Only works in Main Activity? - android

So I have a code, that's only works in the MainActivity, and I don't know how to make it work, in the second activity.
import android.app.Activity;
import android.content.res.Resources;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.Random;
public class MainActivity extends Activity {
private String[] myString;
private static final Random rgenerator = new Random();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Resources res = getResources();
myString = res.getStringArray(R.array.myArray);
String q = myString[rgenerator.nextInt(myString.length)];
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(q);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
public void ButtonOnClick (View v) {
Button button = (Button) v;
setContentView(R.layout.activity_szabaly);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
When I start my app, in the first activity the text is changing(because it's a random text changing code), but when I press the button, that makes me go to the second activity, nothing happens, no action in the second activity.
What am I doing wrong?
My Manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.example" >
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".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=".Szabaly"
android:label="#string/title_activity_szabaly" >
</activity>
</application>
</manifest>

you add the android:onClick attribute in the layout ? this is bad practice
better implementing View.OnClickListener
public class MainActivity extends Activity {
private String[] myString;
private static final Random rgenerator = new Random();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Resources res = getResources();
myString = res.getStringArray(R.array.myArray);
String q = myString[rgenerator.nextInt(myString.length)];
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(q);
//finde button
Button button =(Button)findViewById(R.id.button);
//set OnClickListener
button.setOnClickListener(this);
}
#Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button:
Intent intent = new Intent(this, Szabaly.class);
startActivity(intent );
break;
}
}
}

You're not actually starting a new activity on your button click. Instead you're just changing your view. This will not be cause to call the onCreate method again.
public void ButtonOnClick (View v) {
Button button = (Button) v;
setContentView(R.layout.activity_szabaly);
}
This code is only changing the view. To start a new activity you'd need to create a new class that extends Activity (just like MainActivity) and register it in the AndroidManifest.xml.
Then you'll be able to start the new activity on click by the following
public void ButtonOnClick (View v) {
Intent i = new Intent(this, NewActivity.class);
startActivity(i);
}
See this question for more detail on starting a new Activity from a button click.

Related

The startactivity(intent) method causes an error. Why?

I want after a click on the OK button the MenuActivity to be shown. I have already searched on the Internet to find an answer and tried everything. I haave the activity declared in the AndroidManifest and I also tried to use Intent(this, MenuActivity.class) and also the one with the action inside but it doesn't work.
MainActivity:
package com.jamesjohnson.chronos;
import android.app.AlertDialog;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.*;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import com.jamesjohnson.chronos.R;
public class MainActivity extends ActionBarActivity implements OnClickListener {
private static final String TAG = "MainActivity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.setTitle("Willkommen");
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(this);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
switch(id) {
case R.id.action_mainmenu:
startActivity(new Intent("com.jamesjohnson.chronos.MenuActivity"));
return true;
case R.id.action_settings:
showMessageBox("Es gibt leider noch keine Einstellungen. Wir arbeiten daran!", true, true);
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onClick(View v) {
try {
Intent intent = new Intent(MainActivity.this, MenuActivity.class);
Context ctx = this;
intent.setClassName(ctx, "com.jamesjohnson.chronos.MenuActivity");
intent.setAction("com.jamesjohnson.chronos.MenuActivity");
if ((intent.getAction() == "com.jamesjohnson.chronos.MenuActivity") || (intent.getClass() != null)) {
