BraodcastPractice

ActivityCollector:

package com.example.broadcastpractice;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(); } } }}

 BaseActivity:

package com.example.broadcastpractice;import android.app.Activity;import android.os.Bundle;public class BaseActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);ActivityCollector.addActivity(this);}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();ActivityCollector.removeActivity(this);}}

LoginActivity:

package com.example.broadcastpractice;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class LoginActivity extends BaseActivity {private EditText accountEdit;private EditText passwordEdit;private Button login;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.layout_login);accountEdit = (EditText) findViewById(R.id.account);passwordEdit = (EditText) findViewById(R.id.password);login = (Button) findViewById(R.id.login);login.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {String account = accountEdit.getText().toString();String password = passwordEdit.getText().toString();// 如果账号是admin且密码是123456，就认为登录成功if (account.equals("admin") && password.equals("123456")) {Intent intent = new Intent(LoginActivity.this,MainActivity.class);startActivity(intent);finish();} else {Toast.makeText(LoginActivity.this,"用户名或密码错误",Toast.LENGTH_SHORT).show();}}});}}

MainActivity:

package com.example.broadcastpractice;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity {private Button forceOffline;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        forceOffline = (Button) findViewById(R.id.force_offline);        forceOffline.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent intent = new Intent("FORCE_OFFLINE");//设置intent action sendBroadcast(intent);}});    }}

ForceOfflineReceiver:

package com.example.broadcastpractice.broadcast;import android.app.AlertDialog;import android.content.BroadcastReceiver;import android.content.Context;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.content.Intent;import android.view.WindowManager;import com.example.broadcastpractice.ActivityCollector;import com.example.broadcastpractice.LoginActivity;public class ForceOfflineReceiver extends BroadcastReceiver {@Overridepublic void onReceive(final Context context, Intent intent) {// TODO Auto-generated method stubAlertDialog.Builder builder = new AlertDialog.Builder(context);builder.setTitle("下线通知");builder.setMessage("您的账号已在别处登入,请重新登入");builder.setCancelable(false);builder.setPositiveButton("确定", new OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubActivityCollector.finishAll();Intent intent = new Intent(context, LoginActivity.class);intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);//重新创建一个新的Activitycontext.startActivity(intent); // 重新启动LoginActivity}});AlertDialog alertDialog = builder.create();alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);//需要把对话框的类型设为TYPE_SYSTEM_ALERT，不然它将无法在广播接收器里弹出。alertDialog.show();}}

    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
 <receiver android:name="com.example.broadcastpractice.broadcast.ForceOfflineReceiver" >
            <intent-filter>
                <action android:name="FORCE_OFFLINE" />
            </intent-filter>
        </receiver>