninitialized object.
refer to:
What is a NullPointerException, and how do I fix it?