将图像上传到网络服务会导致图像损坏

我正在尝试从 iPhone 将图像上传到网络服务，但即使文件已成功上传，也无法查看 jpg，它似乎已损坏。

使用以下 c# 代码可以成功上传文件并正常工作：

var url = http://myurl.co.uk/services/service.svc/UploadImage?id=108&ext=png;

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(url);
req.Method = "POST";
req.ContentType = "image/jpeg";

using (var reqStream = req.GetRequestStream())
{
    var bytes = File.ReadAllBytes("C:\\Users\\Chris\\Pictures\\default.png”);
    reqStream.Write(bytes, 0, bytes.Length);
}
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();

Console.WriteLine("HTTP/{0} {1} {2}", resp.ProtocolVersion, (int)resp.StatusCode, resp.StatusDescription);

然而，这是我在 iOS 上尝试的代码，该代码使文件无法查看：

获取图像

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    UIImage *image = [info objectForKey:UIImagePickerControllerOriginalImage];
    // Resize the image from the camera
    UIImage *scaledImage = [image resizedImageWithContentMode:UIViewContentModeScaleAspectFill bounds:CGSizeMake(_photo.frame.size.width/2, _photo.frame.size.height/2) interpolationQuality:kCGInterpolationHigh];
    // Crop the image to a square (yikes, fancy!)
    UIImage *croppedImage = [scaledImage croppedImage:CGRectMake((scaledImage.size.width -_photo.frame.size.width)/2, (scaledImage.size.height -_photo.frame.size.height)/2, _photo.frame.size.width, _photo.frame.size.height)];
    // Show the photo on the screen
    _photo.image = croppedImage;

    NSData *imgData=UIImageJPEGRepresentation(croppedImage,1);
    NSLog(@"Original size:%d",[imgData length]);
    NSData *smallerImage=UIImageJPEGRepresentation(croppedImage, 0.5);
    NSLog(@"End size:%d",[smallerImage length]);
    imageData = imgData;

    NSString *imageName = @"tempImage.jpg";
    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,  NSUserDomainMask, YES);
    NSString * documentsDirectoryPath = [paths objectAtIndex:0];

    NSString *dataPath = [documentsDirectoryPath  stringByAppendingPathComponent:imageName];
    NSData* settingsData = UIImageJPEGRepresentation(croppedImage, 0.5);

    [settingsData writeToFile:dataPath atomically:YES];

    [picker dismissModalViewControllerAnimated:YES];
}

上传图片：

-(void)uploadImageForOfferID:(NSString *)offerID imageExtention:(NSString *)extension withCompletionBlock:(void(^)(NSError *error))block
{
    NSString *imageName = @"tempImage.jpg";
    NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,  NSUserDomainMask, YES);
    NSString * documentsDirectoryPath = [paths objectAtIndex:0];

    NSString *dataPath = [documentsDirectoryPath  stringByAppendingPathComponent:imageName];
    NSData* imageData = [NSData dataWithContentsOfFile:dataPath];

    AFHTTPClient *client = [AFHTTPClient clientWithBaseURL:[NSURL URLWithString:masterURL]];

    NSString *url = [NSString stringWithFormat:@"UploadImage?id=%@&ext=%@", offerID, extension];
    NSMutableURLRequest *request = [client multipartFormRequestWithMethod:@"POST" path:url parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        [formData appendPartWithFileData:imageData name:@"photo" fileName:@"photo.jpg" mimeType:@"image/jpeg"];
    }];

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

    [operation setUploadProgressBlock:^(NSUInteger bytesWritten, long long totalBytesWritten, long long totalBytesExpectedToWrite) {
        NSLog(@"Sent %lld of %lld bytes", totalBytesWritten, totalBytesExpectedToWrite);
    }];

    [operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSLog(@"Complete");
        block(nil);
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Failed");
        NSLog(@"FAILED WITH STATUS CODE %d - error description: %@", operation.response.statusCode, error.description);
        block(error);
    }];
    [operation start];
}

此方法首先将图像保存到文件，然后上传。我也尝试只上传数据NSData *smallerImage=UIImageJPEGRepresentation(croppedImage, 0.5);但结果相同。

我在上传时错过了一些东西吗？

Thanks

编辑 - -

比较模拟器中的文件和上传的文件。模拟器文件是2,538 bytes (4 KB on disk)并且上传的文件稍大一些2,698 bytes (4 KB on disk)原始模拟器图像显示缩略图，但上传的图像没有！ 上传的图像可以使用 Photoshop 打开，但不能使用 Safari 或 Chrome 打开。

是否与您发送带有类型的图像有关image/jpeg当您在提供的代码中指向的文件实际上是.png文件并且应该使用image/png?