UWP 使用Windows.Web.Http命名空间下的HttpClient使用post方法，上传图片服务器

1.从相册里面选取图片

         /// <summary>
         /// 1.1 从相册里面选取图片
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private async void btnPhoto_Click(object sender, RoutedEventArgs e)
         {
             //创建和自定义 FileOpenPicker (从本地获取一张图片)
             FileOpenPicker picker = new FileOpenPicker();
             picker.ViewMode = PickerViewMode.Thumbnail; //可通过使用图片缩略图创建丰富的视觉显示，以显示文件选取器中的文件
             picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;//对话框打开时的默认路径(图片库)
             //设置可选择的文件类型
             picker.FileTypeFilter.Add(".jpg");
             picker.FileTypeFilter.Add(".jpeg");
             picker.FileTypeFilter.Add(".png");
             picker.FileTypeFilter.Add(".gif");
             //选取单个文件
             StorageFile file = await picker.PickSingleFileAsync();
             if (file != null)
             {
                 CutPicture(file);//裁剪图片
             }
         }

2.从相机里面选取图片

         /// <summary>
         /// 1.2 相机
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private async void btnCamera_Click(object sender, RoutedEventArgs e)
         {
             CameraCaptureUI captureUI = new CameraCaptureUI();
             captureUI.PhotoSettings.Format = CameraCaptureUIPhotoFormat.Jpeg;//注意:这里只设置了返回图片格式:Jpeg如果是:Png(手机可以显示,在核心后台图片不显示)和JpegXR(都不显示)会报错;;根据实际情况来
             captureUI.PhotoSettings.AllowCropping = false;
             StorageFile photo = await captureUI.CaptureFileAsync(CameraCaptureUIMode.Photo);
             if (photo != null)
             {
                 CutPicture(photo);//裁剪图片
             }
         }

3.裁剪图片调用的公共方法CutPicture

         /// <summary>
         /// 1.4 裁剪图片
         /// </summary>
         /// <param name="file"></param>
         public async void CutPicture(StorageFile file)
         {
             #region 裁剪图片
             var inputFile = SharedStorageAccessManager.AddFile(file);//  获取一个文件共享Token,使应用程序能够与另一个应用程序共享指定的文件。
             var destination = await ApplicationData.Current.LocalFolder.CreateFileAsync("Cropped.jpg", CreationCollisionOption.ReplaceExisting);//在应用文件夹中建立文件用来存储裁剪后的图像
             var destinationFile = SharedStorageAccessManager.AddFile(destination);
             var options = new LauncherOptions();
             options.TargetApplicationPackageFamilyName = "Microsoft.Windows.Photos_8wekyb3d8bbwe";//应用于启动文件或URI的目标包的包名称
             //待会要传入的参数
             var parameters = new ValueSet();
             parameters.Add("InputToken", inputFile);                //输入文件
             parameters.Add("DestinationToken", destinationFile);    //输出文件
             parameters.Add("ShowCamera", false);                    //它允许我们显示一个按钮，以允许用户采取当场图象(但是好像并没有什么用)
             parameters.Add("EllipticalCrop", true);                 //截图区域显示为圆（最后截出来还是方形）
             parameters.Add("CropWidthPixals", );
             parameters.Add("CropHeightPixals", );
             //调用系统自带截图并返回结果
             var result = await Launcher.LaunchUriForResultsAsync(new Uri("microsoft.windows.photos.crop:"), options, parameters);
             if (result.Status == LaunchUriStatus.Success && result.Result != null)
             {
                 //对裁剪后图像的下一步处理
                 try
                 {
                     // 载入已保存的裁剪后图片
                     var stream = await destination.OpenReadAsync();
                     var bitmap = new BitmapImage();
                     await bitmap.SetSourceAsync(stream);
                       // 显示裁剪过后的图片
                     imglogo.ImageSource = bitmap;
                     //此方法是请求后台修改图片
                     SetHeadPicture(destination);
                     OutBorder.Visibility = Visibility.Collapsed;
                 }
                 catch (Exception ex)
                 {
                     System.Diagnostics.Debug.WriteLine(ex.Message + ex.StackTrace);
                 }
             }
             #endregion
         }

4.使用Windows.Web.Http命名空间下的HttpClient使用post方法，上传图片服务器

参考:https://social.msdn.microsoft.com/Forums/zh-CN/ec0ffd44-f7a6-4a53-8f8e-d15e13cfa5fb/windowswebhttphttpclientpost?forum=winstoreappzhcn

我的做法是将需要上传的参数放在HttpMultipartFormDataContent中,然后再使用HttpClient的PostAsync进行提交

请求参数:

        /// <summary>
         /// 向服务器发送post请求(修改头像)
         /// </summary>
         /// <param name="url">路径</param>
         /// <returns></returns>
         public async static Task<string> SendPostRequest(string url)
         {
             try
             {
                 Dictionary<string, object> dic = new Dictionary<string, object>();
                 dic.Add("GWnumber", setHeadPicture.GWnumber);
                 dic.Add("token", setHeadPicture.Token);
                 dic.Add("file", setHeadPicture.File);//file值是StorageFile类型
                 dic.Add("systemType", setHeadPicture.SystemType);

                 HttpMultipartFormDataContent form = new HttpMultipartFormDataContent();
                 foreach (KeyValuePair<string, object> item in dic)
                 {
                     if (item.Key == "file")
                     {
                         StorageFile file = item.Value as StorageFile;
                         HttpStreamContent streamContent = new HttpStreamContent(await file.OpenReadAsync());
                         form.Add(streamContent, item.Key, "file.jpg");//注意:这里的值是必须的,图片所以使用的是HttpStreamContent
                     }
                     else
                     {
                         form.Add(new HttpStringContent(item.Value + ""), item.Key);
                     }
                 }
                 HttpClient httpClient = new HttpClient();
                 HttpResponseMessage response = await httpClient.PostAsync(new Uri(url), form).AsTask();
                 var contentType = response.Content.Headers.ContentType;
                 if (string.IsNullOrEmpty(contentType.CharSet))
                 {
                     contentType.CharSet = "utf-8";
                 }
                 return await response.Content.ReadAsStringAsync();

             }
             catch (Exception ex)
             {
                 throw ;
             }
         }

uwp小白,请多指教!!