package com.itheima74.broadcastbestpractice;import android.content.Intent;import android.os.Bundle;import android.os.SystemClock;import android.support.v4.content.LocalBroadcastManager;import android.view.View;/** * 模擬強制下線通知 * 1.登錄成功后10秒發送一條本地自定義無序廣播 * 2.接收到廣播后彈出對話框(不可取消) * 3.點擊對話框確定按鈕重新返回登陸界面 */public class MainActivity extends BaseActivity {  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    // 啟動一個子線程,10秒發送一條本地無序廣播    new Thread(new Runnable() {      @Override      public void run() {        SystemClock.sleep(1000 * 10);        LocalBroadcastManager localBroadcastManager = LocalBroadcastManager.getInstance(getApplicationContext());        localBroadcastManager.sendBroadcast(new Intent("com.itheima74.broadcastbestpractice.FORCE_OFFLINE"));      }    }).start();  }  // 點擊按鈕,啟動Main2Activity  public void click(View view) {    startActivity(new Intent(this, Main2Activity.class));  }}

package com.itheima74.broadcastbestpractice;import android.content.Intent;import android.os.Bundle;import android.support.annotation.Nullable;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.EditText;import android.widget.Toast;/** * Created by My on 2017/3/6. */public class LoginActivity extends AppCompatActivity {  private EditText et_username;  private EditText et_password;  @Override  protected void onCreate(@Nullable Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_login);    et_username = (EditText) findViewById(R.id.et_username);    et_password = (EditText) findViewById(R.id.et_password);  }  // 點擊按鈕,進行登錄  public void login(View view) {    String username = et_username.getText().toString().trim();    String password = et_password.getText().toString().trim();    if ("admin".equals(username) && "123456".equals(password)) {      Toast.makeText(this, "login success", Toast.LENGTH_SHORT).show();      startActivity(new Intent(this, MainActivity.class));    } else {      Toast.makeText(this, "login fail", Toast.LENGTH_SHORT).show();    }  }}

package com.itheima74.broadcastbestpractice;import android.app.AlertDialog;import android.content.BroadcastReceiver;import android.content.Context;import android.content.DialogInterface;import android.content.Intent;import android.content.IntentFilter;import android.os.Bundle;import android.support.annotation.Nullable;import android.support.v4.content.LocalBroadcastManager;import android.support.v7.app.AppCompatActivity;import android.util.Log;import java.util.ArrayList;/** * BaseActivity * 1.記錄所有新創建的Activity * 2.隨時銷毀所有Activity * 3.所有子類獲取焦點注冊廣播接收者,失去焦點取消注冊 * 4.收到強制下線廣播,彈出對話框,結束所有Activity,重新啟動LoginActivity * Created by My on 2017/3/6. */public class BaseActivity extends AppCompatActivity {  protected static ArrayList<BaseActivity> activityList = new ArrayList<>();  private LocalBroadcastManager localBroadcastManager;  private OffLineReceiver offLineReceiver;  private IntentFilter intentFilter;  @Override  protected void onCreate(@Nullable Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    activityList.add(this);    Log.d("china", getClass().getSimpleName() + " onCreate activityList.size():" + activityList.size());    localBroadcastManager = LocalBroadcastManager.getInstance(this);    offLineReceiver = new OffLineReceiver();    intentFilter = new IntentFilter("com.itheima74.broadcastbestpractice.FORCE_OFFLINE");  }  @Override  protected void onDestroy() {    super.onDestroy();    activityList.remove(this);    Log.d("china", getClass().getSimpleName() + " onDestroy activityList.size():" + activityList.size());  }  // 獲取焦點,注冊廣播接收者  @Override  protected void onResume() {    super.onResume();    localBroadcastManager.registerReceiver(offLineReceiver, intentFilter);  }  // 失去焦點,取消注冊廣播接收者  @Override  protected void onPause() {    super.onPause();    localBroadcastManager.unregisterReceiver(offLineReceiver);  }  protected class OffLineReceiver extends BroadcastReceiver {    @Override    public void onReceive(final Context context, Intent intent) {      // 彈出對話框      AlertDialog.Builder builder = new AlertDialog.Builder(BaseActivity.this);      builder.setTitle("Warning");      builder.setMessage("You are force to be offline,Please try to login again.");      builder.setCancelable(false);// 不允許back鍵取消      builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {        @Override        public void onClick(DialogInterface dialog, int which) {          BaseActivity.finishAll();          // 重新啟動LoginActivity,廣播接收者中需要添加任務棧          Intent intent = new Intent(context, LoginActivity.class);          intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);          context.startActivity(intent);        }      });      builder.show();    }  }  public static void finishAll() {    for (BaseActivity baseActivity : activityList) {      if (!baseActivity.isFinishing()) {        baseActivity.finish();      }    }  }}