MainActivity.this.startActivity(intent);
showMessageBox("Button has been pressed " + intent.toString(), true, true);
}
else {
showMessageBox("Error : Hauptmenü ist nicht erreichbar", true, true);
}
}
catch (ActivityNotFoundException an) {
showMessageBox("Error :" + an.getMessage(), true, true);
}
catch (Exception e) {
showMessageBox("Error :" + e.getMessage(), true, true);
}
}
protected void showMessageBox(String message, boolean showOKbutton, boolean canceable) {
AlertDialog.Builder dlgAlert = new AlertDialog.Builder(MainActivity.this);
dlgAlert.setMessage(message);
dlgAlert.setTitle("Chronos");
if (showOKbutton) {
dlgAlert.setPositiveButton("OK", null);
}
if (canceable) {
dlgAlert.setCancelable(true);
}
dlgAlert.create().show();
}
}
Here's my AndroidManifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.jamesjohnson.chronos"
android:versionCode="1"
android:versionName="1.0.1
" >
<application
android:allowBackup="true"
android:debuggable="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".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=".MenuActivity"
android:label="#string/title_activity_menu"
android:parentActivityName=".MainActivity" >
<intent-filter>
<action android:name="com.jamesjohnson.chronos.MenuActivity" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
<!-- Parent activity meta-data to support 4.0 and lower -->
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.jamesjohnson.chronos.MainActivity" />
</activity>
</application>
</manifest>
And finally here's the MenuActivity:
package com.jamesjohnson.chronos;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
public class MenuActivity extends ListActivity {
private static final String TAG = "MenuActivity";
static final String[] ENTRIES = new String[] {"Kunden", "Projekte", "Leistungen", "Zeiten"};
ListView listView = getListView();
#Override
protected void onCreate(Bundle savedInstanceState) {
showMessageBox("Activity is beeing created", true, true);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu);
this.setTitle("Hauptmenü");
this.setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, ENTRIES));
listView.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch (position) {
case 0:
showMessageBox("Kunden", true, true);
break;
case 1:
showMessageBox("Projekte", true, true);
break;
case 2:
showMessageBox("Leistungen", true, true);
break;
case 3:
showMessageBox("Zeiten", true, true);
break;
default:
showMessageBox("Error: Undefined index", true, true);
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
protected void showMessageBox(String message, boolean showOKbutton, boolean canceable) {
AlertDialog.Builder dlgAlert = new AlertDialog.Builder(MenuActivity.this);
dlgAlert.setMessage(message);
dlgAlert.setTitle("Chronos");
if (showOKbutton) {
dlgAlert.setPositiveButton("OK", null);
}
if (canceable) {
dlgAlert.setCancelable(true);
}
dlgAlert.create().show();
}
}
Unfortunately I can't show you my Logcat because it doesn't work on my computer. (I always have to export the APK to test the App).
P.S. I am working with Android Studio 1.0.1
...Please HELP ME !
To open a new activity you simply have to call it like this inside the onClick method.
Intent intent = new Intent(v.getContext(), MenuActivity.class);
startActivity(intent);
So your onClick method will look like this.
#Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), MenuActivity.class);
startActivity(intent);
}
Hope this helps.
Is because you say MainActivity.this, but you aren't in the MainActivity context.
You could make a reference of your current context in onCreate() and save it in a field:
private Context context;
#Override
protected void onCreate(Bundle savedInstanceState) {
context = this;
//rest of your code here
}
and use it as:
Intent intent = new Intent(context, MenuActivity.class);
//Something else
context.startActivity(intent);
Go to your manifest file, you will for your MainActivity manifest:
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
Just copy them and paste them for your MenuActivity.
I had the same same problem than you and it worked for me, but I don't know why.
Good luck!
first make sure your AndroidManifest.xml file contain declaration of all Activities in your app, like
<activity android:name=".MenuActivity"/>
then you create new intent and start it where you need to start the second Activity
Intent intent = new Intent(v.getContext(), MenuActivity.class);
startActivity(intent);

android activity stack- back navigation

I am developing an app which has a home screen consisting of list view(Home Activity).User clicks on list item and new activity is started named as Topic.This activity also consist of list view. Home is set as parent activity for Topic.
Now in Topic class i am again calling Topic class using intent.
So a user clicks on a list item in Home activity,which opens a new Topic activity.User again clicks on list item ,and another new activity Topic is created,so we are at rd level. My app is working fine till here, but as Parent for Topic is Home,so as soon as i press back or up button,irrespective of where i am in my app,it is always the Home class which opens.
How to handle this so that all user can traverse back to each activity.
The code is given below:
Home.java
package com.example.guninder.home;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import java.util.List;
import static android.widget.AdapterView.*;
public class Home extends AppCompatActivity implements FetchDataListener {
private ProgressDialog dialog;
private ListView HomeListview;
private DrawerLayout home_drawer_layout;
private ListView Menu_option_list;
private String[] Menu_list;
private ActionBarDrawerToggle drawerToggle;
private ApplicationAdaptor adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
HomeListview = (ListView) findViewById(R.id.listView1);
itemClickListener(HomeListview);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
Menu_list = getResources().getStringArray(R.array.Menu_options);
home_drawer_layout = (DrawerLayout) findViewById(R.id.home_drawable);
Menu_option_list = (ListView) findViewById(R.id.home_menu_option);
Menu_option_list.setAdapter(new ArrayAdapter<>(this, android.R.layout.simple_expandable_list_item_1, Menu_list));
// home_Toolbar.setNavigationIcon(R.drawable.ic_drawer);
drawerToggle = new ActionBarDrawerToggle(this, home_drawer_layout, R.string.drawer_open, R.string.drawer_close) {
#Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
}
#Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
}
};
drawerToggle.setDrawerIndicatorEnabled(true);
home_drawer_layout.setDrawerListener(drawerToggle);
initView();
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_activity_actions, menu);
return true;
}
private void initView() {
// show progress dialog
dialog = ProgressDialog.show(this, "", "Loading...");
// String url = "http://dexterous.comuv.com/connect.php";
String url = "http://192.168.0.25/connect.php";
FetchDataTask task = new FetchDataTask(this);
task.execute(url,null);
}
#Override
public void onFetchComplete(List<Application> data) {
// dismiss the progress dialog
if (dialog != null) dialog.dismiss();
// create new adapter
adapter = new ApplicationAdaptor(this, data);
HomeListview.setAdapter(adapter);
// set the adapter to list
//setListAdapter(adapter);
}
public void onPostCreate(Bundle savedInstanceState){
super.onPostCreate(savedInstanceState);
drawerToggle.syncState();
}
#Override
public void onFetchFailure(String msg) {
// dismiss the progress dialog
if (dialog != null) dialog.dismiss();
// show failure message
Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
if(drawerToggle.onOptionsItemSelected(item)){
return true;
}
return super.onOptionsItemSelected(item);
}
public void itemClickListener(final ListView HomeListview) {
HomeListview.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Application app = adapter.getItem(position);
Intent intent = new Intent(Home.this, Topic.class);
intent.putExtra("topic_name",app.getTitle());
intent.putExtra("topic_id", app.getTopic_id());
intent.putExtra("Content", app.getParentContent());
Toast toast=Toast.makeText(Home.this,app.getParentContent(),Toast.LENGTH_LONG);
startActivity(intent);
}
});
}
}
Topic.java
package com.example.guninder.home;
import android.app.ProgressDialog;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.method.ScrollingMovementMethod;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
public class Topic extends AppCompatActivity implements FetchDataListener {
String topicName, ParentContent;
int topic_id;
//TextView txv;
ProgressDialog Topicdialog;
ListView topiclistView;
ApplicationAdaptor tAdaptor;
TextView txv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_topic);
Bundle extras = getIntent().getExtras();
if (extras == null) {
topicName = null;
}
topicName = extras.getString("topic_name");
topic_id = extras.getInt("topic_id");
ParentContent = extras.getString("Content");
txv = (TextView) findViewById(R.id.content);
txv.setMovementMethod(ScrollingMovementMethod.getInstance());
if (ParentContent.isEmpty()) {
txv.setVisibility(txv.GONE);
} else {
txv.setText(ParentContent);
}
setTitle(topicName);
topiclistView = (ListView) findViewById(R.id.topiclistView1);
itemClickListener(topiclistView);
topicinitView();
}
#Override
public void onPause(){
super.onPause();
}
public void onResume(){
super.onResume();
}
private void topicinitView() {
// show progress dialog
Topicdialog = ProgressDialog.show(this, "", "Loading...");
// String url = "http://dexterous.comuv.com/Topic.php";
String url = "http://192.168.0.25/Topic.php";
FetchDataTask task = new FetchDataTask(this);
task.execute(url, String.valueOf(topic_id));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_topic, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onFetchComplete(List<Application> data) {
if (Topicdialog != null) Topicdialog.dismiss();
// create new adapter
tAdaptor = new ApplicationAdaptor(this, data);
topiclistView.setAdapter(tAdaptor);
// set the adapter to list
//setListAdapter(adapter);
}
#Override
public void onFetchFailure(String msg) {
// dismiss the progress dialog
if (Topicdialog != null) Topicdialog.dismiss();
// show failure message
Toast.makeText(this, msg, Toast.LENGTH_LONG).show();
}
public void itemClickListener(final ListView TopicListview) {
TopicListview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Application app = tAdaptor.getItem(position);
if (app.getChildExist()) {
Intent intent = new Intent(Topic.this, Topic.class);
intent.putExtra("topic_name", app.getTitle());
intent.putExtra("topic_id", app.getTopic_id());
intent.putExtra("Content", app.getParentContent());
// Toast toast = Toast.makeText(Topic.this, app.getTopic_id(), Toast.LENGTH_LONG);
//toast.show();
startActivity(intent);
finish();
}
}
});
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.guninder.home" >
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".Home"
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=".Topic"
android:label="#string/title_activity_topic"
android:parentActivityName=".Home" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.guninder.home.Home" />
</activity>
<activity
android:name=".SetNotification"
android:label="#string/title_activity_set_notification"
android:theme="#android:style/Theme.Dialog" >
</activity>
</application>
</manifest>
Please help.Thanks in advance
Comment finish() inside the listitem click in topic class. it will solve your problem.
What you could do is, do not set Home as the parent of Topic.
This way when user presses back, the previous activity that was open will be shown to the user.

