广播服务

1. ActivityCollector.class 创建一类用于管理所有的活动

public class ActivityCollector {
    public static List<Activity> activities = new ArrayList<>();
    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();
             }
         }
    }
}

2.BaseActivity.class创建一个类作为所有活动的父类

public class BaseActivity extends AppCompatActivity {
    private  ForceOfflineReceiver receiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityCollector.addActivity(this);
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        ActivityCollector.removeActivity(this);
    }

    @Override
    protected void onResume() {
        super.onResume();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.sh.broadcasetbestpractice.FORCE_OFFLINE");
         receiver =  new ForceOfflineReceiver();
        registerReceiver(receiver,intentFilter);
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (receiver!=null)
        {
            unregisterReceiver(receiver);
            receiver=null;
        }
    }

    class  ForceOfflineReceiver extends BroadcastReceiver
    {
        @Override
        public void onReceive(final Context context, Intent intent) {
            AlertDialog.Builder  alertDialog = new AlertDialog.Builder(context);
            alertDialog.setTitle("Warning");
            alertDialog.setMessage("you are forced to be  offline,please try to login again");
            alertDialog.setCancelable(false);
            alertDialog.setPositiveButton("ok", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                     ActivityCollector.finishAll();//销毁所有的活动
                    Intent intent = new Intent(context,LoginActivity.class);
                    context.startActivity(intent);//启动登录活动

                }
            });
           alertDialog.show();
        }
    }
}

3.登录界面：activity_login.xml

 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/activity_login"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.sh.broadcasetbestpractice.LoginActivity">

     <LinearLayout
         android:orientation="horizontal"
         android:layout_width="match_parent"
         android:layout_height="60dp">
         <TextView
             android:layout_width="90dp"
             android:layout_height="wrap_content"
             android:layout_gravity="center_vertical"
             android:textSize="18sp"
             android:text="Account:"
             />
         <EditText
             android:id="@+id/account"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:layout_gravity="center_vertical"
             />
     </LinearLayout>

        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="60dp">
            <TextView
                android:layout_width="90dp"
                android:layout_height="wrap_content"
                android:layout_gravity="center_vertical"
                android:textSize="18sp"
                android:text="Password:"
                />
            <EditText
                android:id="@+id/password"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:layout_gravity="center_vertical"
                android:inputType="textPassword"
                />

        </LinearLayout>
        <Button
            android:id="@+id/login"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:text="Login"
            />

</LinearLayout>

4.LoninActivity.java 登录文件

  
public class LoginActivity extends BaseActivity {
    private EditText accountEdit;
    private EditText passwordEdit;
    private Button login;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        accountEdit=(EditText)findViewById(R.id.account);
        passwordEdit=(EditText)findViewById(R.id.password);
        login=(Button) findViewById(R.id.login);

        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String account = accountEdit.getText().toString();
                String password = passwordEdit.getText().toString();

                if (account.equals("admin") && password.equals("123456"))
                {

                    Intent intent = new Intent(LoginActivity.this,MainActivity.class);
                    startActivity(intent);
                    finish();
                }
                else
                {
                    Toast.makeText(LoginActivity.this,"account or password is invalid,pleaes try again", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}
5.activity_main.xml
   
<LinearLayout
    android:id="@+id/activity_main"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.sh.broadcasetbestpractice.MainActivity">

      <Button
          android:id="@+id/force_offline"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:text="send force offline broadcast"/>
</LinearLayout>
6.MainActivity.java
  
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 View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent("com.sh.broadcasetbestpractice.FORCE_OFFLINE");
//                Intent intent =  new Intent("com.sh.broadcasebestpractice.FORCE_OFFLINE");
                sendBroadcast(intent);
//                Toast.makeText(MainActivity.this, "display mainactivity information", Toast.LENGTH_SHORT).show();
            }
        });
    }
}
7.AndroidManifest.xml
  
<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.sh.broadcasetbestpractice"
          xmlns:android="http://schemas.android.com/apk/res/android">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
        </activity>
        <activity android:name=".LoginActivity">

            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>


    </application>

</manifest>