Question

我有一些在运行时创建并添加到FrameLayout的视图。视图可以移动onTouchEvent。到目前为止，我能够提出意见。但是，它们没有正常运转。我的意思是，第一次，当他们被移动时，他们一起移动。但是，当它们第二次移动时，手指和视图之间的距离会增加，并且它们会移动到手指指向之外的其他点。我没弄到错误的地方。以下是我的代码：

@Override
public boolean onTouch(View v, MotionEvent event) {
    final int X = (int) event.getRawX();
    final int Y = (int) event.getRawY();

    boolean result = v.onTouchEvent(event);
    switch (event.getAction() & MotionEventCompat.getActionMasked(event)) {
    case MotionEvent.ACTION_DOWN: {
        Log.e("CircleTest", "ACTION_DOWN");
        FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) v
                .getLayoutParams();

        deltaX = X - params.leftMargin;
        deltaY = Y - params.rightMargin;

        // Save the ID of this pointer
        mActivePointerId = event.getPointerId(0);
        break;
    }
    case MotionEvent.ACTION_UP:
        mActivePointerId = INVALID_POINTER_ID;
        break;
    case MotionEvent.ACTION_CANCEL:
        mActivePointerId = INVALID_POINTER_ID;
        break;
    case MotionEvent.ACTION_POINTER_DOWN:
        break;
    case MotionEvent.ACTION_POINTER_UP: {
        final int pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
        final int pointerId = event.getPointerId(pointerIndex);
        if (pointerId == mActivePointerId) {
            // This was our active pointer going up. Choose a new
            // active pointer and adjust accordingly.
            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastTouchX = event.getX(newPointerIndex);
            mLastTouchY = event.getY(newPointerIndex);
            mActivePointerId = event.getPointerId(newPointerIndex);
            break;
        }
    }
    case MotionEvent.ACTION_MOVE: {
        Log.e("CircleTest", "ACTION_MOVE");
        final int pointerIndex1 = event.findPointerIndex(mActivePointerId);
        final float x = event.getX(pointerIndex1);
        final float y = event.getY(pointerIndex1);

        final float dx = x - mLastTouchX;
        final float dy = y - mLastTouchY;

        mPosX += dx;
        mPosY += dy;

        FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) v
                .getLayoutParams();

        params.leftMargin = X - deltaX;
        params.topMargin = Y - deltaY;

        v.setLayoutParams(params);
        mLastTouchX = x;
        mLastTouchY = y;
        break;
    }
    default:
        return result;
    }
    main.invalidate();
    return false;
}

//**main** refers to the frame layout in which views are added.

Android：用手指移动视图

0 个答案: