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Ich bin ein Android-Anfänger, so dass eine einfache Service Beispiel.getApplicationContext() Methode Fehler bekommen
aber in einem einzigen Code getApplicationContext() Methode verhält sich anders, Bitte überprüfen Sie den Kommentar von MainActivity.
MainActivity.java
package com.avisingh.servicetest;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button alertButton = (Button)findViewById(R.id.alert_btn);
alertButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this); //If i placing here getApplicationContext() method then getting error;
builder.setTitle("Warning");
builder.setMessage("Are you sure to open media played in this app?");
builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
startActivity(new Intent(getApplicationContext(),PlayerActivity.class)); // here getApplicationContext() and MainActivity.this both working
}
});
builder.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
AlertDialog alertDialog = builder.create();
alertDialog.show(); //getting error here.
}
});
}
}
PlayerActivity.java
package com.avisingh.servicetest;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
public class PlayerActivity extends AppCompatActivity{
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.player_activity);
final Button startBtn = (Button)findViewById(R.id.start_btn);
final Button stopBtn = (Button)findViewById(R.id.stop_btn);
startBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startService(new Intent(getApplicationContext(),MyServices.class));
}
});
stopBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
stopService(new Intent(getApplicationContext(),MyServices.class));
}
});
}
}
MyServices.java
package com.avisingh.servicetest;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.support.annotation.Nullable;
public class MyServices extends Service {
MediaPlayer mediaPlayer;
@Nullable
@Override
public IBinder onBind(Intent intent) {
//return null;
throw new UnsupportedOperationException("Not implemented");
}
@Override
public void onCreate() {
super.onCreate();
mediaPlayer = MediaPlayer.create(getApplicationContext(),R.raw.one_man);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
mediaPlayer.start();
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onDestroy() {
super.onDestroy();
mediaPlayer.stop();
}
}
AndroidManifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.avisingh.servicetest">
<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>
<activity android:name=".PlayerActivity"/>
<service android:name=".MyServices"/>
</application>
activity_main
<?xml version="1.0" encoding="utf-8"?>
<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"
tools:context="com.avisingh.servicetest.MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/alert_btn"
android:layout_centerHorizontal="true"
android:layout_marginTop="40dp"
android:id="@+id/alert_btn"/>
</RelativeLayout>
player_activity
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:text="@string/start_btn"
android:id="@+id/start_btn"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="50dp"
android:text="@string/stop_btn"
android:id="@+id/stop_btn"/>
</RelativeLayout>
Fehler:
08-14 14:17:58.916 6874-6874/com.avisingh.servicetest E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.avisingh.servicetest, PID: 6874
java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:359)
at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:328)
at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:289)
at android.support.v7.app.AppCompatDialog.setContentView(AppCompatDialog.java:83)
at android.support.v7.app.AlertController.installContent(AlertController.java:225)
at android.support.v7.app.AlertDialog.onCreate(AlertDialog.java:257)
at android.app.Dialog.dispatchOnCreate(Dialog.java:373)
at android.app.Dialog.show(Dialog.java:274)
at com.avisingh.servicetest.MainActivity$1.onClick(MainActivity.java:42)
at android.view.View.performClick(View.java:4759)
at android.view.View$PerformClick.run(View.java:19770)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5247)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:912)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:707)
Bitte posten Sie Ihre Datei styles.xml. – Ch4t4r