使用C＃和WebRequest上传图像？

Question

这里是用Python运行的代码（使用卷曲）：

#!/usr/bin/python 

import pycurl 

c = pycurl.Curl() 
values = [ 
      ("key", "YOUR_API_KEY"), 
      ("image", (c.FORM_FILE, "file.png"))] 
# OR:  ("image", "http://example.com/example.jpg"))] 
# OR:  ("image", "BASE64_ENCODED_STRING"))] 

c.setopt(c.URL, "http://imgur.com/api/upload.xml") 
c.setopt(c.HTTPPOST, values) 

c.perform() 
c.close() 

这是我在C＃：

public void UploadImage() 
    { 
     //I think this line is doing something wrong. 
     //byte[] x = File.ReadAllBytes(@"C:\Users\Sergio\documents\visual studio 2010\Projects\WpfApplication1\WpfApplication1\Test\hotness2.jpg"); 

     //If I do it like this, using a direct URL everything works fine. 
     string parameters = @"key=1b9189df79bf3f8dff2125c22834210903&image=http://static.reddit.com/reddit.com.header.png"; //Convert.ToBase64String(x); 
     WebRequest webRequest = WebRequest.Create(new Uri("http://imgur.com/api/upload")); 

     webRequest.ContentType = "application/x-www-form-urlencoded"; 
     webRequest.Method = "POST"; 
     byte[] bytes = Encoding.ASCII.GetBytes(parameters); 

     Stream os = null; 
     try 
     { // send the Post 
      webRequest.ContentLength = bytes.Length; //Count bytes to send 
      os = webRequest.GetRequestStream(); 
      os.Write(bytes, 0, bytes.Length);   //Send it 
     } 
     catch (WebException ex) 
     { 
      MessageBox.Show(ex.Message, "HttpPost: Request error"); 

     } 
     finally 
     { 
      if (os != null) 
      { 
       os.Close(); 
      } 
     } 

     try 
     { // get the response 
      WebResponse webResponse = webRequest.GetResponse(); 

      StreamReader sr = new StreamReader(webResponse.GetResponseStream()); 
      MessageBox.Show(sr.ReadToEnd().Trim()); 
     } 
     catch (WebException ex) 
     { 
      MessageBox.Show(ex.Message, "HttpPost: Response error");     
     }    

    } 

现在，我注意到的事情是，当我改变了我的API密钥参数字符串为“239231”或任何数字，我得到的回应是：“无效的API密钥。”所以我认为一些事情必须是正确的。

我把我的正确 API密钥，现在我得到不同的回应：“无效的图像格式。尝试上传JPEG图像。”

我使用的服务接受几乎所有的图像格式，所以我100％肯定错误是在我发送文件的方式。任何人都可以点亮一下吗？

编辑！

事实证明，当我上传JPG图像时，我得到了灰盒子的东西。如果我上传一张大JPG图片，我什么都没有收到。例如：​​

当我上传PNG时，上传的图片甚至没有显示。

我确定问题是编码。我能做什么？

编辑2！

现在我100％确定问题在于方法的第一行。 File.ReadAllBytes（）必须做错了什么。如果我上传的URL文件，每一个作品桃子：http://imgur.com/sVH61.png

我想知道我应该使用什么编码。 ：S

Answer 1

试试这个：

string file = @"C:\Users\Sergio\documents\visual studio 2010\Projects\WpfApplication1\WpfApplication1\Test\Avatar.png"; 
string parameters = @"key=1df918979bf3f8dff2125c22834210903&image=" + 
    Convert.ToBase64String(File.ReadAllBytes(file)); 

Answer 2

尝试改变： -

"application/x-www-form-urlencoded" 

到

"multipart/form-data" 

Answer 3

尝试添加内容类型为JPG到您的多边界。

查看这个网址的例子（在结束时）

http://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.2

Answer 4

你应该正确地形成多部分POST请求。在这里看一个例子：Upload files with HTTPWebrequest (multipart/form-data)

Answer 5

在黑暗中拍摄，但也许创建一个图像的实例，将文件保存到一个Stream并使用它读取字节到一个数组然后上传它。

如：

Image i = System.Drawing.Image.FromFile("wut.jpg"); 
Stream stm = new Stream(); 
System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality; 
System.Drawing.Imaging.EncoderParameters paramz = new System.Drawing.Imaging.EncoderParameters(1); 
myEncoderParameter = new EncoderParameter(myEncoder, 100L); 
paramz.Param[0] = myEncoderParameter; 
i.Save(stm, System.Drawing.Imaging.ImageFormat.Jpeg, paramz); 
/* I'm lazy: code for reading Stream into byte[] here */ 

Answer 6

读取图像通过API

public IHttpActionResult UpdatePhysicianImage(HttpRequestMessage request) 
    { 
     try 
     { 
      var form = HttpContext.Current.Request.Form; 
      var model = JsonConvert.DeserializeObject<UserPic>(form["json"].ToString()); 
      bool istoken = _appdevice.GettokenID(model.DeviceId); 
      if (!istoken) 
      { 
       statuscode = 0; 
       message = ErrorMessage.TockenNotvalid; 
       goto invalidtoken; 
      } 
      HttpResponseMessage result = null; 
      var httpRequest = HttpContext.Current.Request; 
      if (httpRequest.Files.Count > 0) 
      { 
       var docfiles = new List<string>(); 
       foreach (string file in httpRequest.Files) 
       { 
        var postedFile = httpRequest.Files[file]; 
        // var filePath = uploadPath + postedFile.FileName; 
        // string fileUrl = Utility.AbsolutePath("~/Data/User/" + model.UserId.ToString()); 
        string fileUrl = Utility.AbsolutePath("~/" + Utility.UserDataFolder(model.UserId, "Document")); 
        if (!Directory.Exists(fileUrl)) 
        { 
         Directory.CreateDirectory(fileUrl); 
         Directory.CreateDirectory(fileUrl + "\\" + "Document"); 
         Directory.CreateDirectory(fileUrl + "\\" + "License"); 
         Directory.CreateDirectory(fileUrl + "\\" + "Profile"); 
        } 
        string imageUrl = postedFile.FileName; 
        string naviPath = Utility.ProfileImagePath(model.UserId, imageUrl); 
        var path = Utility.AbsolutePath("~/" + naviPath); 
        postedFile.SaveAs(path); 
        docfiles.Add(path); 
        if (model.RoleId == 2) 
        { 
         var doctorEntity = _doctorProfile.GetNameVideoChat(model.UserId); 
         doctorEntity.ProfileImagePath = naviPath; 
         _doctorProfile.UpdateDoctorUpdProfile(doctorEntity); 
        } 
        else 
        { 
         var patientEntity = _PatientProfile.GetPatientByUserProfileId(model.UserId); 
         patientEntity.TumbImagePath = naviPath; 
         _PatientProfile.UpdatePatient(patientEntity); 
        } 
       } 
       result = Request.CreateResponse(HttpStatusCode.Created, docfiles); 
      } 
      else 
      { 
       result = Request.CreateResponse(HttpStatusCode.BadRequest); 
      } 
     } 
     catch (Exception e) 
     { 
      statuscode = 0; 
      message = "Error" + e.Message; 
     } 
    invalidtoken: 
     return Json(modeldata.GetData(statuscode, message)); 
    }