android - 在android中缩放 Canvas 时canvas.getClipBounds().left始终为0

Question

缩放Canvas后的值

canvas.getClipBounds().left 始终为 0

canvas.getClipBounds().top 始终为 0

这些值在缩放时不会改变。是否有任何错误的实现？

Rect clipBounds = new Rect();
int canvasLeft;

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

    clipBounds = canvas.getClipBounds();
    canvas.save();

    canvasLeft = canvas.getClipBounds().left;

    if(scaleGestureDetector.isInProgress()){
        scaleGestureFocusX = this.scaleGestureDetector.getFocusX();
        scaleGestureFocusY = this.scaleGestureDetector.getFocusY();
        canvas.scale(this.scaleFactor, this.scaleFactor, scaleGestureFocusX, scaleGestureFocusY);
    }
    else{

        canvas.scale(this.scaleFactor, this.scaleFactor, scaleGestureFocusX, scaleGestureFocusY);
    }

    canvas.drawBitmap(bitmap, 0, 0, null);
    canvas.drawPath(path, paint);       
    canvas.restore();

}

Answer 1

您在canvas.save()之后调用canvas.getClipBounds().left。这就是为什么每次它返回 0 的原因是新生成的 Canvas 剪辑绑定(bind)始终为 0。

解决方案:先调用canvas.getClipBounds().left，然后调用canvas.save()。