Android 本地广播和强制下线功能的实现代码

package com.example.broadcasttest2;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
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;
private NetworkChangeReceiver networkChangeReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
intentFilter = new IntentFilter();
intentFilter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
networkChangeReceiver = new NetworkChangeReceiver();
registerReceiver(networkChangeReceiver,intentFilter);
localBroadcastManager = LocalBroadcastManager.getInstance(this);//获取实例
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
//下面这行代码是用来全局广播的
// Intent intent = new Intent("com.example.broadcasttest.MY_BROADCAST");
//下面这行代码是用来本地广播的（也就是app内部传递广播）
Intent intent = new Intent("com.example.broadcasttest.LOCAL_BROADCAST");
localBroadcastManager.sendBroadcast(intent);//发送本地广播 
// sendBroadcast(intent);
//我们关闭上面一行代码，然后写另一种方法sendOrderedBroadcast,发送有序广播
sendOrderedBroadcast(intent,null);
}
});
intentFilter = new IntentFilter();
intentFilter.addAction("com.example.broadcasttest.LOCAL_BROACAST");
localReceiver = new LocalReceiver();
localBroadcastManager.registerReceiver(localReceiver,intentFilter);//注册本地广播监听器
}
@Override
protected void onDestroy() {
super.onDestroy();
// unregisterReceiver(networkChangeReceiver);
localBroadcastManager.unregisterRecerver(localReceiver);
}
class NetworkChangeReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context,Intent intent) {
ConnectivityManager connectionMananger = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectionMananger.getActiveNetworkInfo();
if(networkInfo != null && networkInfo.isAvailable()) {
Toast.makeText(context, "network is available", Toast.LENGTH_SHORT).show(); 
} else {
Toast.makeText(context, "network is unavailable", Toast.LENGTH_SHORT).show();
}
}
}
class LocalReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context,Intent intent) {
Toast.makeText(context,"received local broadcast",Toast.LENGTH_SHORT).show();
}
}
}

package com.example.broadcastbestpractice;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
public class ActivityCollector {
public static List<Activity  activities = new ArrayList<Activity ();
public static void addActivity(Activity activity) {
activities.add(activity);
}
public static void removeActivity(Activity activity) {
activities.remove(activity);
}
public static void finishAll() {
for(Activity activity :activities) {
if(!activity.isFinishing()) {
activity.finish();
}
}
}
}

package com.example.broadcastbestpractice;
import android.app.Activity;
import android.os.Bundle;
public class BastActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ActivityCollector.addActivity(this);
}
@Override
public void onDestroy() {
super.onDestroy();
ActivityCollector.removeActivity(this);
}
}

<?xml version="1.0" encoding="utf-8"? 
<!-- 
android:shrinkColumns设置允许被收缩的列序号
android:strectColumns设置允许被拉伸的列序号 -- 
<TableLLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:strectColumns = "1"  
<TableRow 
<TextView
android:layout_height = "wrap_content"
android:text="Account:" / 
<EditText
android:id="@+id/account"
android:layout_height="wrap_content"
android:hint="Input your account" /   
</TableRow 
<TableRow 
<TextView
android:layout_height="wrap_content"
android:text="Password:" / 
<EditTest
android:id="@+id/password"
android:layout_height="wrap_content"
android:inputType="textPassword" /   
</TableRow 
<TableRow 
<Button
android:id="@+id/login"
android:layout_height="wrap_content"
android:layout_span="2"
android:text="Login" / 
</TableRow 
</TableLayout