通過TCP（VB.NET）發送字符串

Question

我使用TCP客戶端成功連接到onlinenic API，但在嘗試登錄時面臨錯誤。

下面是我的代碼（用戶名和密碼演示如被OnlineNIC公司提供）

Imports System 
    Imports System.Net.Sockets 
    Imports System.Text 
Imports System.Security.Cryptography 
Imports System.IO 
Imports System.Text.RegularExpressions 
Imports System.Configuration 
Imports System.Xml.Linq 
Imports System.Xml 

Partial Public Class _Default 
    Inherits System.Web.UI.Page 
    Private client As New TcpClient() 
    Private stream As NetworkStream 
    Private PortNo As Integer = 30009 
    Private testIP As String = "218.5.81.149" 
    Private testID As String = "135610" 
    Private testPassword As String = "654123" 
    Private Function Connect() As Boolean 
     client.Connect(testIP, PortNo) 
     stream = client.GetStream() 
     Dim responseData As String = "" 
     Dim data As [Byte]() = New [Byte](255) {} 
     Dim bytes As Int32 = stream.Read(data, 0, data.Length) 
     responseData = Encoding.ASCII.GetString(data, 0, bytes) 
     Return responseData.Contains("Your Connection with API Server is Successful") 
    End Function 




    Private Function Login() As Boolean 
     Dim HashedPass As String = CreateMd5Hash(testPassword) 
     Dim guid__1 As Guid = Guid.NewGuid() 
     Dim chksum As String = CreateMd5Hash(testID + HashedPass + guid__1.ToString() + "login") 
     Dim sb As New StringBuilder() 
     sb.Append("<?xml version=""1.0"" encoding=""UTF-8"" standalone=""no""?>") 
     sb.Append("<request>") 
     sb.Append("<category>client</category>") 
     sb.Append("<action>Login</action>") 
     sb.Append("<params>") 
     sb.Append("<param name=""clid"">" + testID + "</param>") 
     sb.Append("</params>") 
     sb.Append("<cltrid>" + guid__1.ToString() + "</cltrid>") 
     sb.Append("<chksum>" + chksum + "</chksum>") 
     sb.Append("</request>") 
     Dim responseData As [String] = [String].Empty 
     Dim data As [Byte]() 
     data = System.Text.Encoding.ASCII.GetBytes(sb.ToString()) 
     stream.Write(data, 0, data.Length) 
     Dim bytes As Int32 = stream.Read(data, 0, data.Length) 
     responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes) 
     bytes = stream.Read(data, 0, data.Length) 
     responseData += System.Text.Encoding.ASCII.GetString(data, 0, bytes) 
     Return responseData.Contains("Command completed successfully") 
    End Function 

當我嘗試使用我有以下錯誤上述login（）函數來連接：

對象未將引用設置爲對象的實例。

Line 49:   Dim data As [Byte]() 
Line 50:   data = System.Text.Encoding.ASCII.GetBytes(sb.ToString()) 
Line 51:   stream.Write(data, 0, data.Length) 
Line 52:   Dim bytes As Int32 = stream.Read(data, 0, data.Length) 
Line 53:   responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes) 

該錯誤消息正在逐漸在這條線：stream.Write（數據1,0，data.Length）

System.NullReferenceException是由用戶代碼未被設置
消息= Object引用未處理到一個對象的一個​​實例。
源= App_Web_4023pkvf堆棧跟蹤：在d 在_Default.Login（）：\ Documents和Settings \ SA \我的文檔\的Visual Studio 2010 \網站已\ onlinenic_vb1 \ Default.aspx.vb：線51 在_Default.Button2_Click（對象發件人，EventArgs e）在D：\ Documents and Settings \ sa \ My Documents \ Visual Studio 2010 \ WebSites \ onlinenic_vb1 \ Default.aspx.vb：行243 在System.Web.UI.WebControls.Button.OnClick（ EventArgs的） 在System.Web.UI.WebControls.Button.RaisePostBackEvent（字符串eventArgument） 在System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent（字符串 eventArgument） 在系統。 Web.UI.Page.RaisePostBackEvent（IPostBackEventHand LER sourceControl，字符串eventArgument） 在System.Web.UI.Page.RaisePostBackEvent（NameValueCollection中POSTDATA） 在System.Web.UI.Page.ProcessRequestMain（布爾includeStagesBeforeAsyncPoint，布爾includeStagesAfterAsyncPoint）
的InnerException：

Answer 1

你應該試試這個：

Dim HashedPass As String = CreateMd5Hash(testPassword) 
     Dim guid__1 As Guid = Guid.NewGuid() 
     Dim chksum As String = CreateMd5Hash(testID + HashedPass + guid__1.ToString() + "login") 
     Dim sb As New StringBuilder() 
     sb.Append("<?xml version=""1.0"" encoding=""UTF-8"" standalone=""no""?>") 
     sb.Append("<request>") 
     sb.Append("<category>client</category>") 
     sb.Append("<action>Login</action>") 
     sb.Append("<params>") 
     sb.Append("<param name=""clid"">" + testID + "</param>") 
     sb.Append("</params>") 
     sb.Append("<cltrid>" + guid__1.ToString() + "</cltrid>") 
     sb.Append("<chksum>" + chksum + "</chksum>") 
     sb.Append("</request>") 
     Dim responseData As [String] = [String].Empty 
     Dim data As [Byte]() 
     data = System.Text.Encoding.ASCII.GetBytes(sb.ToString()) 
     stream.Write(data, 0, data.Length) 
     Dim bytes As Int32 = stream.Read(data, 0, data.Length) 
     responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes) 
     bytes = stream.Read(data, 0, data.Length) 
     responseData += System.Text.Encoding.ASCII.GetString(data, 0, bytes) 
     Return responseData.Contains("Command completed successfully")