Question

我正在使用非常标准的拖放实现，以便拖动图钉并将其放置在图像视图的顶部以指向图像的特定部分：

@Override
    public boolean onDrag(View v, DragEvent event) {
        int action = event.getAction();
        switch (event.getAction()) {
            case DragEvent.ACTION_DRAG_STARTED:
                break;
            case DragEvent.ACTION_DRAG_ENTERED:
                break;
            case DragEvent.ACTION_DRAG_EXITED:
                break;
            case DragEvent.ACTION_DROP:
                View view = (View) event.getLocalState();
                ViewGroup owner = (ViewGroup) view.getParent();
                owner.removeView(view);
                FrameLayout container = (FrameLayout) v;
                container.addView(view);
                FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.WRAP_CONTENT, FrameLayout.LayoutParams.WRAP_CONTENT);

                int a = Math.round((event.getX() - (view.getWidth() / 2)));
                int b = Math.round((event.getY() - (view.getHeight() / 2)));

                lp.setMargins(a,b,0,0);
                view.setLayoutParams(lp);
                view.setVisibility(View.VISIBLE);

                //Gets actual pixel location on image - currently unused
                float[] point = new float[] {event.getX(), event.getY()};
                Matrix inverse = new Matrix();
                iv.getImageMatrix().invert(inverse);
                inverse.mapPoints(point);
                float density = getResources().getDisplayMetrics().density;
                point[0] /= density;
                point[1] /= density;
                break;
            case DragEvent.ACTION_DRAG_ENDED:
                break;
            default:
                break;
        }

图像视图是一个可缩放的图像视图（chrisbanes / PhotoView），如果图像保持在通常的100％比例，则坐标全部正常工作并且标记正确放置。但是，如果我放大图像，将标记放在特定的位置以进行更精细的控制，而在缩小标记时获得正确的坐标不会保持在相对于图像的相同位置。只是父母的。请让我知道您希望看到的代码（没有其他内容）或者我是否需要重新解释

由于

Answer 1

我做了一个应用程序，用户可以触摸移动视图，也可以缩放。

在我的情况下，包含多个视图的所有ViewGroup（RelativeLayout）都可以整体缩放。

我使用onTouch而不是onDrag，在内部我将尺寸保存在 dp 中并从 dp 转换为像素我乘以（屏幕）密度*缩放因子）

这是我从onTouch ACTION_MOVE调用的方法，xPxInitial，dpLeftInitial，yPxInitial，dpTopInitial的值先前已在ACTION_DOWN中设置。

 @Override
    public boolean moveControl(float xPx, float yPx) {

        int newDpLeft, newDpTop;

        newDpLeft = pixelsToDp((int) (xPx - xPxInitial)) + dpLeftInitial;
        newDpTop = pixelsToDp((int) (yPx - yPxInitial)) + dpTopInitial;

        // Limit for left & top
        if (newDpLeft < 0) newDpLeft = 0;
        if (newDpTop < 0) newDpTop = 0;        


        int oldDpLeft = dpLeft;
        int oldDpTop = dpTop;

        dpLeft = newDpLeft;
        dpTop = newDpTop;
        setDimsFromDps(); 

        // return true is the view is really moved
        return (dpLeft != oldDpLeft || dpTop != oldDpTop);
    }

pixelsToDp

/// Pixels to DP's ....
    public int pixelsToDp(int pixs) {
        return (int) (pixs / (scrDensity * zoomFactor));
    }

setDimsFromDps

protected void setDimsFromDps() {
        RelativeLayout.LayoutParams layPar = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT,
                RelativeLayout.LayoutParams.WRAP_CONTENT);

        // avoid left & top < 0

        layPar.setMargins(Math.max(dpToPixels(dpLeft), 0), Math.max(dpToPixels(dpTop), 0), 0, 0);
        layPar.width = dpToPixels(dpWidth);
        layPar.height = dpToPixels(dpHeight);


        setLayoutParams(layPar);

    }

Hope it will help

捏合和缩放时，在imageview上保持拖放视图位置

1 个答案: