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我正在尝试使用允许缩放和平移但会阻止用户将图像平移到屏幕外的画布显示图像。我已经能够停止平移，但是当图片缩放时，它会在图像边缘之前停止。即使放大，我也需要能够平移到图像的边缘。任何帮助将不胜感激。

我的代码显示图像，停止平移和缩放：

    @Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.save();

        if (mPosX < displayWidth - mIcon.getIntrinsicWidth()){
            mPosX = displayWidth - mIcon.getIntrinsicWidth();}
        if (mPosX > 0){
            mPosX = 0; }
        if (mPosY < displayHeight - mIcon.getIntrinsicHeight()){
            mPosY = displayHeight - mIcon.getIntrinsicHeight();}
        if (mPosY > 0){
            mPosY = 0; }

        canvas.translate(mPosX, mPosY);
        canvas.scale(mScaleFactor, mScaleFactor);
        mIcon.draw(canvas);
        canvas.restore();
    }

    private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            mScaleFactor *= detector.getScaleFactor();

            // Don't let the object get too small or too large.
            mScaleFactor = Math.max(0.42f, Math.min(mScaleFactor, 5.0f));

            invalidate();
            return true;
        }
    }
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1 回答 1

0

与此非常相似：Zooming in android - keep image in view

于 2011-10-04T21:31:28.327 回答