UITableView中改变UIImage尺寸的方法

UIImage *image = [UIImage imageNamed:@"YourImage.png"];
            UIImage *tempImage = nil;
            CGSize targetSize = CGSizeMake(48,48); //你想要的图片尺寸
            UIGraphicsBeginImageContext(targetSize);

            CGRect thumbnailRect = CGRectMake(0, 0, 0, 0);
            thumbnailRect.origin = CGPointMake(0.0,0.0);
            thumbnailRect.size.width  = targetSize.width;
            thumbnailRect.size.height = targetSize.height;

            [image drawInRect:thumbnailRect];

            tempImage = UIGraphicsGetImageFromCurrentImageContext();

            UIGraphicsEndImageContext();
            cell.img.image = tempImage; //这里我是自定义了cell，将Image重置为新的tempImage即可