Develop Reference

setOnClickListener not working as expected

First of all, I'm a newbie to android.
I have three activities in my Application. i.e, MainActivity, TC and navigation_drawer.
The user enters in MainActivity in the beginning, provided his/her name and enters TC on a button click (Working perfectly fine). Here inside TC there are two buttons "Agree", "Do not Agree" as shown below.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".TC">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/agree"
android:text="Agree"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/not_agree"
android:text="Do not Agree"
android:layout_below="#id/agree"/>
</RelativeLayout>
Now, if the user clicks on Agree it should go to navigation_drawer and if clicked on Do not agree it should go back to MainActivity. The code for it is:
public class TC extends AppCompatActivity {
private Button Agree, NotAgree;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_t_c);
Agree = (Button) findViewById(R.id.agree);
NotAgree = (Button) findViewById(R.id.not_agree);
Agree.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(TC.this, "Agree", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(TC.this, navigation_drawer.class);
startActivity(intent);
}
});
NotAgree.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(TC.this, "Not Agree", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(TC.this, MainActivity.class);
startActivity(intent);
}
});
}
}
Toast was added just to check if the right method was called or no (And it is calling the right method)
The AndroidManifest.xml contains(I am not sure if this will help):
<activity android:name=".TC" android:noHistory="true"/>
<activity android:name=".navigation_drawer" />
<activity
android:name=".MainActivity"
android:noHistory="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
The problem is, for some reason no matter which button I click it always redirects to navigation_drawer also for both the buttons the Toast message was shown as expected.
I do not know what am I missing here, please suggest a solution. Thank you.

I don't see anything wrong with your code and should work but it seems like you are starting the navigation_drawer activity in both button clicks.
So I suggest you declare and initialize both button's Intent variables outside the setOnClickListner() block by giving each Intent variables different name such as intent1 and intent2 and try running it again.

test this :
remove android:noHistory="true" in Manifest
and after startActivity(....) call finish()

Android buttons/app not working

I must be doing something very stupid. This is my second app - the first worked fine (honest).
I've just got a basic title screen with a button on it but nothing happens when I click on the button. The screen appears correctly but no response from the button - I've tried it in debug but nothing...no error, no info message, zilch (I'm using the AVD).
This is my code...
Manifest:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.spyeye"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/spyEyeTheme" >
<activity
android:name="com.example.spyeye.TitleScreen"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.spyeye.createNewGameActivity"
android:label="#string/app_name"
android:parentActivityName="com.example.spyeye.TitleScreen" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.spyeye.TitleScreen" />
</activity>
XML file:
<RelativeLayout 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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".TitleScreen" >
<ImageView
android:src="#drawable/spyeyelogo"
android:contentDescription="#string/logo"
android:layout_centerHorizontal="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/logo" />
<Button
android:id="#+id/newBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/logo"
android:layout_centerHorizontal="true"
android:layout_marginTop="50dp"
android:onClick="newGame"
android:text="#string/newTxt" />
Java file:
public class TitleScreen extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_title_screen);
}
public void newGame (View v) {
// create intent to start another activity
Intent newGameIntent = new Intent(this, createNewGameActivity.class);
startActivity(newGameIntent);
}
}
The only major difference between this and my other app is that I have now tried to use a single style file and I've re-designed my own buttons:
<style name="spyEyeTheme" parent="android:Theme.Light">
<item name="android:buttonStyle">#style/myButton</item>
</style>
<style name="myButton" parent="android:Theme.Light">
<item name="android:background">#008080</item>
<item name="android:textColor">#FFFFFF</item>
<item name="android:textSize">24sp</item>
<item name="android:typeface">sans</item>
<item name="android:padding">10sp</item>
</style>
Anyone see the obvious mistake I must have made?

