ios - 使用iOS中的AFNetworking，确定故障响应是服务器错误还是连接错误的最佳方法是什么？

Question

使用iOS中的AFNetworking，确定故障响应是服务器错误还是连接错误的最佳方法是什么？

例如，如果由于连接错误导致上传失败，我可能要在一段时间后自动重试上传。相反，如果由于服务器错误导致上传失败，我将希望永久停止尝试该请求。 (我不想重试的错误最多是400和500个错误。)

请告诉我如何最轻松地确定我是否只是看到连接错误或服务器错误？

Answer 1

我使用以下UIImageView类别。尝试在5秒钟延迟后重新加载图像。

h文件:

#import "UIImageView+AFNetworking.h"

@interface UIImageView (ConvenienceAdditions)

- (void)setAutoRetryImageWithURL:(NSURL *)url;
- (void)setAutoRetryImageWithURL:(NSURL *)url completion:(CompletionBlockCommon)block;
- (void)setAutoRetryImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholderImage completion:(CompletionBlockCommon)block;
- (void)setAutoRetryImageWithURLRequest:(NSURLRequest *)urlRequest placeholderImage:(UIImage *)placeholderImage completion:(CompletionBlockCommon)block;

@end

m文件:

#import "UIImageView+ConvenienceAdditions.h"

static NSTimeInterval kDGImageReloadingAttemptInterval = 5;

@implementation UIImageView (ConvenienceAdditions)

- (void)setAutoRetryImageWithURL:(NSURL *)url
{
    [self setAutoRetryImageWithURL:url completion:nil];
}

- (void)setAutoRetryImageWithURL:(NSURL *)url completion:(CompletionBlockCommon)block
{
    [self setAutoRetryImageWithURL:url placeholderImage:nil completion:block];
}

- (void)setAutoRetryImageWithURL:(NSURL *)url placeholderImage:(UIImage *)placeholderImage completion:(CompletionBlockCommon)block
{
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request addValue:@"image/*" forHTTPHeaderField:@"Accept"];
    [self setAutoRetryImageWithURLRequest:request placeholderImage:placeholderImage completion:block];
}

- (void)setAutoRetryImageWithURLRequest:(NSURLRequest *)urlRequest placeholderImage:(UIImage *)placeholderImage completion:(CompletionBlockCommon)block
{
    __weak typeof (self) weakImageView = self;
    [self setImageWithURLRequest:urlRequest placeholderImage:placeholderImage success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {
        __strong __typeof(weakImageView)strongImageView = weakImageView;
        if (block){
            block(image, nil);
        }
        else{
            strongImageView.image = image;
        }
    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
        if (error.code == NSURLErrorCancelled){ // Check error's code
            return ;
        }
        else if (response.statusCode >= 400) // Check response's code
        {
            return;
        }
        else{
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, kDGImageReloadingAttemptInterval * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
                [weakImageView setAutoRetryImageWithURLRequest:urlRequest placeholderImage:placeholderImage completion:block];
            });
        }
    }];
}

@end

应按以下方式使用:

[someImageView setAutoRetryImageWithURL:someImageURL];