如何在拖动一个图像时停止其他图像移动

Question

在我的应用程序中，我能够一个接一个地重叠图像，当我从图像组中拖动一个图像时，左右图像也在屏幕上移动。如何限制这一点，下面是我的代码

    int cards[] = {R.drawable.c1,R.drawable.c2,R.drawable.c3,R.drawable.c4,R.drawable.c5,R.drawable.c6,
                R.drawable.c7,R.drawable.c8,R.drawable.c9,R.drawable.c10,R.drawable.c11,R.drawable.c12,R.drawable.c13};
    ImageView[] Images = new ImageView[cards.length];
            for (int i = 0; i < cards.length; i++) {           
                Images[i] = new ImageView(this);
                RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
                        RelativeLayout.LayoutParams.WRAP_CONTENT,
                        RelativeLayout.LayoutParams.WRAP_CONTENT);
                if (i != 0) {          
                     params.addRule(RelativeLayout.ALIGN_LEFT,i-1);
                     params.leftMargin= 40;
                     Images[i].setImageBitmap(BitmapFactory.decodeResource(getResources(), cards[i]));
                     Images[i].setId(i);
                     Images[i].setOnTouchListener(this);
                    layout.addView(Images[i], params);
                } else {
                     Images[i].setImageBitmap(BitmapFactory.decodeResource(getResources(), cards[i]));
                     Images[i].setId(i);
                     Images[i].setOnTouchListener(this);
                    layout.addView(Images[i], params);
                }
            }
//Ontouch
@Override
    public boolean onTouch(View p_v, MotionEvent p_event){
        params = (RelativeLayout.LayoutParams)p_v.getLayoutParams();
        switch (p_event.getAction()){       
        case MotionEvent.ACTION_DOWN:
        {
            status = START_DRAGGING;            
            imageView1 = new ImageView(this);
            imageView1.setImageBitmap(p_v.getDrawingCache());
            m_lastTouchX = p_event.getX();
            m_lastTouchY = p_event.getY();  
            break;
        }
        case MotionEvent.ACTION_UP:
        {
                status=STOP_DRAGGING;           
            break;
        }
        case MotionEvent.ACTION_MOVE:
        {
            if (status == START_DRAGGING) {
                m_dx = p_event.getX() - m_lastTouchX;
                m_dy = p_event.getY() - m_lastTouchY;
                m_posX = m_prevX + m_dx;
                m_posY = m_prevY + m_dy;
                System.out.println("Dragging");
                    params.leftMargin = (int) m_posX;
                    params.topMargin=(int) m_posY;
                    p_v.bringToFront();
                    p_v.setLayoutParams(params);
                    imageView1.invalidate();
                    m_prevX = m_posX;
                    m_prevY = m_posY;
            }

            break;
        }
        }
        return true;
    }

Answer 1

这里有一个小片段可以让你开始。我在RelativeLayout中添加了一些图像。绘图是在画布中完成的，以获得更好的拖动性能。您只需要处理布局参数更新MotionEvent.ACTION_UP事件：

private ImageView[] Images;
private boolean mDragging = false;
private Rect mImageRect = new Rect();
int mX = 0;
int mY = 0;
private Bitmap mBitmap;
private ImageView mImage;
@Override
public boolean onTouchEvent(MotionEvent ev) {
    switch (ev.getAction()) {
    case MotionEvent.ACTION_DOWN:
        mX = (int) ev.getX();
        mY = (int) ev.getY();
        for (ImageView image : Images) {
            image.getHitRect(mImageRect);
            if (mImageRect.contains(mX, mY)) {
                mDragging = true;
                mImage = image;
                mBitmap = ((BitmapDrawable) mImage.getDrawable())
                        .getBitmap();
                mImage.setVisibility(View.GONE);
                postInvalidate();
                break;
            }
        }
        break;
    case MotionEvent.ACTION_MOVE:
        if (mDragging) {
            mX = (int) ev.getX();
            mY = (int) ev.getY();
            postInvalidate();
        }
        break;
    case MotionEvent.ACTION_UP:
        if (mDragging) {
            mDragging = false;
            mBitmap = null;
            mImage.setVisibility(View.VISIBLE);
            mImage = null;
        }
        break;
    }
    return super.onTouchEvent(ev);
}
@Override
protected void dispatchDraw(Canvas canvas) {
    super.dispatchDraw(canvas);
    if (mBitmap != null) {
        canvas.drawBitmap(mBitmap, mX, mY, null);
    }
}

Answer 2

我的猜测是，由于您的图像重叠，所有三个图像都会获得onTouch事件并开始拖动。您应该添加一些逻辑来确定哪个图像是应该拖动的图像（例如，首先处理事件的图像），然后仅START_DRAGGING该图像。您已经具有"全局"值状态。旁边只需添加 int imageNo 并将其设置在 ACTION_DOWN case 语句中即可。

在主题上：您应该只处理ACTION_DOWN当状态 ！= START_DRAGGING。