Android First App Error(Starting another activity)

I have a problem with loading another activity.I followed Tutorial When I click the button "Send", the application stops. Can anyone determine my error?
here is my MainActivity.java
package com.example.myfirstapp;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
public class MainActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
Intent intent = new Intent(MainActivity.this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,false);
return rootView;
}
}
}
here is my DisplayMeassageActivity.java:
public class DisplayMessageActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
setContentView(textView);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.display_message, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_display_message,
container, false);
return rootView;
}
}
}
here is my fragment_main.xml
<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"
android:orientation="horizontal"
tools:context="com.example.myfirstapp.MainActivity$PlaceholderFragment" >
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="sendMessage" />
</LinearLayout>
and AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.myfirstapp.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.example.myfirstapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.myfirstapp.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstapp.MainActivity" />
</activity>
</application>
</manifest>
Issue is with your DisplayMessageActivity onCreate.
You are trying to add the Fragment before the contentView is set.
Aslo your setContentView(textView) is setting only a TextView.
So, you need to remove the code adding a fragment or create a layout and set a ContentView before finding a View.

Clicking a Button and Opening a new Activity [duplicate]

This question already has an answer here:
Android adding new xml and class
(1 answer)
Closed 8 years ago.
This could be perceived as a silly question, but I am very new to Android.
I am making an app and I have added an info Activity, I have an info button on my main page and want to go to the info activity when I click it..
I'm actually not sure how to go about it.
this is the xml for the Button:
<Button
android:id="#+id/button2"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:background="#FFFFFF"
android:text="#string/info_btn" />
Do I add the code in the main activity, the intro activity or the xml?
This is my main activity
package ie.gmit.project;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void openSite(View v){
Uri uri = Uri.parse("http://gmitsu.ie/clubssocs/directory.html");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
UPDATED:
This has the updated code, and runs error free... but the button still will not go to the new activity when I run it.
package ie.gmit.project;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
private Button button2;//this is a bad name
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button2= (Button) findViewById(R.id.button2);//find the button
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), IntroActivity.class);
startActivity(i);
// finish();//if you want to close main activity after start info activity
}});
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.commit();
}
}
public void openSite(View v){
Uri uri = Uri.parse("http://gmitsu.ie/clubssocs/directory.html");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
return rootView;
}
}
}
Manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="ie.gmit.project"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="ie.gmit.project.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="ie.gmit.project.IntroActivity"
android:label="#string/title_activity_intro" >
</activity>
</application>
</manifest>
try this
public class MainActivity extends Activity {
private Button button2;//this is a bad name
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
button2= (Button) findViewById(R.id.button2);//find the button
button2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), InfoActivity.class);
startActivity(i);
finish();//if you want to close main activity after start info activity
});
}
declare in manifest intro activity in manifest
<activity
android:name=".IntroActivity"
android:label="Intro Activity"
android:theme="#android:style/Theme.Light.NoTitleBar.Fullscreen" >
</activity>
if this does not work you can add entries to the log to see if the data are assigning well, such as:
#Override
public void onClick(View v) {
Log.i("MyLog", "Im here!");
Intent i = new Intent(v.getContext(), InfoActivity.class);
startActivity(i);
finish();//if you want to close main activity after start info activity
});

not getting any response when clicking on send button in android app

I am an Android newbie and I was following this tutorial for learning android. The app takes input from the user and prints the text whenever the user presses the Submit button. It is able to take input from the user but it does not output anything when Submit button is pressed. Eclipse doesn't show any error in the code, so I don't know what's wrong. Here is the code(Sorry for pasting so much of code as I wasn't able to make out which file was exactly causing the error):
helloworld/src/com.archit.helloworld/DisplayMessageActivity.java
package com.archit.helloworld;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.archit.helloworld.R;
public class DisplayMessageActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_display_message);
// Show the Up button in the action bar.
setupActionBar();
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
//Create new text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
//set the text view as the activity layout
setContentView(textView);
}
/**
* Set up the {#link android.app.ActionBar}, if the API is available.
*/
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void setupActionBar() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() { }
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_display_message,
container, false);
return rootView;
}
}
}
helloworld/src/com.archit.helloworld/MainActivity.java
package com.archit.helloworld;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.helloworld.MESSAGE";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
}
}
helloworld/res/layout/activity_display_message.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"
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=".DisplayMessageActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
helloworld/res/layout/activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<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"
android:orientation="horizontal" >
<EditText android:id="#+id/edit_message"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:hint="#string/edit_message" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/button_send"
android:onClick="sendMessage" />
</LinearLayout>
helloworld/AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.archit.helloworld"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.archit.helloworld.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.archit.helloworld.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.helloworld.MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.helloworld.MainActivity" />
</activity>
</application>
</manifest>
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
}
has to be
/** Called when the user clicks the Send button */
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
Implement onclicklistener Where is your onclickListener
actually you forgot to add startActivity method
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
You have missed to call
startActivity(intent);
in your
sendMessage(View V)
method. So finally it will be
public void sendMessage(View view) {
// Do something in response to button
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}

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