android 多屏異屏顯

作業組要對車機做成套軟體，三個螢屏，儀表，中控和副駕駛螢屏，軟體跨螢屏呼叫有音樂，視頻，副螢屏底部懸浮窗控制欄，視頻用到了三指飛屏，現在主要分享一下用到的代碼和使用范圍，

視頻三指飛屏

	1.自定義viewgroup監聽viewGroup的touchevent，

下面展示一些 `行內代碼片`，

// 攔截判斷觸控點數
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        pointerCount = Math.max(ev.getPointerCount(), pointerCount);

        if (pointerCount >= POINT_COUNT){
            actionDownX = ev.getX();
            return true;
        }else {
            return false;
        }
    }

	2攔截之后監聽滑動操作

// 判斷滑動距離和方向

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        pointerCount = event.getPointerCount();

        if (pointerCount >= POINT_COUNT){

            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    Objects.requireNonNull(callback).onPressAction(true);
                    break;
                case MotionEvent.ACTION_POINTER_UP:
                    if (event.getPointerCount() == POINT_COUNT) {
                        actionUpX = event.getX();
                        Log.e(TAG, "onTouchEvent: action up-----------" + actionUpX);
                        adjusScrollDirection();
                    }
                    break;
            }
//        gestureDetector.onTouchEvent(event);

            return false;
        }else {
            return false;
        }
    }

activity 切換副螢屏，

// 跳轉副螢屏
    public void newSecondActivity(int windowIndex) {
        saveVideoProgress();
        CurrentActivity = 1;
        finish();
        isChangeScreen = true;
        Intent in = new Intent(this, SecondActivity.class);
        ActivityOptions options = ActivityOptions.makeBasic();
        in.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        options.setLaunchDisplayId(displays[windowIndex].getDisplayId());

        startActivity(in, options.toBundle());
    }

一個activity在另一個螢屏打開activity，需要傳入options的launchdisplayid，同時要設定intent的flag為Intent.FLAG_ACTIVITY_NEW_TASK

service中打開異屏懸浮窗

1.service打開懸浮窗這個就很有意思了，不像activity，有ActivityOptions，直接貼代碼

// 創建布局

    public void toSecondScreen() {

        DisplayManager mDisplayManager = (DisplayManager) this.getSystemService(Context.DISPLAY_SERVICE);
        ;//螢屏管理類
        Display[] displays = mDisplayManager.getDisplays(); //得到顯示幕陣列;//螢屏陣列
        Display secondDisplay = displays[1];
        Context secondDisplayContext = createDisplayContext(secondDisplay);

        mWindowManager = (WindowManager) secondDisplayContext.getSystemService(WINDOW_SERVICE);
        mLayoutParams = new WindowManager.LayoutParams();
        mLayoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
//        mLayoutParams.type = WindowManager.LayoutParams.TYPE_TOAST;
        mLayoutParams.format = PixelFormat.RGBA_8888;
        mLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
        mLayoutParams.gravity = Gravity.LEFT | Gravity.TOP;
        mLayoutParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
        mLayoutParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
        mLayoutParams.x = 0;
        mLayoutParams.y = 0;


        cuslayout = new CustomContentLinearlayout(secondDisplayContext);

        showLayout();
    }



    private void showLayout() {

        if (isShow) {
            Toast.makeText(this, "已經顯示", Toast.LENGTH_SHORT).show();
        }

        if (cuslayout != null) {
            mWindowManager.addView(cuslayout, mLayoutParams);
            isShow = true;
        }

    }

跟activity不同的是要 Context secondDisplayContext = createDisplayContext(secondDisplay);
創建一個displaycontex，然后才能設定螢屏id

遺留問題

1.0螢屏打開a后再關閉，1螢屏再打開a，仍然會出現在0螢屏，問題是出現在底層，video當時用的是a，b兩個activity，實作雙入口實作的，但只能治標不治本，