我可以通过（10,10,320,312）等坐标裁剪图像吗？ [英] can i crop image by coordinates like (10,10,320,312)?

问题描述

目标：缩放后如何裁剪图像。在以（10,10,320,312）等预定义坐标缩放后，我可以裁剪图像吗？我的UIImageView有这个大小吗？

Goal : How Crop a image after zooming. can i crop image after zooming at predefined coordinates like (10,10,320,312). my UIImageView has this size?

我在 UIScrollView UIImageView c $ c>，然后可以缩放图像。我想要在缩放后按 cropButton 后在 UIImage 中显示的图像被裁剪。我希望图像的大小等于 UIImageView 大小。

I have a UIImageView in a UIScrollView and I can zoom my image. I wants after zooming when I press cropButton the image which is displaying in UIImage is cropped. I wants size of image equal to UIImageView size.

感谢!!

缩放前

缩放并裁剪后

before zooming
after zoom and crop

我的代码在这里。

-(void)cropButtonClicked
{   
    //Calculate the required area from the scrollview
    CGRect visibleRect;
    float scale = 1.0f/scroll.zoomScale;
    visibleRect.origin.x = scroll.contentOffset.x * scale;
    visibleRect.origin.y = scroll.contentOffset.y * scale;
    visibleRect.size.width = scroll.bounds.size.width * scale;
    visibleRect.size.height = scroll.bounds.size.height * scale;

    UIImage *image = [self imageByCropping:imageView.image toRect:visibleRect];

    imageView.image=image;


}


- (UIImage*)imageByCropping:(UIImage *)myImage toRect:(CGRect)cropToArea{
CGImageRef cropImageRef = CGImageCreateWithImageInRect(myImage.CGImage, cropToArea);
UIImage* cropped = [UIImage imageWithCGImage:cropImageRef];

CGImageRelease(cropImageRef);
return cropped;
}
I use this logic.. Am I RIGHT? (May be i have to check my ScrollView programming)

推荐答案

愿这段代码对您有用。

May this code use full for you..!!

CGSize itemSize = CGSizeMake(newWidth, newHeight);<br>
UIGraphicsBeginImageContextWithOptions(itemSize, NO, 0);<br>
CGRect imageRect = CGRectMake(0, 0, newWidth, newHeight);<br>
[image drawInRect:imageRect];<br>
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();<br>
UIGraphicsEndImageContext();

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