为什么 NSURLSession uploadTaskWithRequest:fromData: 无法上传到 php 服务器？

php 代码工作正常。我已经从同一服务器上的 html 表单上传了文件。上传的文件大小从 40K 到 2.0M 不等，因此其大小不高。在运行 PHP 5.3 的服务器上激活文件上传

我发现了很多这样的帖子（还没有答案）：https://stackoverflow.com/questions/19710388/using-nsurlsession-to-upload-an-image https://stackoverflow.com/questions/19710388/using-nsurlsession-to-upload-an-image.

这个使用 uploadTask With Request:from File: 而不是表单数据：NSURLSession 确保上传有效 https://stackoverflow.com/questions/23549635/nsurlsession-make-sure-upload-worked

这是 NSURLSessionDataTask 而不是 uploadTaskWithRequest：NSURLSession 没有接收数据 https://stackoverflow.com/questions/22914877/no-data-receiving-with-nsurlsession

有些帖子似乎说 uploadTaskWithRequest:fromData: 根本不起作用：NSURLSession：通过后台传输上传资产 https://stackoverflow.com/questions/19985353/nsurlsession-uploading-assets-with-background-transfer 使用 NSURLSession 异步上传不起作用，但同步 NSURLConnection 可以 https://stackoverflow.com/questions/20893171/asynchronous-upload-with-nsurlsession-will-not-work-but-synchronous-nsurlconnect/20896632?noredirect=1#comment39074802_20896632 and 将图像从 iOS 上传到 PHP https://stackoverflow.com/questions/23667226/upload-image-from-ios-to-php/23682958#comment39072810_23682958

我已经制作了应用程序，使其返回 HTTP 代码，并且我得到代码 200。上传后，服务器 error_log 文件中没有任何内容。一切似乎都工作正常，但无论发生什么，文件都不会写入服务器。我还有什么想法可以尝试找出问题所在吗？

这是 php 代码：

<?php
$file='';
$uploaddir='';

////////////////
echo 'file count=', count($_FILES),"\n";
var_dump($_FILES);
echo "\n";
////////////////

if(isset($_FILES['userfile']['name'])){
      $uploaddir = './photos/'; //Uploading to same directory as PHP file
      $file = basename($_FILES['userfile']['name']);
      echo "file is set";
      $uploadFile = $file;
      $randomNumber = rand(0, 99999); 
      $newName = $uploaddir . $uploadFile;
        if (is_uploaded_file($_FILES['userfile']['tmp_name'])) {
            echo "Temp file uploaded. \r\n";
        } else {
            echo "Temp file not uploaded. \r\n";
        }
   if (move_uploaded_file($_FILES['userfile']['tmp_name'], $newName)) {
         $postsize = ini_get('post_max_size'); //Not necessary, I was using these
         $canupload = ini_get('file_uploads'); //server variables to see what was 
         $tempdir = ini_get('upload_tmp_dir'); //going wrong.
         $maxsize = ini_get('upload_max_filesize');
         echo "\r\n" .  $_FILES['userfile']['size'] . "\r\n" . $_FILES['userfile']['type'] ;
    }
}
?>

这是 iOS 代码：

- (void)uploadImage:(UIImage*)image {

    // 0 Define URL
    NSData *imageData = UIImageJPEGRepresentation(image, 0.6);
    NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://www.myserver.com/app/photos/uploadPhoto.php"]];
    NSString *boundary = @"0xKhTmLbOuNdArY";
    NSString *filename = [NSString stringWithFormat:@"someName.jpg"];
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url];
    [request setHTTPMethod:@"POST"];
    NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
    NSURLSession *upLoadSession = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];

    // 4 Create object to put content into...
    NSMutableData *body = [NSMutableData data];
    [request addValue:contentType forHTTPHeaderField:@"Content-Type"];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithString:[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"userfile\" filename=\"%@\"\r\n",filename]] dataUsingEncoding:NSUTF8StringEncoding]];
    //[body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"Content-Type: image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];

    [body appendData:[NSData dataWithData:imageData]];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];


    //Not used with this:https://stackoverflow.com/questions/20893171/asynchronous-upload-with-nsurlsession-will-not-work-but-synchronous-nsurlconnect/20896632?noredirect=1#comment39074802_20896632
    //[request setHTTPBody:body];


    __block NSString *stringForText = @"Hola";
    ///////////////////////////////////////////////////
    // 3
    self.uploadTask = [upLoadSession uploadTaskWithRequest:request fromData:body completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
        // ...
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*) response;
        int errorCode = httpResponse.statusCode;
        NSString *errorStatus = [NSString stringWithFormat:@"%d",errorCode];

        NSString *responseString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        NSString *totalResponse = [errorStatus stringByAppendingString:responseString];

        stringForText = totalResponse;
        [self updateView:stringForText];
        //UIAlertView *alertme = [[UIAlertView alloc] initWithTitle:@"error" message:totalResponse delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:nil];
        //[alertme show];
        // 4
        self.uploadView.hidden = NO;
        [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    }];


    // 5
    [_uploadTask resume];
}

-(void)updateView:(NSString*)texto{
    dispatch_sync(dispatch_get_main_queue(), ^{
        self.myTextView.text = texto;
    });

}

我对该文件夹有 777 权限。正如我所说，我已经能够通过 html 表单从同一 php 脚本上传并写入该文件夹。

对于 http 错误代码，totalResponse 为 200，对于 php 转储，count=0 以及 array(0) {}。

Here is the image of the response from the server right in the app:

我在回显上传的临时文件后添加了这些行：

$body = $HTTP_RAW_POST_DATA;
echo "\n REQUEST" . $body;

但我只得到这个：

file count=1 array(1) { ["user file"]=> array(5) { ["name"]=> string(12) "DrinkCO2.png" ["type"]=> string(9) "image/png" ["tmp_name"]=> string(14) "/tmp/phpxg7oLZ" ["error"]=> int(0) ["size"]=> int(190550) } } file is setTemp file uploaded. REQUEST 190550 image/png

它没有缺少冒号，而是缺少分号。

"name=\"userfile\" : filename=\"%@\"\r\n""

应该

"name=\"userfile\"; filename=\"%@\"\r\n""

至少这是你的代码对我有用的唯一方法（顺便谢谢！）。