Personally I am really not a big fan of that android:onClick="newGame" stuff. You should try it the good old-fashioned way, like this:
public class TitleScreen extends Activity {
private Button newBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_title_screen);
this.newBtn = (Button) findViewById(R.id.newBtn);
this.newBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent newGameIntent = new Intent(this, createNewGameActivity.class);
startActivity(newGameIntent);
}
});
}
}
Or like this:
public class TitleScreen extends Activity implements View.OnClickListener {
private Button newBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_title_screen);
this.newBtn = (Button) findViewById(R.id.newBtn);
this.newBtn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
Intent newGameIntent = new Intent(this, createNewGameActivity.class);
startActivity(newGameIntent);
}
}
If you are dealing with multiple Buttons you can handle them in one OnClickListener like this:
private final View.OnClickListener clickListener = new View.OnClickListener() {
#Override
public void onClick(View view) {
final int id = view.getId();
switch (id) {
case R.id.newBtn:
Intent newGameIntent = new Intent(this, createNewGameActivity.class);
startActivity(newGameIntent);
break;
case R.id.otherButton:
Toast.makeText(this, "Other Button clicked!", Toast.LENGTH_SHORT).show();
break;
case R.id.cancelButton:
...
break;
}
}
};
You get the id of the calling View and use a switch to differentiate between the specific Buttons. For example in your Activity you can implement this like this:
public class TitleScreen extends Activity implements View.OnClickListener {
private Button newBtn;
private Button otherBtn;
private Button cancelBtn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_title_screen);
this.newBtn = (Button) findViewById(R.id.newBtn);
this.newBtn.setOnClickListener(this);
this.otherBtn = (Button) findViewById(R.id.otherBtn);
this.otherBtn.setOnClickListener(this);
this.cancelBtn = (Button) findViewById(R.id.cancelBtn);
this.cancelBtn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
final int id = view.getId();
switch (id) {
case R.id.newBtn:
Intent newGameIntent = new Intent(this, createNewGameActivity.class);
startActivity(newGameIntent);
break;
case R.id.otherBtn:
Toast.makeText(this, "Other Button clicked!", Toast.LENGTH_SHORT).show();
break;
case R.id.cancelBtn:
...
break;
}
}
}
A few things that caught my eye:
The names of classes are supposed to start with an upper case letter, so instead of createNewGameActivity you Activity should be called CreateNewGameActivity.
Use Fragments. The golden age of Activities is over. Since Fragments were introduced Activities are just supposed to be containers for the Fragments. So even if you just have one Button in your layout you should have an empty Activity which just contains one Fragment and in that Fragment you implement your UI and logic.
Don't use android:onClick. There is no indication in the code that this method will be called at all. And there is no reason for the layout to assume that such a method exists anywhere in the View, Fragment or Activity which loads the layout. And aside from that it isn't even that convenient. In 99,9% of all cases in which you need to set an OnClickListener you also need to do other stuff with the Button and then you need the reference anyway. android:onClick just clutters your code and makes it more confusing. it spreads implementation details out and obscures it to the developer. That the layout knows or even defines specific implementation details is in itself already pretty bad.

XML Parser Android - Calling New Activity

I have a question about xml parser in android. I am creating button information in the xml. I am getting its height,width,color and so on. I am creating all buttons in a function. Now i want to do the following. When i click the buttons, new android page opens. As far as i know i will do it by creating new activities.
btn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i=new Intent(MainActivity.this,MainActivity2.class);
startActivity(i);
}
});
I am writing this on my function which i create all buttons.when i do this it does not work.can somebody help me?

In your Activity :
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view_main);
View btnTapOnMe = findViewById(R.id.btnTapOnMe);
btnTapOnMe.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i=new Intent(MainActivity.this,MainActivity2.class);
startActivity(i);
}
});
}
}
view_main.xml :
<RelativeLayout 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" >
<Button
android:id="#+id/btnTapOnMe"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tap on Me" />
</RelativeLayout>
AndroidManifest.xml :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.yourpackage"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19"/>
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme">
<activity
android:name="com.yourpackage.MainActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
<activity android:name="com.yourpackage.MainActivity2"/>
</application>
</manifest>
Should work like a charm
UPDATE:
Don't ever use AbsoluteLayout it is deprecated
This class was deprecated in API level 3.
Use FrameLayout, RelativeLayout or a custom layout instead.
First of all change it to Frame or Relative layout.
Here what i get in my example below :
public class MainActivity extends FragmentActivity {
public void AddAllButtons() {
AbsoluteLayout Layout = (AbsoluteLayout) findViewById(R.id.layout1);
Button btn = new Button(this);
btn.setText("Test case");
Layout.addView(btn);
AbsoluteLayout.LayoutParams absParams = (AbsoluteLayout.LayoutParams) btn.getLayoutParams();
absParams.x = 100;
absParams.y = 100;
absParams.width = 150;
btn.setLayoutParams(absParams);
btn.setBackgroundColor(Color.GREEN);
btn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(MainActivity.this, SearchActivity.class);
startActivity(i);
}
});
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view_main);
AddAllButtons();
}
}
and here is xml file :
<RelativeLayout 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"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<Button
android:id="#+id/btnTapOnMe"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tap on Me"/>
<AbsoluteLayout
android:id="#+id/layout1"
android:layout_below="#+id/btnTapOnMe"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</AbsoluteLayout>
</RelativeLayout>

Splash screen in Android Application

I am modifying an open source application and want to add a splash screen to it,
Can some one help me in it?
When the application starts a black screen appears for 2 to 3 seconds and then the application appears....
In the code the activity main.xml is started, I have read some forums that the splash.xml file should be created and with the help of threads splash activity and main activity should be executed parallel. Is it the right approach...?
#
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
instance = this;
setContentView(R.layout.main);
#
Would it not be possible that I modify main.xml and put the image (splash) in main.xml so that it appears from there?

