c＃smartdevice - HTTPWEBREQUEST GET與POST InvalidOperationException

Question

在下面的代碼中，DoGet工作非常穩定。但DoPost隨機拋出一個不可撤銷的InvalidOperationException。我搞不清楚了。任何指針都會有巨大的幫助。

/* 
    Environment 
    ------------- 
    * NET CF 2.0 
    * WM 5.0(USA Mobile Pocket PC Emulator) 
    * Windows XP Professional SP2 
    * VS 2008 
*/ 

/* 
    The exception 
    ------------------ 
    at System.Net.HttpWebRequest.set_ContentLength(Int64 value) 
    at System.Net.HttpWebRequest.BufferConnectStream.WritingSucceeds() 
    at System.Net.HttpWriteStream.doClose() 
    at System.Net.HttpWriteStream.Finalize() 
*/ 

public static string DoPost(string url) 
{ 
    // initialize from variables 
    string responseString = string.Empty; 
    ASCIIEncoding encoding = new ASCIIEncoding(); 
    HttpWebResponse response; 
    byte[] data = encoding.GetBytes("dummy"); 
    StreamReader reader; 
    HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); 

    //do the processing 
    SetRequestProperties(request, "POST"); // SETTING METHOD TO POST HERE 
    request.GetRequestStream().Write(data, 0, data.Length); 
    request.GetRequestStream().Close(); 
    response = (HttpWebResponse)request.GetResponse(); 
    reader = new StreamReader(response.GetResponseStream()); 
    responseString = reader.ReadToEnd(); 

    //clean up 
    response.Close(); 
    response.GetResponseStream().Close(); 
    response.GetResponseStream().Dispose(); 
    reader.Close(); 
    reader.Dispose(); 
    reader = null; 
    response = null; 
    request = null; 
    encoding = null; 

    //return 
    MessageBox.Show("POST SUCCESS"); 
    return responseString; 

} 

public static string DoGet(string url) 
{ 
    // initialize from variables 
    string responseString = string.Empty; 
    ASCIIEncoding encoding = new ASCIIEncoding(); 
    HttpWebResponse response; 
    byte[] data = encoding.GetBytes("dummy"); 
    StreamReader reader; 
    HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url); 

    //do the processing 
    SetRequestProperties(request, "GET"); // SETTING METHOD TO GET HERE 
    response = (HttpWebResponse)request.GetResponse(); 
    reader = new StreamReader(response.GetResponseStream()); 
    responseString = reader.ReadToEnd(); 

    //clean up 
    response.Close(); 
    response.GetResponseStream().Close(); 
    response.GetResponseStream().Dispose(); 
    reader.Close(); 
    reader.Dispose(); 
    reader = null; 
    response = null; 
    request = null; 
    encoding = null; 

    //return 
    MessageBox.Show("GET SUCCESS"); 
    return responseString; 

} 

private static void SetRequestProperties(HttpWebRequest request, string s) 
{ 
    request.Method = s; 
    request.AllowWriteStreamBuffering = true; 
    request.KeepAlive = false; 
    request.ContentType = "application/x-www-form-urlencoded"; 
    request.SendChunked = false; 
    request.Credentials = CredentialCache.DefaultCredentials; 
    request.UserAgent = "my mobile user agent"; 
    request.Timeout = 60000; 
    request.ProtocolVersion = new System.Version("1.1"); 
} 

Answer 1

這與下面鏈接link text？