相关疑难解决方法(0)

-(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse    *)response {
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
    if([recievedData length]) [ recievedData setLength:0 ];

    download_size =[response expectedContentLength];
}

我有这个代码.download_size是NSInteger.expectedContentLenght总是返回:-1.也许有人知道为什么？我尝试使用很长时间,但效果是一样的.

感谢帮助.

我遇到了一个奇怪的问题.我使用NSURLSession和从Internet加载文件NSURLSessionDownloadTask.这是代码

NSURLSessionConfiguration *sessionConfiguration =
[NSURLSessionConfiguration backgroundSessionConfiguration:kSessionId];
self.session = [NSURLSession sessionWithConfiguration:sessionConfiguration
                                             delegate:self
                                        delegateQueue:[NSOperationQueue new]];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
NSURLSessionDownloadTask *downloadTask = [self.session downloadTaskWithRequest:request];
[downloadTask resume];

我的班级被宣布为NSURLSessionDownloadDelegate,我得到了很好的回调.但是当系统调用委托方法时

- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite
{
    NSLog(@"totalBytesExpectedToWrite: %lld", totalBytesExpectedToWrite);
    NSLog(@"%lld", totalBytesWritten);
}

totalBytesExpectedToWrite总是相等-1,我没有能力向用户显示进度,因为我不知道下载文件的大小.

你能告诉我哪里弄错了吗？

我在服务器端获得的请求缺少content-length每个多部分的请求.

我试图更改标题但仍然无法显示.

我使用Alamofire/multipart form-data成功地将图像文件和一些数据从设备/模拟器发送到服务器.

 var parameters = […]

    let url = try! URLRequest(url: “URL”, method: .post, headers: ["Content-type": "multipart/form-data"])

    Alamofire.upload(multipartFormData: { (multipartFormData) in
        for (key, value) in parameters {
            multipartFormData.append((value.data(using: String.Encoding.utf8)!), withName:key)

        }
        multipartFormData.append(UIImageJPEGRepresentation(image!, 0.5)!, withName: “Image”, mimeType: "image/jpeg")

    }, to: "\(url)" , encodingCompletion: {(encodingResult) in

        switch encodingResult {
        case .success(let upload, _, _):
            //print(result)
            upload.uploadProgress(closure: { (Progress) in

                self.progressView.progress = Float(Progress.fractionCompleted)
                print("Upload Progress: \(Progress.fractionCompleted)")
            })


            print("REQUEST = \(request)")
            print(encodingResult)

            upload.responseJSON { response in

                //self.delegate?.showSuccessAlert()
                print( …

我正在尝试在下载文件时查看进度条.该文件是通过PHP生成的,我发送的是"Content-length"标题,实际上可以正常工作.

文件下载正常,这不是问题.不幸的是,我无法获取文件大小以便正确显示进度条.

这是我的代码:

write_to_filename = [issue objectForKeyedSubscript:filename];
NSString *post =[[NSString alloc] initWithFormat:@"user_id=%@&email=%@&password=%@",[userData stringForKey:@"userId"],[userData stringForKey:@"email"],[userData stringForKey:@"password"]];
NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];

NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://MY_API_REQUEST"]];

NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

[request setValue:@"application/pdf" forHTTPHeaderField:@"Accept"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPMethod:@"POST"];
[request setHTTPBody:postData];
[NSURLConnection connectionWithRequest:request delegate:self];

[issueArray writeToFile:[self saveFilePath] atomically:YES];

NSURLConnection

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse 

*)response {

    NSLog(@"%lld",[response expectedContentLength]);
    _responseData = [[NSMutableData alloc] init];

}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [_responseData appendData:data];
}

- (NSCachedURLResponse …