WindowManager 悬浮窗口

要实现类似于 360 那样的悬浮框，可以使用 WindowManager 来实现

思路

我们再来理清下逻辑，我们需要当处于手机的普通界面，即桌面的时候，悬浮框才显示，而当启动其它 App 时，这个悬浮框应该消失不见,当我们退出 app 又回到桌面,这个悬浮框又要重新出现

我们需要使用一个定时器，每隔一段时间来进行一系列的判断，比如：是否在桌面，是否已加载悬浮框，否则加载；否则，如果加载了,就将这个悬浮框移除

实现

创建一个空的 Android 项目 cn.twle.android.FloatWindow

修改 activity_main.xml 添加一个按钮用户开启悬浮框

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp">

    <Button
        android:id="@+id/btn_on"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开启悬浮框" />

</RelativeLayout>

需要一个后台的 Service 在后台等待我们的操作，比如完成悬浮框的绘制移除等，

因此首先要定义一个 Service 实现一个创建悬浮框 View 的一个方法

MsMainServer.java

package cn.twle.android.floatwindow;;

import android.app.ActivityManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.PixelFormat;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;

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

public class MsMainService extends Service {

    private boolean isAdded = false; // 是否已增加悬浮窗
    public static final int OPERATION_SHOW = 100;
    public static final int OPERATION_HIDE = 101;
    private static final int HANDLE_CHECK_ACTIVITY = 200;
    public static final String OPERATION = "operation";
    private static WindowManager windowManager;
    private static WindowManager.LayoutParams params;
    private Button btnView;
    private ActivityManager mActivityManager;
    private List<String> homeList; // 桌面应用程序包名列表

    //定义一个更新界面的Handler
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case HANDLE_CHECK_ACTIVITY:
                    if (isHome()) {
                        if (!isAdded) {
                            windowManager.addView(btnView, params);
                            isAdded = true;
                            new Thread(new Runnable() {
                                public void run() {
                                    for (int i = 0; i < 10; i++) {
                                        try {
                                            Thread.sleep(1000);
                                        } catch (InterruptedException e) {
                                            e.printStackTrace();
                                        }
                                        Message m = new Message();
                                        m.what = 2;
                                        mHandler.sendMessage(m);
                                    }
                                }
                            }).start();
                        }
                    } else {
                        if (isAdded) {
                            windowManager.removeView(btnView);
                            isAdded = false;
                        }
                    }
                    mHandler.sendEmptyMessageDelayed(HANDLE_CHECK_ACTIVITY, 0);
                    break;
            }
        }
    };

    @Override
    public void onCreate() {
        super.onCreate();
        homeList = getHomes();
        createWindowView();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        int operation = intent.getIntExtra(OPERATION, OPERATION_SHOW);
        switch (operation) {
            case OPERATION_SHOW:
                mHandler.removeMessages(HANDLE_CHECK_ACTIVITY);
                mHandler.sendEmptyMessage(HANDLE_CHECK_ACTIVITY);
                break;
            case OPERATION_HIDE:
                mHandler.removeMessages(HANDLE_CHECK_ACTIVITY);
                break;
        }
        return super.onStartCommand(intent, flags, startId);
    }

    // 定义一个创建悬浮框的方法:
    private void createWindowView() {
        btnView = new Button(getApplicationContext());
        btnView.setBackgroundResource(R.mipmap.ic_launcher);
        windowManager = (WindowManager) getApplicationContext()
                .getSystemService(Context.WINDOW_SERVICE);
        params = new WindowManager.LayoutParams();

        // 设置Window Type
        params.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
        // 设置悬浮框不可触摸
        params.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
        // 悬浮窗不可触摸，不接受任何事件,同时不影响后面的事件响应
        params.format = PixelFormat.RGBA_8888;
        // 设置悬浮框的宽高
        params.width = 200;
        params.height = 200;
        params.gravity = Gravity.LEFT;
        params.x = 200;
        params.y = 000;
        // 设置悬浮框的Touch监听
        btnView.setOnTouchListener(new View.OnTouchListener() {
            //保存悬浮框最后位置的变量
            int lastX, lastY;
            int paramX, paramY;

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        lastX = (int) event.getRawX();
                        lastY = (int) event.getRawY();
                        paramX = params.x;
                        paramY = params.y;
                        break;
                    case MotionEvent.ACTION_MOVE:
                        int dx = (int) event.getRawX() - lastX;
                        int dy = (int) event.getRawY() - lastY;
                        params.x = paramX + dx;
                        params.y = paramY + dy;
                        // 更新悬浮窗位置
                        windowManager.updateViewLayout(btnView, params);
                        break;
                }
                return true;
            }
        });
        windowManager.addView(btnView, params);
        isAdded = true;
    }

    /**
     * 判断当前界面是否是桌面
     */
    public boolean isHome() {
        if (mActivityManager == null) {
            mActivityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
        }
        List<ActivityManager.RunningTaskInfo> rti = mActivityManager.getRunningTasks(1);
        return homeList.contains(rti.get(0).topActivity.getPackageName());
    }

    /**
     * 获得属于桌面的应用的应用包名称
     *
     * @return 返回包含所有包名的字符串列表
     */
    private List<String> getHomes() {
        List<String> names = new ArrayList<String>();
        PackageManager packageManager = this.getPackageManager();
        // 属性
        Intent intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_HOME);
        List<ResolveInfo> resolveInfo = packageManager.queryIntentActivities(intent,
                PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo ri : resolveInfo) {
            names.add(ri.activityInfo.packageName);
        }
        return names;
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

修改 Activity_main.xml 添加权限和注册服务

添加权限

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<uses-permission android:name="android.permission.GET_TASKS" />

注册服务

<service android:name=".MsMainService"/>

修改 MainActivity.java 启动 Service

package cn.twle.android.floatwindow;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_on;

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

    private void bindViews() {
        btn_on = (Button) findViewById(R.id.btn_on);
        btn_on.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_on:
                Intent mIntent = new Intent(MainActivity.this, MsMainService.class);
                mIntent.putExtra(MsMainService.OPERATION, MsMainService.OPERATION_SHOW);
                startService(mIntent);
                Toast.makeText(MainActivity.this, "悬浮框已开启~", Toast.LENGTH_SHORT).show();
                break;
        }
    }
}

简单教程

思路

实现

参考文档

Android 基础教程