我正在制作一个应用程序,当手机接到电话时会发生一些事情,因此经过大量搜索后,我发现我可以使用 BroadcastReceiver
和 Service
所以我创建了一个名为 PhoneStateService
的 Service
:
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.telephony.TelephonyManager;
import android.widget.Toast;
public class PhoneStateService extends Service {
private static BroadcastReceiver broadcastReceiver;
@Override
public IBinder onBind(Intent arg0) {
return null;
}
@Override
public void onCreate() {
registerBroadcastReceiver();
}
@Override
public void onDestroy() {
unregisterReceiver(broadcastReceiver);
broadcastReceiver = null;
}
private void registerBroadcastReceiver() {
broadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String stateStr = intent.getExtras().getString(TelephonyManager.EXTRA_STATE);
if(stateStr.equals(TelephonyManager.EXTRA_STATE_RINGING)){
new PhoneStateHandler().onIncomingCallStarted(context);
}
}
};
IntentFilter filter = new IntentFilter(TelephonyManager.ACTION_PHONE_STATE_CHANGED);
filter.addAction(Intent.ACTION_SCREEN_OFF);
registerReceiver(broadcastReceiver, filter);
}
}
这是启动PhoneStateService
的代码(在MainActivity
内):
if(PermissionChecker.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) == PermissionChecker.PERMISSION_GRANTED) {
startService(new Intent(getApplicationContext(), PhoneStateService.class));
}
来自 Manifest
文件的部分:
<service android:name=".Service.PhoneStateService" />
当手机接到电话并且应用程序正在运行(它仍然没有破坏)时,一切都工作正常,但是在我关闭应用程序并且手机接到电话后,应用程序崩溃并给我应用程序有的消息停止工作。
请告诉我问题是什么,我没有找到答案。
编辑:
异常(exception):
09-11 10:26:30.598 29461-29461/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.multiplies.multiring, PID: 29461
java.lang.RuntimeException: Error receiving broadcast Intent { act=android.intent.action.SCREEN_OFF flg=0x50000010 } in com.multiplies.multiring.Service.PhoneStateService$1@1924f18
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:891)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference
at com.multiplies.multiring.Service.PhoneStateService$1.onReceive(PhoneStateService.java:36)
at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:881)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
编辑:
我做了一些人说的:
String stateStr = intent.getExtras() != null ? intent.getExtras().getString(TelephonyManager.EXTRA_STATE) : "";
这样并不能解决问题。
我认为它不起作用,因为如果 intent.getExtras()
返回 null,那么 if 语句
将不起作用,因为它返回 null 并且需要 TelephonyManager.EXTRA_STATE_RINGING
:
if(stateStr.equals(TelephonyManager.EXTRA_STATE_RINGING)){
new PhoneStateHandler().onIncomingCallStarted(context);
}
但是谢谢你的帮助。
大量编辑:
list
的一部分:
<service android:name=".PhoneState.PhoneStateService" />
<receiver android:name=".PhoneState.PhoneStateBroadcast">
<intent-filter>
<action android:name="android.intent.action.PHONE_STATE" />
</intent-filter>
</receiver>
PhoneStateBroadcast
:
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.telephony.TelephonyManager;
import android.util.Log;
public class PhoneStateBroadcast extends BroadcastReceiver {
Context context;
public void onReceive(Context context, Intent intent) {
this.context = context;
try {
TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Service.TELEPHONY_SERVICE);
switch (telephonyManager.getCallState()) {
case TelephonyManager.CALL_STATE_RINGING:
context.startService(new Intent(context, PhoneStateService.class));
break;
}
} catch (Exception e) {
Log.e("Phone Receive Error", " " + e);
}
}
}
PhoneStateService
:
import android.app.IntentService;
import android.content.Intent;
public class PhoneStateService extends IntentService {
public PhoneStateService(String name) {
super(name);
}
@Override
protected void onHandleIntent(Intent intent) {
new PhoneStateHandler().onIncomingCallStarted(getApplicationContext());
}
}
经过此编辑,我仍然崩溃。
最佳答案
出于某种原因,额外的内容是空的。您正在执行 intent.getExtras().XXX
但 intent.getExtras()
返回 null,在其上调用 .XXX 会引发错误。
改变
String stateStr = intent.getExtras().getString(TelephonyManager.EXTRA_STATE);
进入
String stateStr = intent.getExtras() != null ? intent.getExtras().getString(TelephonyManager.EXTRA_STATE) : "";
将阻止崩溃的发生,但您可能想了解一下为什么您期望额外的内容,但 Intent 中却没有任何内容。
关于java - Android - 为什么当服务收到调用并且应用程序关闭时应用程序崩溃?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/46150593/