Points与Pixels ios

Question

我有uiview，可以放大和缩小

我使用下面的命令将它与pinchRecognizerMeasure关联起来

pinchRecognizerMeasure = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(MeasureAndDraw:)];
[pinchRecognizerMeasure setDelegate:self];
[DrawLine addGestureRecognizer:pinchRecognizerMeasure];
[pinchRecognizerMeasure release];

MeasureAndDraw的代码

    // get position of touches, for example:
    NSUInteger num_touches = [pinchRecognizerMeasure numberOfTouches];

    // save locations to some instance variables, like `CGPoint location1, location2;`
    if (num_touches >= 1) {

        DrawLine.startPoint = [pinchRecognizerMeasure locationOfTouch:0 inView:DrawLine];
    }
    if (num_touches >= 2) {

        DrawLine.endPoint = [pinchRecognizerMeasure locationOfTouch:1 inView:DrawLine];
    }

startPoint，endPoint都是CGPoint，我想得到与它相同的像素

我该怎么做呢?这样做对吗？

startPoint.X * DrawLine.contentScaleFactor来获取pixl x坐标，或者我应该怎么做

我读了http://developer.apple.com/library/ios/#documentation/2DDrawing/Conceptual/DrawingPrintingiOS/GraphicsDrawingOverview/GraphicsDrawingOverview.html，但是很困惑

任何建议

Answer 1

如果确实需要，可以查看UIView的contentScaleFactor属性来在设备上的点和像素之间进行转换。