如何使用 AFNetworking AFHTTPRequestOperationManager 显示 ProgressBar答案

【问题标题】：How to show ProgressBar With AFNetworking AFHTTPRequestOperationManager如何使用 AFNetworking AFHTTPRequestOperationManager 显示 ProgressBar
【发布时间】：2015-06-28 08:28:45
【问题描述】：

我试图在从 url 下载 JSON 时显示进度条。 JSON 正在正确下载，但我不确定如何显示进度条。我试过使用UIProgressView，但它没有显示在屏幕上。任何建议将不胜感激。

CGFloat width = [UIScreen mainScreen].bounds.size.width;
CGFloat height = [UIScreen mainScreen].bounds.size.height;

CGRect rect = CGRectMake(width/2, height/2, width/5, height/5);
UIProgressView *myProgressView = [[UIProgressView alloc]initWithFrame:rect];
myProgressView.progressViewStyle = UIProgressViewStyleBar;
[self.view addSubview:myProgressView];

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];    
[manager GET:@"https:urlWithJson" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
      [operation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead)
       {
           myProgressView.progress = (float)totalBytesRead / totalBytesExpectedToRead;
       }];
      [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
          NSLog(@"operation Completed");
      } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
          NSLog(@"ERROR");
      }];

      [operation start];
  } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
      NSLog(@"timeout Error: %@", error);
  }];

【问题讨论】：

totalBytesExpectedToRead 有值吗？ HTTP 标头必须包含文档的大小才能获得预期的总字节数。
我尝试在 setDownloadProgressBlock 中放入一个 NSLog 语句，但它没有打印任何内容。有没有更好的方法可以实现我想要的？

标签： ios objective-c afnetworking-2 uiprogressview

【解决方案1】：

您在成功块内设置了下载进度块，这有点太晚了；）

试试这个：

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];    
AFHTTPRequestOperation *operation = [manager GET:@"https:urlWithJson" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSLog(@"Complete");
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error: %@", error);
}];

[operation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
    myProgressView.progress = (float)totalBytesRead / totalBytesExpectedToRead;
}];

【讨论】：

【解决方案2】：

Swift 的简单解决方案：

let progress: UIProgressView? //for example, reference to IBOutlet
let manager = AFHTTPRequestOperationManager()
let operation = manager.POST(query, parameters: parameters, constructingBodyWithBlock: { multipartData in

             //do sth with your multipartData
    }, success: { operation, response in

            //success
    }) { operation, error in

            //failure
}

progress?.setProgressWithUploadProgressOfOperation(operation!, animated: true)

你什么也不做。这足以显示您的视图的进度。

【讨论】：