广播，实现强制下线功能（项目文件已上传GitHub）

项目文件GitHub地址：

https://github.com/Skymqq/BroadcastBestPractice.git

 

新建BoradcastBestPractice项目。

首先我们需要制作一个登录界面，并且定义它为第一个显示的界面。

新建LoginActivity.java，代码如下：

package com.example.administrator.broadcastbestpractice;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.View;
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;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        initializeView();
    }

    private void initializeView() {
        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 of password is invalid", Toast.LENGTH_SHORT).show();
                }

            }
        });
    }



}

activity_login.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="Account:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/account"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1" />

    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:orientation="horizontal">

        <TextView
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:text="Password:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/password"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1"
            android:inputType="textPassword" />

    </LinearLayout>

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

</LinearLayout>

然后再将AndroidManifest.xml中的代码改一下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.administrator.broadcastbestpractice">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".LoginActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

MainActivity.java代码：

package com.example.administrator.broadcastbestpractice;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentFilter;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends BaseActivity {

    private ForceOfflineBroadcast receiver;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ActivityCollector.addActivity(this);

        Button forceOffline=(Button)findViewById(R.id.force_offline);
        forceOffline.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent("com.example.broadcastbestpractice.FORCE_OFFLINE");
                sendBroadcast(intent);
            }
        });
    }


    @Override
    protected void onResume() {
        super.onResume();

        IntentFilter intentFilter=new IntentFilter();
        intentFilter.addAction("com.example.broadcastbestpractice.FORCE_OFFLINE");
        receiver=new ForceOfflineBroadcast();
        registerReceiver(receiver,intentFilter);
    }


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

    }

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


    private class ForceOfflineBroadcast extends BroadcastReceiver {
        @Override
        public void onReceive(final Context context, final Intent intent) {
            AlertDialog.Builder builder=new AlertDialog.Builder(context);
            builder.setTitle("Warning")
                    .setMessage("You are forced to be offline. Please try to login again.")
                    .setCancelable(false)
                    .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            ActivityCollector.finishAll();//销毁所有活动
                            Intent intent=new Intent(context,LoginActivity.class);
                            context.startActivity(intent);
                        }
                    }).show();

        }
    }
}

activity_main.xml代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/force_offline"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Send Force offline broadcast"
        android:textAllCaps="false" />
</LinearLayout>

运行程序，（用户名：admin  密码：123456）效果图：

登录成功，进入MainActivity活动

在MainActivity活动中点击btn按钮弹出对话框提示

点击OK，强制下线，又回到了登录界面。