为uiscrollView生成CGRECT的公式,该公式按比例显示uiimage

编辑: 以前的版本是根据视图而不是相反的方式调整图像大小。我认为这应该纠正:

double imgRatio = imageSize.width / imageSize.height;
double viewRatio = viewSize.width / viewSize.height;

if ( imgRatio >= viewRatio )
{
    initialPos.size.width = imageSize.width;
    initialPos.size.height = imageSize.width / viewRatio;
    initialPos.origin.x = 0;
    initialPos.origin.y = (imageSize.height - initialPos.size.height) / 2;
}
else
{
    initialPos.size.height = imageSize.height;
    initialPos.size.width = imageSize.height * viewRatio;
    initialPos.origin.y = 0;
    initialPos.origin.x = (imageSize.width - initialPos.size.width) / 2;
}