剪裁图片导致图片向左旋转

Question

做了一个剪裁图片的程序，调用剪裁：

UIImage* croppedImage = [self imageCrop:imageView toRect:CGRectMake(10.0, 50.0, 320, 100)];

方法：

{
    //create a context to do our clipping in
    CGRect newRect = CGRectApplyAffineTransform(rect, imageViewToCrop.transform);
    UIImage *imageToCrop = imageViewToCrop.image;
    UIGraphicsBeginImageContext(newRect.size);
    CGContextRef currentContext = UIGraphicsGetCurrentContext();
    //create a rect with the size we want to crop the image to
    //the X and Y here are zero so we start at the beginning of our
    //newly created context
    CGRect clippedRect = CGRectMake(0, 0, rect.size.width, rect.size.height);
    CGContextClipToRect( currentContext, clippedRect);
    //draw the image to our clipped context using our offset rect
    CGContextDrawImage(currentContext, newRect, imageToCrop.CGImage);
    //pull the image from our cropped context
    UIImage *cropped = UIGraphicsGetImageFromCurrentImageContext();
    //pop the context to get back to the default
    UIGraphicsEndImageContext();
    return cropped;
}

设置图片到UIImageview的时候，图片向左旋转了。而且我也没办法让他向上旋转，怎么办？

Answer 1

如楼上所说的可能是imageOrientation属性的问题。并且你也没有正确保存scale。这样创建剪裁的图片：

CGImageRef croppedRef = CGBitmapContextCreateImage(currentContext);
UIImage* cropped = [UIImage imageWithCGImage:croppedRef scale:imageToCrop.scale orientation:imageToCrop.imageOrientation];
CGImageRelease(croppedRef);