wr.UserAgent = @"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; Maxthon; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";

DateTime CurrTime = DateTime.Now;
string qtyUpdType = "UpdateQty";
string partNumber = "TEST_123";
string productQuantity = "500";
string productDateCode = "2006+";
string productManufacturer = "IBM";
string productDescription = "Some description";
string productPrice = "100.99";
 

string PostString= @"MIME-Version: 1.0
                    Content-type: Multipart/Related; boundary=""MTO-part-boundary""; type=""application/mto-agent"" =
                    Content-Description: Business document
                    --MTO-part-boundary 
                    Content-type: text/xml 
                    Content-Description: Header 
                    <?xml version = ""1.0""?> 
                    <!DOCTYPE MTOHeader SYSTEM ""MTOHeader.dtd""> 
                    <MTOHeader> 
                            <MTOCode>InventoryUpdate</MTOCode> 
                            <MTOVersion>1.0</MTOVersion> 
                            <MessageInstanceId>123</MessageInstanceId> 
                            <InReplyTo/>  
                            <ActionCode>Action</ActionCode>  
                            <DateTime>" + CurrTime.ToString("dd/MM/yyyy") + "</DateTime>" +
                    @"
                    </MTOHeader> 
 
                    --MTO-part-boundary 
                    Content-type: text/xml 
                    Content-Description: Content 
                    <?xml version = ""1.0""?> 
                    <!DOCTYPE CmInventoryUpdateRequest SYSTEM ""CmInventoryUpdateRequest.dtd""> 
                    <CmInventoryUpdateRequest qtyUpdType=""" + qtyUpdType + @""">" +
                        @"
                        <Items>
                            <Item operation=""ADD""> 
                                <PartNumber>" + partNumber + "</PartNumber>" +
                                @"
                                <Manufacturer>" + productManufacturer + "</Manufacturer>" + 
                                @"
                                <Description>" + productDescription + "</Description>" + 
                                @"
                                <DateCode>" + productDateCode + "</DateCode>" +
                                @"
                                <MemberPrice>" + productPrice + "</MemberPrice>" +
                                @"
                                <Quantity>" + productQuantity + "</Quantity>" +
                                @"
                            </Item> 
                         </Items>
                    </CmInventoryUpdateRequest> 
                    --MTO-part-boundary--;";
 

//2- Create a HTTP connection to the server test.brokerforum.com (testing environment) or xml.brokerforum.com (prod environment).
 
//Example :
System.Net.HttpWebRequest wr = (HttpWebRequest)HttpWebRequest.Create("http://xml.brokerforum.com");
 

//3- Set headers.  Note that the username and password must be encrypted using 64 base encoding
//Example :

string UserName = "zhu_XML";
string Password = "dev123";
 

wr.KeepAlive = true;
wr.Headers = new WebHeaderCollection();
wr.Method = "POST";
wr.ContentType = "application/mto-agent";
//wr.UserAgent = UserAgent;
wr.UserAgent = @"Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; Maxthon; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
wr.ContentLength = PostString.Length;
string base64EncodedAuthorizationString = UserName + ":" + Password;
byte[] binaryData = new Byte[base64EncodedAuthorizationString.Length];
binaryData = Encoding.UTF8.GetBytes(base64EncodedAuthorizationString);
base64EncodedAuthorizationString = Convert.ToBase64String(binaryData);
base64EncodedAuthorizationString = "Basic " +
base64EncodedAuthorizationString;
wr.Headers.Add("Authorization", base64EncodedAuthorizationString);
 

//4- Get the request stream from the HttpWebRequest
 
//Example : 
Stream requestStream = wr.GetRequestStream();
//byte[] bs = Encoding.ASCII.GetBytes(PostString);

//using (Stream requestStream = wr.GetRequestStream())
//{
//    requestStream.Write(bs, 0, bs.Length);
//}


//Encoder encode;

//byte[] bytes = encode.GetBytes(PostString);
byte[] bytes = Encoding.Default.GetBytes(PostString);
requestStream.Write(bytes, 0, bytes.Length);
bytes.Clone();
bytes = null;
            
//5- Get the response from the server
 
//Example :
 
HttpWebResponse response = null;
response = (HttpWebResponse)wr.GetResponse(); // 出错的地方 提示 "远程服务器返回错误: (500) 内部服务器错误。" 
 
Stream responseStream = response.GetResponseStream();
 
wr = null;
 
// Print the response for debugging purposes
Console.WriteLine(responseStream.ToString());

// Create a new 'HttpWebRequest' object to the mentioned URL.
HttpWebRequest myHttpWebRequest=(HttpWebRequest)WebRequest.Create("http://www.contoso.com");
myHttpWebRequest.UserAgent=".NET Framework Test Client";
// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
HttpWebResponse myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();
// Display the contents of the page to the console.
Stream streamResponse=myHttpWebResponse.GetResponseStream();
StreamReader streamRead = new StreamReader( streamResponse );
Char[] readBuff = new Char[256];
int count = streamRead.Read( readBuff, 0, 256 );
Console.WriteLine("\nThe contents of HTML Page are :\n");    
while (count > 0) 
{
    String outputData = new String(readBuff, 0, count);
    Console.Write(outputData);
    count = streamRead.Read(readBuff, 0, 256);
}
// Release the response object resources.
streamRead.Close();
streamResponse.Close();
myHttpWebResponse.Close();