我正在创建一个应用程序，当手机接到电话时会发生一些事情，所以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{{ 1}}调用Service：
PhoneStateService这是启动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);
}
}
（PhoneStateService}内部的代码：
MainActivity部分来自if(PermissionChecker.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) == PermissionChecker.PERMISSION_GRANTED) {
startService(new Intent(getApplicationContext(), PhoneStateService.class));
}
文件：
Manifest当手机接到电话并且应用程序正在运行时（它仍然没有销毁）一切正常，但在我关闭应用程序并且手机接到电话后，应用程序崩溃并向我发送应用程序已有消息停止工作。
请告诉我有什么问题，我没有找到答案。编辑：
例外：
<service android:name=".Service.PhoneStateService" />
编辑：
我做了一些人说的话：
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)
把这个解决不了问题。
我认为它不起作用，因为如果String stateStr = intent.getExtras() != null ? intent.getExtras().getString(TelephonyManager.EXTRA_STATE) : "";
返回null，那么intent.getExtras()将无效，因为它返回null并且它需要if statement：
TelephonyManager.EXTRA_STATE_RINGING但是谢谢你的帮助。
巨大的编辑：
if(stateStr.equals(TelephonyManager.EXTRA_STATE_RINGING)){
new PhoneStateHandler().onIncomingCallStarted(context);
}
的一部分：
Manifest <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在编辑之后我仍然会崩溃。
答案 0 :(得分：2)
由于某种原因，额外的是空的。你正在做intent.getExtras().XXX但是intent.getExtras()返回null，在它上面调用.XXX会抛出错误。
更改
String stateStr = intent.getExtras().getString(TelephonyManager.EXTRA_STATE);
到
String stateStr = intent.getExtras() != null ? intent.getExtras().getString(TelephonyManager.EXTRA_STATE) : "";
会阻止崩溃的发生，但你可能想看看为什么你期望额外的原因是什么，但意图中没有。
答案 1 :(得分：2)
而不是运行服务总是把它变成一个BroadcastReciever，每当调用状态改变时就会触发它。（长时间运行服务不是一个好习惯）因此通过使用Broadcast接收器，你的服务会在你想要的时候运行。
public class PhoneStateService extends BroadcastReceiver{
public void onReceive(Context context, Intent intent) {
mContext = context;
try {
TelephonyManager tm = (TelephonyManager) context.getSystemService(Service.TELEPHONY_SERVICE);
String deviceId=tm.getDeviceId();
switch (tm.getCallState()) {
case TelephonyManager.CALL_STATE_RINGING: // incoming call
//do something on Incoming call event
break;
case TelephonyManager.CALL_STATE_IDLE: //call Ends
//do something on Idle phone state i.e set your logic if an incoming call is complete then this block would execute.
}
} catch (Exception e) {
Log.e("Phone Receive Error", " " + e);
}
}
}
然后将此broadcastReciever添加到应用程序标记
下的Manifest中 <receiver android:name="orbitsys.com.prospect_call.CallerState">
<intent-filter>
<action android:name="android.intent.action.PHONE_STATE" />
</intent-filter>