IOS为图片截图

-(UIImage*)getSubImage:(UIImage*)inputImage{
float scale = inputImage.size.height/inputImageView.frame.size.height;
CGRect mySubImgBounds = CGRectMake((CGRectGetMinX(clipingAreaView.frame)-CGRectGetMinX(inputImageView.frame))*scale, (CGRectGetMinY(clipingAreaView.frame)-CGRectGetMinY(inputImageView.frame))*scale, clipingAreaView.frame.size.width*scale, clipingAreaView.frame.size.height*scale);
CGImageRef subImageRef = CGImageCreateWithImageInRect(inputImageView.image.CGImage, mySubImgBounds);
UIImage *tempImg = [UIImage imageWithCGImage:subImageRef];
return tempImg;
}