自己写的一个网络请求图片居中工具类

+(void)cropToolWithUrl:(NSString *)url imageView:(UIImageView *)imageView{
    [imageView sd_setImageWithURL:[NSURL URLWithString:url] completed:^(UIImage * _Nullable image, NSError * _Nullable error, SDImageCacheType cacheType, NSURL * _Nullable imageURL) {
        CGFloat width = image.size.width;
        CGFloat height = image.size.height;
        if (width==height) {
            
        }else{
            CGSize  contextSize;
            CGFloat context_x_ctm;
            if(width>height){
                contextSize=CGSizeMake(height, height);
                context_x_ctm=-(width-height)/2;
                
            }else{
                contextSize=CGSizeMake(width, width);
                context_x_ctm=-(height-width)/2;
            }
            
            UIImage *croppedImage = nil;
            UIGraphicsBeginImageContextWithOptions(contextSize, true,1.0);
            {
                CGContextRef context = UIGraphicsGetCurrentContext();
                
                CGContextTranslateCTM(context, context_x_ctm, 0);
                [image drawAtPoint:CGPointZero];
                
                croppedImage = UIGraphicsGetImageFromCurrentImageContext();
            }
            UIGraphicsEndImageContext();
            
            UIImage *newImg =  [UIImage imageWithCGImage:croppedImage.CGImage scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
            imageView.image=newImg;
        }
    }];
}