Question

我正在将一个图像文件从windows phone 7平台发布到远程服务器。为此，我首先使用photochoosertask将图像保存到隔离存储中以便进一步访问。为了保存，我使用了以下代码：

using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
{
    if (isf.FileExists("myimage.jpg"))
        isf.DeleteFile("myimage.jpg");

    using (IsolatedStorageFileStream isfs = isf.CreateFile("myimage.jpg"))
    {
        var bmp = new WriteableBitmap(56, 56);
        bmp.SaveJpeg(isfs, bmp.PixelWidth, bmp.PixelHeight, 0, 100);
    }
}

之后我使用以下代码发布文件：

private void UploadFilesToRemoteUrl(string url, string files, string logpath1)
{

    long length = 0;
    string boundary = "----------------------------" +
    DateTime.Now.Ticks.ToString("x");


    HttpWebRequest httpWebRequest2 = (HttpWebRequest)WebRequest.Create(url);
    httpWebRequest2.ContentType = "multipart/form-data; boundary=" + boundary;
    httpWebRequest2.Method = "POST";
  //  httpWebRequest2.KeepAlive = true;

    //httpWebRequest2.Credentials =
    //System.Net.CredentialCache.DefaultCredentials;

    Stream memStream = new System.IO.MemoryStream();

    byte[] boundarybytes = System.Text.Encoding.UTF8.GetBytes("\r\n--" +
    boundary + "\r\n");


    memStream.Write(boundarybytes, 0, boundarybytes.Length);
    length += boundarybytes.Length;

    string headerTemplate = "Content-Disposition: form-data; name=\"{0}\";filename=\"{1}\"\r\n Content-Type: application/octet-stream\r\n\r\n";

    string header = string.Format(headerTemplate, "file", files);

    byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);

    memStream.Write(headerbytes, 0, headerbytes.Length);
    length += headerbytes.Length;
    char[] ch = new char[1];
    ch[0] = '\\';
    string[] flname = filename.Split(ch);
   // FileStream fileStream = new FileStream(files, FileMode.Open, FileAccess.Read);
    var store = IsolatedStorageFile.GetUserStoreForApplication();

    //IsolatedStorageFileStream fileStream = new IsolatedStorageFileStream(flname[6], FileMode.Open, store);
    System.IO.IsolatedStorage.IsolatedStorageFileStream fileStream = new IsolatedStorageFileStream(flname[6], FileMode.Open, store);


    byte[] buffer = new byte[1024];

    int bytesRead = 0;

    while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
    {
        memStream.Write(buffer, 0, bytesRead);
        length += bytesRead;
    }

    memStream.Write(boundarybytes, 0, boundarybytes.Length);
    length += boundarybytes.Length;

    fileStream.Close();

    //httpWebRequest2.ContentLength = memStream.Length;

    Stream requestStream = httpWebRequest2.GetRequestStream();

    memStream.Position = 0;
    byte[] tempBuffer = new byte[memStream.Length];
    memStream.Read(tempBuffer, 0, tempBuffer.Length);
    memStream.Close();
    requestStream.Write(tempBuffer, 0, tempBuffer.Length);
    requestStream.Close();


    WebResponse webResponse2 = httpWebRequest2.GetResponse();

    Stream stream2 = webResponse2.GetResponseStream();
    StreamReader reader2 = new StreamReader(stream2);

   //MessageBox.Show(reader2.ReadToEnd());

    webResponse2.Close();
    httpWebRequest2 = null;
    webResponse2 = null;
}

但是我收到回复的错误，我从WebResponse webResponse2 = httpWebRequest2.GetResponse();得到的回复为空。

请帮帮我。

Answer 1

你必须异步做任何事情。这是一个小例子：

public WebrequestExample()
{
    string url = "COPY YOUR URL HERE";
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

    // ...
    // Different settings, like content type or method...
    // ...

    request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request);
}

public void GetRequestStreamCallback(IAsyncResult asyncResult)
{
    HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
    Stream postStream = request.EndGetRequestStream(asyncResult);

    // Data writing
    // ...
    // postStream.Write(...)
    // ...

    // Start the async operation to get the response
    request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
}

public void GetResponseCallback(IAsyncResult asyncResult)
{
    HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
    HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asyncResult); // Get the HttpWebResponse

    using (var stream = response.GetResponseStream())
    {
        using (var reader = new StreamReader(stream))
        {
            // Do something with the response
        }
    }
}

使用HttpWebRequest发布图像文件时出现问题

1 个答案: