每天进步一点-----全局大喇叭Broadcast

public class MainActivity extends BaseActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button forceOffline = (Button) findViewById(R.id.force_offline);
        forceOffline.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(
                        "com.example.broadcastbestpractice.FORCE_OFFLINE");
                sendBroadcast(intent);
            }
        });
    }

}

import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.view.WindowManager;

public class ForceOfflineReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, Intent intent) {
        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(context);
        dialogBuilder.setTitle("Warning");
        dialogBuilder.setMessage("You are forced to be offline. Please try to login again.");
        dialogBuilder.setCancelable(false);
        dialogBuilder.setPositiveButton("OK",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        ActivityCollector.finishAll();
                        Intent intent = new Intent(context, LoginActivity.class);
                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                        context.startActivity(intent);
                    }
                });
        AlertDialog alertDialog = dialogBuilder.create();
        alertDialog.getWindow().setType(
                WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        alertDialog.show();
    }

}

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 3     package="com.example.broadcastbestpractice"
 4     android:versionCode="1"
 5     android:versionName="1.0" >
 6 
 7     <uses-sdk
 8         android:minSdkVersion="14"
 9         android:targetSdkVersion="17" />
10 
11     <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
12 
13     <application
14         android:allowBackup="true"
15         android:icon="@drawable/ic_launcher"
16         android:label="@string/app_name"
17         android:theme="@style/AppTheme" >
18         <activity
19             android:name=".LoginActivity"
20             android:label="@string/app_name" >
21             <intent-filter>
22                 <action android:name="android.intent.action.MAIN" />
23 
24                 <category android:name="android.intent.category.LAUNCHER" />
25             </intent-filter>
26         </activity>
27         <activity android:name=".MainActivity" >
28         </activity>
29 
30         <receiver android:name=".ForceOfflineReceiver" >
31             <intent-filter>
32                 <action android:name="com.example.broadcastbestpractice.FORCE_OFFLINE" />
33             </intent-filter>
34         </receiver>
35     </application>
36 
37 </manifest>

package com.example.broadcasttest;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v4.content.LocalBroadcastManager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

    private IntentFilter intentFilter;

    private LocalReceiver localReceiver;

    private LocalBroadcastManager localBroadcastManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        localBroadcastManager = LocalBroadcastManager.getInstance(this);
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(
                        "com.example.broadcasttest.LOCAL_BROADCAST");
                localBroadcastManager.sendBroadcast(intent);
            }
        });
        intentFilter = new IntentFilter();
        intentFilter.addAction("com.example.broadcasttest.LOCAL_BROADCAST");
        localReceiver = new LocalReceiver();
        localBroadcastManager.registerReceiver(localReceiver, intentFilter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        localBroadcastManager.unregisterReceiver(localReceiver);
    }

    class LocalReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {
            Toast.makeText(context, "received local broadcast",
                    Toast.LENGTH_SHORT).show();
        }

    }

}