I am following this tutorial: link text
Preferences.java:
public class Preferences extends PreferenceActivity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
}
}
PreferencesTutorial.java:
public class PreferencesTutorial extends Activity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button prefBtn = (Button) findViewById(R.id.prefButton);
prefBtn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent settingsActivity = new Intent(getBaseContext(),
Preferences.class);
startActivity(settingsActivity);
}
});
}
}
Preferences.xml:
When application starts, and i click the prefButton, an error occures: "The application PreferencesTutorial (process PreferencesTutorial.com.examples) has stopped unexpectedly. Please try again"
I haven't found any mistakes in the code.
I would also like to show my filestructure if that helps:
AndroidManifest.xml:
What is wrong with the code?
Even if i add (where the cursor is)
<activity
android:name=".Preferences"
android:label="#string/set_preferences">
</activity>
i still get the error.
Try removing this import, if you have it;
import java.util.prefs.Preferences;
You have to mention this in your androidManifest.xml file
<activity
android:name=".Preferences"
android:label="#string/set_preferences">
<intent-filter>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
</activity>
You probably do not have Preferences defined in your manifest.
However, as others have indicated, use adb logcat, DDMS, or the DDMS perspective in Eclipse to examine LogCat and see the stack trace associated with your crash.
Is the error raised in the OnClick in PreferencesTutorial Class or onCreate in the preferences Class? Stick a couple of Log.d("Debug","%ID") in various locations and see which one doesn't get called.
Related
I need to close an activity when a button is clicked. Unfortunately, when button is clicked, the activity does disappear but is still in the background. User can still select it and it comes back to front. What I need is the activity completely gone/destroyed.
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
finish();
}
});
}
#Override
protected void onDestroy() {
super.onDestroy();
}
}
I searched on SO on related questions, however, none of them help with closing the activity completely. I already tried adding return, adding another broadcast listener and passing command to call finish outside onCreate. So at this point, the question is - is this really possible or is this how Android works, you can call finish() but it is still in the background and user can re-launch it.
Here is xml file.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.app1.test.myapplication">
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
EDIT: Adding android:excludeFromRecents="true" does not solve the issue. Here are steps to recreate this, if anyone thinks it is a duplicate or already solved, please try and post comment/answer, I will accept it.
Open Android Studio
Create empty activity project.
Add a button.
Add code in MainActivity's onCreate for button click listener.
Inside click listener, call finish.
Run the app and click button and see if the activity is still in background or not.
Just give it a try.
In you manifest.
<activity
android:excludeFromRecents="true"
android:name=".Activities.SplashActivity"
android:theme="#style/AppThemeSubActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
Now in your java code.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.item_search:
// Intent intent = new Intent(MainActivity.this, SearchActivity.class);
// startActivity(intent);
finish();
System.exit(0);}
}
put the extra line System.exit(0); after calling finish it works for me.
You need to put this in your XML manifest:android:excludeFromRecents="true"
in your Activity TAG.
<activity
...
android:excludeFromRecents="true">
</activity>
You could try this
android:excludeFromRecents="true", Use it in your manifest.
plz try this to go back
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onBackPressed();
}
});
}
}
and this code to kill app process
moveTaskToBack(true);
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(1);
I'm trying to use SharedPreferencesBackupHelper to save my SharedPreferences value to cloud.
AndroidManifest.xml
<application
android:allowBackup="true"
android:backupAgent=".DataBackupAgent"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<meta-data android:name="com.google.android.backup.api_key" android:value="AEdPqrEAAAAIXMH86OqosQlXYuS0QbfyOaZT8fUadY1QUDzo2w" />
<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>
</application>
DataBackupAgent.java:
public class DataBackupAgent extends BackupAgentHelper {
public static final String PREFS = "data_prefs";
public static final String PREFS_BACKUP_KEY = "myprefs";
#Override
public void onCreate() {
SharedPreferencesBackupHelper helper = new SharedPreferencesBackupHelper(this, PREFS);
addHelper(PREFS_BACKUP_KEY, helper);
}
}
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
backupManager = new BackupManager(this);
prefs = getSharedPreferences(DataBackupAgent.PREFS, Context.MODE_PRIVATE);
edit = prefs.edit();
text = (EditText)findViewById(R.id.editText);
String value = prefs.getString(DataBackupAgent.PREFS_BACKUP_KEY,"");
text.setText(value);
Button btnBackup = (Button)findViewById(R.id.button);
btnBackup.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
edit.putString(DataBackupAgent.PREFS_BACKUP_KEY,text.getText().toString());
edit.commit();
backupManager.dataChanged();
}
});
}
My steps:
Write something at the EditText, click Backup button
Close app and open again. The saved value will be shown in EditText
Uninstall the app and reinstall again. The saved value is not shown in EditText at all.
Edit at 27/02/2015:
I added the following code to restore manually:
backupManager.requestRestore(new RestoreObserver() {
#Override
public void restoreFinished(int error) {
super.restoreFinished(error);
String value = prefs.getString(DataBackupAgent.PREFS_BACKUP_KEY,"");
text.setText(value);
}
#Override
public void restoreStarting(int numPackages) {
super.restoreStarting(numPackages);
}
#Override
public void onUpdate(int nowBeingRestored, String currentPackage) {
super.onUpdate(nowBeingRestored, currentPackage);
}
});
Unfortunately no callback functions are called.
This means back or auto restore doesn't work at all. Any idea? Thanks
My steps:
1. Write something at the EditText, click Backup button
2. Close app and open again. The saved value will be shown in EditText
3. Uninstall the app and reinstall again. The saved value is not shown in EditText at all.
To test your implementation there are others steps related to the use of bmgras we can see here.
Nevertheless I implemented this feature some days ago and following the steps in the documentation using a real device - Samsung SII - the automatic restore doesn't happen BUT using the emulator all was fine.
Logcat will show you all the operation output details.
IMO, the Android Data Backup feature is not reliable today. We can see some discussion about the implementation problems here and here.
Hope it helps!
When i try to redirect to next activity...
I am getting an error message stating as Source Not Found...
I am new to android development.
The following code is shows the activity which i need to redirect...
public class Disclaimer extends Activity {
Bundle bunUserInfo = null;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.disclaimer);
//Anyone plz help me.
Add The Disclaimer to AndroidManifest.xml file
<activity android:name=".Disclaimer"
android:theme="#android:style/Theme.NoTitleBar" >
</activity>
I'm new to Android Dev, so please help me out.
I'm trying to start a new activity after i press a button but nothing seems to work.
Here's my code:
public class viewInfo extends Activity {
private Button btn;
public TextView txt;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.info);
btn=(Button)findViewById(R.id.buy);
btn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
Intent myIntent = new Intent(viewInfo.this, buyNow.class);
startActivity(myIntent);
}
});
}
I've also added this new activity in the Manifest but it keeps crushing after I press the button.
What am I doing wrong?
Misread the question initially (original answer below for completeness sake).
Make sure you have the activity you are calling defined in your manifest file:
Something like
<activity android:name=".buyNow" android:label="#string/app_name"></activity>
within the application tags would suffice.
Here's the original answer.
Assuming that you have the correct button ID - try this in your onclick:
Intent myIntent = new Intent(getApplicationContext(), buyNow.class);
startActivity(myIntent);
You could add a log message inside your onClick too, to make sure it is actually being called. You can see the log from logcat (run via adb logcat on the command line)
Try to make it:
startActivity(new Intent("[Here is your package name.what you declared in Manifest file]"));
For this you need to write to your manifest:
Hope it helps.
There may be a problem with your buyNow activity that is causing the error.
You really need to use logcat to trace the error. You can enable this by clicking the menu item:
Window -> Show View -> Other...
the selecting "LogCat" from the Android folder
You can simply do this:
startActivity(new Intent(getBaseContext(),Activity.class));
Afther you registred your activity in manifest:
<activity
android:name="com.example.ActivityName"
android:label="#string/app_name" >
</activity>
in my app I am trying to add new screen. In my activity I've:
public void addItem(View v) {
Intent i = new Intent(SQLiteListActivity.this, add_screen.class);
startActivity(i);
}
In add_screen.java:
public class add_screen extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TextView tv = new TextView(this);
tv.setText("Hello, Android");
setContentView(tv);
}
}
In file add_screen.xml I've layout this screen. In file AndroidManifest.xml I added this next activity, especially:
<activity class=".Add_screen" android:name="ADD_ITEM" android:label="Add item">
</activity>
I am still getting an error message about "Application has been stopped." I am newbie in Android development, I tried to do this by some tutorial, I've everything by it, but I don't know why, I'm still getting the error message above...
Can you help me, please, with this problem? I've no idea, what could be wrong.
Try replacing the activity tag in your manifest with this instead:
<activity
android:name=".add_screen"
android:label="Add item"
>
<intent-filter>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
</activity>
You shouldn't need the class attribute, I don't even know if that's recognized.
Edit: Try the above instead?