使用AFNetworking上传文件，服务器检测到空流

Question

我正在使用此代码将文件上传到服务器，在服务器上未检测到流，问题是我使用相同的代码，但在不同的项目中它完美运行！我已经包含了相应的标题！到底是怎么回事 ？我花了最后几个小时来解决这个问题请帮忙

-(void)upload
{

NSString *st = [[NSBundle mainBundle] pathForResource:@"R" ofType:@"caf"];
NSData *d = [NSData dataWithContentsOfFile:st];

AFHTTPClient *client= [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:@"http://192.168.0.116:8084/RasaylServer/"]];

NSString *action = @"SendStreamMessage";

NSMutableDictionary *parameters = [NSMutableDictionary dictionary];
[parameters setObject:@"209" forKey:@"param1"];
[parameters setObject:@"205" forKey:@"param2"];
[parameters setObject:@"01/12/2012 15:13" forKey:@"param3"];


NSMutableURLRequest *myRequest = [client multipartFormRequestWithMethod:@"POST" path:action parameters:parameters constructingBodyWithBlock: ^(id <AFMultipartFormData>formData)
                                  {

                                      [formData appendPartWithFileData:d name:@"a" fileName:@"Test2" mimeType:@"audio/x-caf"];

                                  }];

AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:myRequest]; 
[operation setCompletionBlock:^(){


} ];

NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[queue addOperation:operation]; 
[operation start];

operation.completionBlock = ^{   


    if ( operation.error == nil )
        NSLog(@"%@", operation.responseString); 
    else {
        NSLog(@"%@", operation.error);
    }

};



}