iphone UIImage 如何生成缩略图

来源：互联网发布：守望先锋数据怎么看编辑：程序博客网时间：2024/05/17 22:36

+ (UIImage *)generatePhotoThumbnail:(UIImage *)image {// Create a thumbnail version of the image for the event object.CGSize size = image.size;CGSize croppedSize;CGFloat ratio = 64.0;CGFloat offsetX = 0.0;CGFloat offsetY = 0.0;// check the size of the image, we want to make it // a square with sides the size of the smallest dimensionif (size.width > size.height) {offsetX = (size.height - size.width) / 2;croppedSize = CGSizeMake(size.height, size.height);} else {offsetY = (size.width - size.height) / 2;croppedSize = CGSizeMake(size.width, size.width);}// Crop the image before resizeCGRect clippedRect = CGRectMake(offsetX * -1, offsetY * -1, croppedSize.width, croppedSize.height);CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], clippedRect);// Done cropping// Resize the imageCGRect rect = CGRectMake(0.0, 0.0, ratio, ratio);UIGraphicsBeginImageContext(rect.size);[[UIImage imageWithCGImage:imageRef] drawInRect:rect];UIImage *thumbnail = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();// Done Resizingreturn thumbnail;}

原文地址：http://zl4393753.iteye.com/blog/1503822

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