广播的最佳实践---实现强制下线功能

思路:只需要在界面上弹出一个对话框,让用户无法进行任何其他操作,必须点击对话框的确定按钮,然后登录到登录界面即可.

ActivityCollector.java
管理所有活动

package com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice;

import android.app.Activity;

import java.util.ArrayList;
import java.util.List;

/**
 * @author 王德强
 * 功能 : 管理所有的活动
 * 强制下线功能需要关闭所有的活动,然后回到登录界面
 */

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);
    }
    //关闭所有活动
    public static void finishAll(){
        for (Activity activity: activities) {
            if(!activity.isFinishing()){
                activity.finish();
            }
        }
    }
}

BaseActivity.java
作为所有活动的父类

package com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice;

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.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;

/**
 * Created by Deligence on 2017/5/24.
 * @author 王德强
 * 功能:作为所有活动的父类
 */

public class BaseActivity extends AppCompatActivity {
    //动态注册一个广播接收器
    private ForceOffLineReceiver receiver;
    @Override
    protected void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityCollector.addActivity(this);
    }

    //注册ForceOfflineReceiver广播接收器
    @Override
    protected void onResume() {
        super.onResume();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice.FORCE_OFFLINE");
        receiver = new ForceOffLineReceiver();
        registerReceiver(receiver,intentFilter);
    }

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

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


    private class ForceOffLineReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(final Context context, final Intent intent) {
            AlertDialog.Builder builder = new AlertDialog.Builder(context);
            builder.setTitle("Warning");
            builder.setMessage("You are forced to be offline,Please try to login again");
            builder.setCancelable(false);
            builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    ActivityCollector.finishAll();//销毁所有活动
                    Intent intent1 = new Intent(context,LoginActivity.class);
                    context.startActivity(intent1);//重启LoginActivity活动
                }
            });
            builder.show();
        }
    }
}

LoginActivity.java
登录模块

package com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.wangdeqiang.www.chatwithrobot.R;

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();
                //如果账户是admin密码是123456 则认为登陆成功
                if(account.equals("admin") && password.equals("123456")){
                    Intent intent = new Intent(LoginActivity.this,Main3Activity.class);
                    startActivity(intent);
                    finish();
                }else {
                    Toast.makeText(LoginActivity.this,"a account or a password is invalid",Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

activity_login.xml

<?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>

运行界面如下图所示

Main3Activity.java

package com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import com.wangdeqiang.www.chatwithrobot.R;

public class Main3Activity extends BaseActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        Button forceOffLine = (Button) findViewById(R.id.force_offonline);
        forceOffLine.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent("com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice.FORCE_OFFLINE");
                sendBroadcast(intent);
            }
        });
    }
}

activity_main3.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.wangdeqiang.www.chatwithrobot.BroadcastBestPractice.Main3Activity">
<Button
    android:id="@+id/force_offonline"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Send force offline broadcast"
    />
</android.support.constraint.ConstraintLayout>

运行图如图所示