剪切图的生成大小为何要乘上屏幕的倍数？ 我想拿到屏幕剪切的大小图没有配置项可以设置 #1712

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1. banchichen commented on Feb 6, 2025

   

   banchichen

   on Feb 6, 2025

   Owner

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   能详细介绍下，目前这种效果，对你的不利影响是？
2. 0x1306a94 commented on Sep 30, 2025

   

   0x1306a94

   on Sep 30, 2025

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   @banchichen 原图尺寸小，但经过这么裁剪后。尺寸变大了。
3. 0x1306a94 commented on Sep 30, 2025

   

   0x1306a94

   on Sep 30, 2025

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   下面的实现是按照原图尺寸裁剪

   + (UIImage *)cropImageView:(UIImageView *)imageView toRect:(CGRect)rect zoomScale:(double)zoomScale containerView:(UIView *)containerView {
           CGImageRef sourceImageRef = imageView.image.CGImage;
       if (sourceImageRef == NULL) {
           return nil;
       }
       
       /**
        * 视图结构如下
        * containerView
        *     UICollectionView
        *          TZPhotoPreviewCell
        *              contentView
        *                  TZPhotoPreviewView
        *                      UIScrollView
        *                          imageContainerView (scrollview 的 zoomingView)
        *                              imageView
        *      cropView
        *
        *  rect 对应了 cropView.frame
        *
        */
       
       /// imageView 不是UIScrollView 的 zoomingView，所以需要取superview
       CGRect cutRect = [imageView.superview convertRect:rect fromView:containerView];
       CGSize imageSize = imageView.image.size;
       /// 图片与 控件的比例
       CGFloat scale = imageSize.width / CGRectGetWidth(imageView.superview.frame) * zoomScale;
       /// 将剪裁区域坐标转换到图片尺寸上
       cutRect = CGRectMake(cutRect.origin.x * scale, cutRect.origin.y * scale, cutRect.size.width * scale, cutRect.size.height * scale);
       cutRect = CGRectIntersection(cutRect, CGRectMake(0, 0, imageSize.width, imageSize.height));
       if (CGRectIsNull(cutRect) || CGRectIsEmpty(cutRect)) {
           return nil;
       }
       
       CGRect flatCutRect = cutRect;
       flatCutRect.size.width = fmin(ceil(flatCutRect.size.width), imageSize.width);
       flatCutRect.size.height = fmin(ceil(flatCutRect.size.height), imageSize.height);
       if (CGPointEqualToPoint(flatCutRect.origin, CGPointZero) && CGSizeEqualToSize(flatCutRect.size, imageSize)) {
           // 尺寸一致,不执行裁剪处理
           return [[TZImageManager manager] fixOrientation:imageView.image];
       }
       
       CGImageRef cropedImageRef = CGImageCreateWithImageInRect(sourceImageRef, cutRect);
       if (cropedImageRef == NULL) {
           return nil;
       }
       UIImage *cropedImage = [UIImage imageWithCGImage:cropedImageRef];
       cropedImage = [[TZImageManager manager] fixOrientation:cropedImage];
       CGImageRelease(cropedImageRef);
       return cropedImage;
   }