如何在切换小部件打开时阻止来电？

我有一个应用程序，其中放置了一个开关切换按钮。我的应用程序的目的是，只要开关按钮设置为ON，所有来电都应该被阻止。我可以阻止所有呼叫，但当开关设置为ON时，我无法阻止。如何在切换小部件打开时阻止来电？

我创建了一个名为MyClassReceiver的类来扩展Broadcast Receiver，所有的呼叫阻塞都在这个类中完成。我在Manifest文件中添加了完美工作的接收器代码。

这是我使用的代码： -

MainActivity.java

package com.chinmay.smsender; 

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.media.AudioManager; 
import android.os.Bundle; 
import android.view.Menu; 
import android.widget.CompoundButton; 
import android.widget.CompoundButton.OnCheckedChangeListener; 
import android.widget.Switch; 

public class MainActivity extends Activity { 

public Switch mySwitch; 
//private LinearLayout bgElement; 
private AudioManager mAudio; 
boolean switchChecked; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    mySwitch = (Switch) findViewById(R.id.switch1); 
    //bgElement = (LinearLayout) findViewById(R.id.container); 
    mAudio = (AudioManager) getBaseContext().getSystemService(Context.AUDIO_SERVICE); 

    mySwitch.setOnCheckedChangeListener(new OnCheckedChangeListener(){ 

     @Override 
     public void onCheckedChanged(CompoundButton arg0, boolean isChecked) { 
      if(isChecked) { 
       mAudio.setRingerMode(AudioManager.RINGER_MODE_SILENT); 
       broadcastIntent(true); 
       //bgElement.setBackgroundColor(Color.GREEN); 
      } else { 
       mAudio.setRingerMode(AudioManager.RINGER_MODE_NORMAL); 
       broadcastIntent(false); 
       //bgElement.setBackgroundColor(Color.RED); 
      } 
     } 

    }); 
} 

public void broadcastIntent(boolean isChecked) { 
    Intent intent = new Intent(); 
    intent.setAction("com.chinmay.CUSTOM_INTENT"); 
    intent.putExtra("switchChecked", isChecked); 
    sendBroadcast(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; 
} 

}

MyClassReceiver.java

package com.chinmay.smsender; 

import java.lang.reflect.Method; 

import com.android.internal.telephony.ITelephony; 

import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 
import android.telephony.TelephonyManager; 
import android.widget.Toast; 


public class MyClassReceiver extends BroadcastReceiver { 
private ITelephony telephonyService; 
Context context = null; 
boolean isChecked; 

@Override 
public void onReceive(Context context, Intent intent) { 

    TelephonyManager telephony = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); 

    isChecked = intent.getExtras().getBoolean("switchChecked"); 

    if(isChecked) { 
     Toast.makeText(context, "Blocking calls", Toast.LENGTH_LONG).show(); 

     if(intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(TelephonyManager.EXTRA_STATE_RINGING)) { 
      //String incomingNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER); 
      //Toast.makeText(context, "Call from: "+incomingNumber, Toast.LENGTH_LONG).show(); 

      try { 
        Class<?> c = Class.forName(telephony.getClass().getName()); 
        Method m = c.getDeclaredMethod("getITelephony"); 
        m.setAccessible(true); 
        telephonyService = (ITelephony) m.invoke(telephony); 
        //telephonyService.silenceRinger(); 
        telephonyService.endCall(); 
      } catch (Exception e) { 
        e.printStackTrace(); 
      } 

     } 
    } else if(isChecked == false) { 
     Toast.makeText(context, "Blocking calls off", Toast.LENGTH_LONG).show(); 
    } 

    /* else if(intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(TelephonyManager.EXTRA_STATE_IDLE) || intent.getStringExtra(TelephonyManager.EXTRA_STATE).equals(TelephonyManager.EXTRA_STATE_OFFHOOK)) { 
     Toast.makeText(context, "Detected Call Hangup Event.", Toast.LENGTH_LONG).show(); 
    }*/ 
} 

}

Android清单

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.chinmay.smsender" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk 
    android:minSdkVersion="14" 
    android:targetSdkVersion="19" /> 

<uses-permission android:name="android.permission.READ_PHONE_STATE" /> 
<uses-permission android:name="android.permission.CALL_PHONE" /> 

<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name="com.chinmay.smsender.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> 

    <receiver android:name="com.chinmay.smsender.MyClassReceiver"> 
     <intent-filter> 
      <action android:name="android.intent.action.PHONE_STATE" /> 
      <action android:name="com.chinmay.CUSTOM_INTENT" /> 
     </intent-filter> 
    </receiver>  
</application> 

</manifest>

这是错误我明白了如果我运行此代码

10-31 13:03:26.283: E/AndroidRuntime(759): FATAL EXCEPTION: main 
10-31 13:03:26.283: E/AndroidRuntime(759): Process: com.chinmay.smsender, PID: 759 
10-31 13:03:26.283: E/AndroidRuntime(759): java.lang.RuntimeException: Unable to start receiver com.chinmay.smsender.MyClassReceiver: java.lang.NullPointerException 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2441) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.app.ActivityThread.access$1700(ActivityThread.java:139) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1286) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.os.Handler.dispatchMessage(Handler.java:102) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.os.Looper.loop(Looper.java:136) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.app.ActivityThread.main(ActivityThread.java:5086) 
10-31 13:03:26.283: E/AndroidRuntime(759): at java.lang.reflect.Method.invokeNative(Native Method) 
10-31 13:03:26.283: E/AndroidRuntime(759): at java.lang.reflect.Method.invoke(Method.java:515) 
10-31 13:03:26.283: E/AndroidRuntime(759): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
10-31 13:03:26.283: E/AndroidRuntime(759): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
10-31 13:03:26.283: E/AndroidRuntime(759): at dalvik.system.NativeStart.main(Native Method) 
10-31 13:03:26.283: E/AndroidRuntime(759): Caused by: java.lang.NullPointerException 
10-31 13:03:26.283: E/AndroidRuntime(759): at com.chinmay.smsender.MyClassReceiver.onReceive(MyClassReceiver.java:49) 
10-31 13:03:26.283: E/AndroidRuntime(759): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2434) 
10-31 13:03:26.283: E/AndroidRuntime(759): ... 10 more

我认为，因为我发送2个意向MyClassReceiver，我得到此错误。

请告诉我如何才能知道MyClassReceiver本身中的切换按钮的状态，并在开关打开时阻止每个呼叫。

来源

2014-10-31 Chinmay Sarupria

您正在初始化context中的类= null。只是在课堂上宣布它，并在接收方法初始化它可能工作.. – 2014-10-31 11:49:43

@ MSGadag我已经尝试过它，它不起作用。 – 2014-10-31 12:08:37

insted contex，在Toast中使用classname.this ... – 2014-10-31 12:10:50