Use class SplashScreen as under
public class Splashscreen extends Activity {
private static final int SPLASH_DISPLAY_TIME = 3000; /* 3 seconds */
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.splash);
new Handler().postDelayed(new Runnable() {
public void run() {
Intent mainIntent = new Intent(Splashscreen.this,
MainActivity.class);
Splashscreen.this.startActivity(mainIntent);
Splashscreen.this.finish();
overridePendingTransition(R.anim.mainfadein,
R.anim.splashfadeout);
}
}, SPLASH_DISPLAY_TIME);
}
}
**Add mainfadein.xml & splashfadeout.xml in res->anim folder
mainfadein.xml**
<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/accelerate_interpolator"
android:fromAlpha="0.0"
android:toAlpha="1.0"
android:duration="1000">
</alpha>
splashfadeout.xml
<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="#android:anim/decelerate_interpolator"
android:zAdjustment="top"
android:fromAlpha="1.0"
android:toAlpha="0.0"
android:duration="1000" >
</alpha>
and add splash.xml just Add an ImageView and set its background as screen & add image of urchoice in layout
And make Splashscreen class as Launcher and make all other class as HOME in manifest file

Don't forget to consider that the user might want to quit your app before the splash-delay is over.
So clear any pending runnables/messages when the user exits your app.
Example can be found here

Splash activity
public class LaunchScreen extends Activity {
public static final long TIME = 3000;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.logo);
Protocol.getInstance(this);
Thread welcomeThread = new Thread() {
#Override
public void run() {
try {
sleep(TIME);
} catch (Exception e) {
Log.e(getClass().getName(), e.toString());
} finally {
startActivity(new Intent(LaunchScreen.this,MainScreen.class));
finish();
}
}
};
welcomeThread.start();
}
}
logo.xml file:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="right"
>
<ImageView
android:id="#+id/logo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/logo"
android:layout_centerInParent="true"
>
</ImageView>
</RelativeLayout>
in AndroidManifest :
activity android:name=".LaunchScreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainScreen" android:label="#string/app_name" ></activity>

Do I have to start some kind of sqlite server before using it in android application

well, almost everything is in the question, I have a problem with program which should use the sqlite, it still returns the "unexpected error", I was just wondering do I have to start some kind of server, deamon or service?
androidManifest[ snippet ]
<activity android:name=".About">
android:label="#string/about_title"
android:theme="#android:style/Theme.Dialog" >
</activity>
<activity android:name=".Exit">
andorid:label="#string/exit_title">
</activity>
<activity android:name=".Options">
</activity>
<activity android:name=".Start">
</activity>
<activity android:name=".Create">
</activity>
</application>
AndroidSQLite
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.sql);
TextView listContent = (TextView)findViewById(R.id.contentlist);
mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.openToWrite();
mySQLiteAdapter.deleteAll();
mySQLiteAdapter.insert("ABCDE");
mySQLiteAdapter.insert("FGHIJK");
mySQLiteAdapter.insert("1234567");
mySQLiteAdapter.insert("890");
mySQLiteAdapter.insert("Testing");
mySQLiteAdapter.close();
mySQLiteAdapter = new SQLiteAdapter(this);
mySQLiteAdapter.openToRead();
String contentRead = mySQLiteAdapter.queueAll();
mySQLiteAdapter.close();
listContent.setText(contentRead);
}
sql.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/app_name"
/>
<ListView
android:id="#+id/contentlist"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>
main.xml [snippet]
<Button
android:id="#+id/where_button"
android:onClick="WhereCl"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/where_label" />
code responsible for button Where Am I?
mainActivity.java
public class MainActivity extends Activity
{
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
View startButton = findViewById(R.id.start_button);
View whereButton = findViewById(R.id.where_button);
View aboutButton = findViewById(R.id.about_button);
View exitButton = findViewById(R.id.exit_button);
}
public void OptionsCl(View v){
startActivity(new Intent(this,Options.class));
}
public void WhereCl(View v){
startActivity(new Intent(this,AndroidSQLite.class));
}
public void StartCl(View v){
Intent idd = new Intent(this,Start.class);
startActivity(idd);
}
public void AboutCl(View v){
startActivity(new Intent(this,About.class));
}
public void ExitCl(View v){
finish();
}
}
the error I receive is similar to this which come up with unregistred action, but the action is registred [ check the code ]
it is just "the application blabla (menu.dot) has stopped unexpectedly. Please try again" Force close.

Android SQLite is readymade library. So you don't need to start any Service, server or demon. Just to initiate a database class extending SQLite DatabaseHelper class and use it.
Thanks.