SDWebImage3.6.4内存暴涨问题

• 原因： sd3.6.4 图片为高清或者 图片分辨率高的话sd根据图片分配的内存空间会很大，导致程序内存暴涨
• 解决方案
  • 当控制器内存到一定程度释放聂村重新加载
  • 修改sd

                 将等比压缩过的image在赋在转成data赋给self.imageData
                 NSData *data = UIImageJPEGRepresentation(image, 1);
                 self.imageData = [NSMutableData dataWithData:data];
     +(UIImage *)compressImageWith:(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;

    // 创建一个bitmap的context
    // 并把它设置成为当前正在使用的context
    UIGraphicsBeginImageContext(CGSizeMake(width, height));

    if (widthScale > heightScale) {
        [image drawInRect:CGRectMake(0, 0, imageWidth /heightScale , height)];
    }
    else {
        [image drawInRect:CGRectMake(0, 0, width , imageHeight /widthScale)];
    }

    // 从当前context中创建一个改变大小后的图片
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    // 使当前的context出堆栈
    UIGraphicsEndImageContext();

    return newImage;

}

    else {
        image = [[UIImage alloc] initWithData:data];
        if (data.length/1024 > 128) {
            image = [self compressImageWith:image];
        }
        UIImageOrientation orientation = [self sd_imageOrientationFromImageData:data];
        if (orientation != UIImageOrientationUp) {
            image = [UIImage imageWithCGImage:image.CGImage