ios - UIImage 居中放大

Question

我有缩放 UIImage 的方法

- (UIImage*)croppedImageWithImage:(UIImage *)image zoom:(CGFloat)zoom
{
    CGFloat zoomReciprocal = 1.0f / zoom;

    CGPoint offset = CGPointMake(40, 40);
    CGRect croppedRect = CGRectMake(offset.x, offset.y, image.size.width * zoomReciprocal, image.size.height * zoomReciprocal);

    CGImageRef croppedImageRef = CGImageCreateWithImageInRect([image CGImage], croppedRect);

    UIImage* croppedImage = [[UIImage alloc] initWithCGImage:croppedImageRef scale:[image scale] orientation:[image imageOrientation]];

    CGImageRelease(croppedImageRef);

    return croppedImage;
}

缩放后如何保存图像宽度和高度？

Answer 1

要保存缩放图像：

UIImageWriteToSavedPhotosAlbum(croppedImage, nil, nil, nil);

保存图像尺寸

CGSize imageSize = CGSizeMake(croppedImage.size.width, croppedImage.size.height);

Answer 2

如果要保存图像的宽度和高度，只需创建 CGSize 变量并保存如下

CGSize croppedSize = croppedImage.size