setDownloadProgressBlock中的totalBytesExpectedToRead保持为-1，直到下载完成 [英] totalBytesExpectedToRead in setDownloadProgressBlock remains -1 until download is done

问题描述

我一直在谷歌搜索无效，希望对此有帮助。

我尝试使用AFHTTPRequestOperation流（通过设置输出流）下载图像。
它下载文件，没问题。
但是进度条不会显示正确，因为totalBytesExpectedToRead总是返回-1，下载完成后只返回正确的值。

流？
或者我做错了？

我的代码如下。

提前感谢！ （NSString *）locationToSave参数：（NSDictionary *）paramDict callId：（NSString *）callId {// / p>

（void）invokeAsynchronousSTREAMING

  NSMutableURLRequest * request = [[AFServerAPIClient sharedClient] requestWithMethod：@GET
 path：path 
参数：paramDict] ; 
 
 AFHTTPRequestOperation * operation = [[AFHTTPRequestOperation alloc] initWithRequest：request]; 
 
 if（locationToSave！= nil）{
 operation.outputStream = [NSOutputStream outputStreamToFileAtPath：locationToSave append：NO]; 
} 
 
 [operation setCompletionBlockWithSuccess：^（AFHTTPRequestOperation * operation，id responseObject）{
 
 // DO SOMETHING 
 
} 
 failure：^（AFHTTPRequestOperation * operation，NSError * error）{
 // DO SOMETHING 
} 
]; 
 
 [操作setDownloadProgressBlock：^（NSInteger bytesRead，long long totalBytesRead，long long totalBytesExpectedToRead）{
 
 NSLog（@invokeAsyncronousSTREAMING  -  Received％lld of％lld bytes，totalBytesRead ，totalBytesExpectedToRead）; 
 
 // DO SOMETHING 
}]; 
 
 [operation start]; 
  

} // end invokeAsyncStreaming

解决方案

如果服务器未设置 Content-Length -1 >响应中的HTTP头。

在这种情况下，建议您改用不确定的进度指示器。

I have been googling to no avail, and hope for your help on this.

I tried to download an image using AFHTTPRequestOperation streaming (by setting outputstream). It downloads the file, no problem. But the progress bar wont display correct, because totalBytesExpectedToRead always returns -1, and only returns the correct value when download is complete.

Is this the nature of streaming? Or did I do something wrong?

My code below.

Thanks in advance!

(void)invokeAsynchronousSTREAMING:(NSString*)path locationToSave:(NSString*)locationToSave parameters:(NSDictionary*)paramDict callId:(NSString*)callId {

NSMutableURLRequest *request = [[AFServerAPIClient sharedClient] requestWithMethod:@"GET" 
                                                                              path:path 
                                                                        parameters:paramDict];

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];

if(locationToSave!=nil) {
    operation.outputStream = [NSOutputStream outputStreamToFileAtPath:locationToSave append:NO];
}

[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject)  {

   //DO SOMETHING

} 
    failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        //DO SOMETHING
    }
 ];

[operation setDownloadProgressBlock:^(NSInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {

    NSLog(@"invokeAsyncronousSTREAMING - Received %lld of %lld bytes", totalBytesRead, totalBytesExpectedToRead);

    //DO SOMETHING
}];

[operation start];

}//end invokeAsyncStreaming

解决方案

Download progress may return -1 if the server does not set the Content-Length HTTP header in the response.

In this case, it is recommended that you use an indeterminate progress indicator instead.

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