OnTouchEvent：我想在屏幕上用另一根手指移动时识别触摸

Question

我正在尝试开发自己的游戏。但是我对 onTouchEvent-Method 有疑问。在显示我的代码之前很少解释。我希望能够用手指控制飞行。它应该总是跟随我的手指。为此，我实施了 MotionEvent.ACTION_MOVE 案例。航班只能在屏幕左侧移动。当我触摸屏幕右侧时，它应该会发射子弹。并且应该可以同时飞行和射击。这是我的代码：

public boolean onTouchEvent(MotionEvent event) {

    int maskedaction= event.getActionMasked();


        switch (maskedaction) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_POINTER_DOWN:
                    if (event.getX() > screenX / 2 && flight.toShoot == 0) {
                        flight.toShoot++;
                    }
                break;

            case MotionEvent.ACTION_MOVE: {
                    if (event.getX() < screenX / 2 - 100) {
                        flight.x = (int) event.getX() - 100;
                        flight.y = (int) event.getY() - 50;
                    }
                    break;

            }
        }

    return true;
}

这就是代码。当我触摸屏幕的左半部分时，我可以驾驶飞机飞来飞去。当我触摸右侧时，我可以射击。但我不能同时做。我想先触摸左半边然后飞来飞去。通过单击右侧，同时我将手指移动到左侧，它应该会发射子弹。

我发现当我用一根手指同时点击两侧时，飞机就会发射一发子弹。如果我现在松开右手指（触摸屏幕时发射的手指），我可以飞来飞去，当我飞来飞去的时候，我可以同时射击。

Answer 1

您可以通过检测 ID 来检测您的触摸，https://developer.android.com/training/gestures/multi

你可以这样做：

    int leftSideId = 0;
    int rightSideId = 1;

    public boolean onTouchEvent(MotionEvent event) {

        int maskedaction= event.getActionMasked();

        // Get the pointer ID
        int mActivePointerId = event.getPointerId(0);

        switch (maskedaction) {
            case MotionEvent.ACTION_DOWN:
            case MotionEvent.ACTION_POINTER_DOWN:

                if (event.getX() > screenX / 2) {
                    rightSideId = mActivePointerId;
                    if(flight.toShoot == 0){
                        flight.toShoot++;
                    }
                }else{
                    leftSideId = mActivePointerId;

                }
                break;

            case MotionEvent.ACTION_MOVE: {
                if (event.getX() < screenX / 2 - 100) {

                    if (mActivePointerId == leftSideId) {

                        flight.x = (int) event.getX() - 100;
                        flight.y = (int) event.getY() - 50;
                    }
                }
                break;

            }
        }

        return true;
    }

Answer 2

所以我自己找到了解决办法

public boolean onTouchEvent(MotionEvent event){

    int amount=event.getPointerCount();
    for (int i=0; i<amount; i++) {
            float x = event.getX(i);
            float y = event.getY(i);


        if (x>screenX/2 && flight.toShoot==0){
            flight.toShoot++;
        }

        if (x<screenX/2 -100 && flyingenabled)
        {
            flight.x = (int) x - 100;
            flight.y = (int) y - 50;
        }



    }
    return true;
}

这就是我的问题。比我想象的容易。

OnTouchEvent：我想在屏幕上用另一根手指移动时识别触摸

OnTouchEvent: I want to recognize touches while moving with an another finger on the screen

java

android

touch-event