安卓开发实现强制下线功能

项目结构

ActivityCollector

BaseActivity

LoginActivity

MainActivity

activity_login.xml?

activity_main.xml

运行截图

ActivityCollector

public class ActivityCollector {
    // 创建一个静态的Activity列表，用于存储所有的Activity实例
    public static List<Activity> activities = new ArrayList<>();

    // 添加Activity实例到列表中
    public static void addActivity(Activity activity){
        activities.add(activity);
    }

    // 从列表中移除指定的Activity实例
    public static void removeActivity(Activity activity){
        activities.remove(activity);
    }

    // 结束所有存储在列表中的Activity实例
    public static void finishAll(){
        for (Activity activity:activities){
            activity.finish();
        }
    }
}

BaseActivity

public class BaseActivity extends AppCompatActivity {
    private ForceOfflineReceiver receiver;

    // 在Activity创建时将其添加到ActivityCollector的活动列表中
    protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        ActivityCollector.addActivity(this);
    }

    // 在Activity恢复时注册ForceOfflineReceiver广播接收器
    protected void onResume(){
        super.onResume();
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.example.OFF"); // 指定广播的Action
        receiver = new ForceOfflineReceiver();
        registerReceiver(receiver, intentFilter);
    }

    // 在Activity暂停时注销ForceOfflineReceiver广播接收器
    protected void onPause(){
        super.onPause();
        if(receiver != null){
            unregisterReceiver(receiver);
            receiver = null;
        }
    }

    // 在Activity销毁时从ActivityCollector的活动列表中移除该活动
    protected void onDestroy(){
        super.onDestroy();
        ActivityCollector.removeActivity(this);
    }

    // 内部类，继承自BroadcastReceiver用于接收ForceOffline广播
    class ForceOfflineReceiver extends BroadcastReceiver{

        @Override
        public void onReceive(Context context, Intent intent) {
            // 创建一个弹窗对话框，显示禁止登录的提示信息
            AlertDialog.Builder builder =new AlertDialog.Builder(context);
            builder.setTitle("禁止登陆");
            builder.setMessage("您的账号已在另一台设备登陆、请重新登录");
            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 intent = new Intent(context, LoginActivity.class);
                    context.startActivity(intent); // 重启登录页
                }
            });
            builder.show();
        }
    }
}

LoginActivity

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);

        // 获取布局中的控件实例
        accountEdit = (EditText) findViewById(R.id.accountEdit);
        passwordEdit = (EditText) findViewById(R.id.passwordEdit);
        login = (Button) findViewById(R.id.login);

        // 设置按钮的点击事件监听器
        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String user = accountEdit.getText().toString();
                String paw  = passwordEdit.getText().toString();

                // 检查用户输入的账号和密码
                if (user.equals("admin") && paw.equals("123")) {
                    // 账号密码正确，跳转到MainActivity
                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);
                    startActivity(intent);
                    finish();
                } else {
                    // 账号密码错误，显示错误提示信息
                    Toast.makeText(LoginActivity.this, "账户或密码错误", Toast.LENGTH_SHORT).show();
                }
            }
        });
    }
}

MainActivity

public class MainActivity extends BaseActivity {

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

        // 获取布局中的按钮实例
        Button offView = (Button) findViewById(R.id.but_off);

        // 为按钮设置点击事件监听器
        offView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 创建一个意图并指定广播的Action为"com.example.OFF"
                Intent intent = new Intent("com.example.OFF");

                // 发送广播
                sendBroadcast(intent);
            }
        });
    }
}

activity_login.xml?

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".LoginActivity">
    
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="账户:"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintHorizontal_bias="0.1"
        app:layout_constraintVertical_bias="0.3"/>
    <EditText
        android:id="@+id/accountEdit"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintVertical_bias="0.3"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/textView1"
        app:layout_constraintTop_toTopOf="parent"/>
    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="密码:"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintHorizontal_bias="0.1"
        app:layout_constraintVertical_bias="0.4"/>
    <EditText
        android:id="@+id/passwordEdit"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintVertical_bias="0.4"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/textView2"
        app:layout_constraintTop_toTopOf="parent"/>
    <Button
        android:id="@+id/login"
        android:text="login"
        android:layout_width="222dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".MainActivity">
    
    <Button
        android:id="@+id/but_off"
        android:layout_width="222dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        android:text="强制下线"/>

</androidx.constraintlayout.widget.ConstraintLayout>