Android 悬浮窗全系统版本实现

悬浮窗是在系统上显示的内容，好像微信视频聊天时的小窗口一样，在退出软件后依然存在的一个窗口，本博客以窗口中放一个button组件为例，简单展示悬浮窗，其中包括了对Android 6.0以下、Android 6.0到Android 8.0、Android 8.0以上版本的处理，下面开始介绍实现方法：

1、MainActivity中的代码

public Button mFloatingButton;

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

        //初始化view
        initView();
    }
    //初始化view
    private void initView() {
        mFloatingButton=(Button) findViewById(R.id.floating_btn);
        mFloatingButton.setOnClickListener(this);
    }

    public void startFloatingButtonService(View view) {
        Log.e("测试流程", "测试流程");
        if (FloatingService_Button.isStarted) {
            Log.e("测试流程2", "测试流程2");
            return;
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//判断系统版本
            if (!Settings.canDrawOverlays(this)) {
                Toast.makeText(this, "当前无权限，请授权", Toast.LENGTH_SHORT);
                Log.e("测试流程3", "测试流程3");
                startActivityForResult(new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + getPackageName())), 0);
            } else {
                Log.e("测试流程4", "测试流程4");
                startService(new Intent(MainActivity.this, FloatingService_Button.class));
            }
        } else {
            startService(new Intent(MainActivity.this, FloatingService_Button.class));
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == 0) {
            if (!Settings.canDrawOverlays(this)) {
                Log.e("测试流程5", "测试流程5");
                Toast.makeText(this, "授权失败", Toast.LENGTH_SHORT).show();
            } else {
                Log.e("测试流程6", "测试流程6");
                Toast.makeText(this, "授权成功", Toast.LENGTH_SHORT).show();
                startService(new Intent(MainActivity.this, FloatingService_Button.class));
            }
        }
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.floating_btn :
                startFloatingButtonService(v);
                break;
        }
    }

思路简单解释：点击弹出悬浮窗按钮时，获取版本并判断“Build.VERSION.SDK_INT >= Build.VERSION_CODES.M”如果系统版本在6.0以下这不需要请求权限，如果系统版本在6.0以上需要进行权限检测以及请求，获取权限后，弹出悬浮框

2、activity_main.xml代码

简单解释：xml中没什么特别东西，线性布局中放一个按钮

3、FloatingService_Button的代码

public static boolean isStarted = false;

    private WindowManager windowManager;
    private WindowManager.LayoutParams layoutParams;

    private Button button;

    @Override
    public void onCreate() {
        super.onCreate();
        Log.e("进入服务1", "进入服务1");
        isStarted = true;
        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        layoutParams = new WindowManager.LayoutParams();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
        } else {
            layoutParams.type = WindowManager.LayoutParams.TYPE_PHONE;
        }
        layoutParams.format = PixelFormat.RGBA_8888;
        layoutParams.gravity = Gravity.LEFT | Gravity.TOP;
        layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
        layoutParams.width = 500;
        layoutParams.height = 100;
        layoutParams.x = 300;
        layoutParams.y = 300;
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.e("进入服务2", "进入服务2");

        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e("进入服务3", "进入服务3");
        showFloatingWindow();
        return super.onStartCommand(intent, flags, startId);
    }

    private void showFloatingWindow() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//判断系统版本
            if (Settings.canDrawOverlays(this)) {
                button = new Button(getApplicationContext());
                button.setText("我是个button窗口");
                button.setBackgroundColor(Color.BLUE);
                windowManager.addView(button, layoutParams);

                button.setOnTouchListener(new FloatingOnTouchListener());
            }
        } else {
            button = new Button(getApplicationContext());
            button.setText("我是个button窗口");
            button.setBackgroundColor(Color.BLUE);
            windowManager.addView(button, layoutParams);

            button.setOnTouchListener(new FloatingOnTouchListener());
        }
    }

    private class FloatingOnTouchListener implements View.OnTouchListener {
        private int x;
        private int y;

        @Override
        public boolean onTouch(View view, MotionEvent event) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    x = (int) event.getRawX();
                    y = (int) event.getRawY();
                    break;
                case MotionEvent.ACTION_MOVE:
                    int nowX = (int) event.getRawX();
                    int nowY = (int) event.getRawY();
                    int movedX = nowX - x;
                    int movedY = nowY - y;
                    x = nowX;
                    y = nowY;
                    layoutParams.x = layoutParams.x + movedX;
                    layoutParams.y = layoutParams.y + movedY;
                    windowManager.updateViewLayout(view, layoutParams);
                    break;
                default:
                    break;
            }
            return false;
        }
    }

思路简单解释：首先获取WindowManager服务，然后定义并设置在window上显示的layoutParams（此处需注意Android 8.0以上版本中LayoutParam里的type变量变为TYPE_APPLICATION_OVERLAY与Android 8.0以下版本LayoutParam里的type变量TYPE_PHONE不一样，需要通过判断系统版本进行区分），然后定义并设置在layoutParams上面显示的Button按钮以及监听事件（此处的监听事件主要是悬浮窗口拖动的监听）最后将设置好的button与layoutParams添加入window中

4、AndroidManifest.xml中权限添加

5、效果图

源码下载地址：Android悬浮窗 源码下载