1.增加壓縮圖片方法

+ (UIImage *)compressImage:(UIImage *)image
{
    float imageWidth = image.size.width;
    float imageHeight = image.size.height;
    float width = 640;
    float height = image.size.height/(image.size.width/width);
    
    float widthScale = imageWidth /width;
    float heightScale = imageHeight /height;

    UIGraphicsBeginImageContext(CGSizeMake(width, height));
    
    if (widthScale > heightScale) {
        [image drawInRect:CGRectMake(0, 0, imageWidth /heightScale , height)];
    }
    else {
        [image drawInRect:CGRectMake(0, 0, width , imageHeight /widthScale)];
    }
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    return newImage;
    
}

2.修改 sd_imageWithData 方法

+ (UIImage *)sd_imageWithData:(NSData *)data {
    if (!data) {
        return nil;
    }
    
    UIImage *image;
    NSString *imageContentType = [NSData sd_contentTypeForImageData:data];
    if ([imageContentType isEqualToString:@"image/gif"]) {
        image = [UIImage sd_animatedGIFWithData:data];
    }
#ifdef SD_WEBP
    else if ([imageContentType isEqualToString:@"image/webp"])
    {
        image = [UIImage sd_imageWithWebPData:data];
    }
#endif
    else {
        image = [[UIImage alloc] initWithData:data];
        if (data.length/1024 > 128) {
            image = [self compressImageWith:image];
            data =UIImageJPEGRepresentation(image,1.0);
        }
        UIImageOrientation orientation = [self sd_imageOrientationFromImageData:data];
        if (orientation != UIImageOrientationUp) {
            image = [UIImage imageWithCGImage:image.CGImage
                                        scale:image.scale
                                  orientation:UIImageOrientationUp];
        }
    }


    return image;
}