仿QQ聊天的代码。在打开聊天窗口并输入聊天内容执行发送时，程序报错：

xwcuit 2015-11-07 01:26:43

参数化查询 '(@FromUserId int,@ToUserId int,@Message nvarchar(1),@MessageType' 需要参数 '@MessageState'，但未提供该参数。

错误详细信息为：

未处理 System.Data.SqlClient.SqlException
Message="参数化查询 '(@FromUserId int,@ToUserId int,@Message nvarchar(1),@MessageType' 需要参数 '@MessageState'，但未提供该参数。"
Source=".Net SqlClient Data Provider"
ErrorCode=-2146232060
Class=16
LineNumber=0
Number=8178
Procedure=""
Server="(local)"
State=1
StackTrace:
在 System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
在 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
在 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
在 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
在 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
在 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
在 System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
在 DAL.SqlHelper.ExecuteNonQuery(String connectionString, CommandType cmdType, String cmdText, SqlParameter[] commandParameters) 位置 D:\BOOK\C#_code\project\QQ2010\DAL\SQLHelper.cs:行号 54
在 DAL.MessagesDAL.Insert(MessagesInfo entity) 位置 D:\BOOK\C#_code\project\QQ2010\DAL\MessagesDAL.cs:行号 122
在 BLL.Messages.SendMessage(MessagesInfo entity, EnumMessageType messageType) 位置 D:\BOOK\C#_code\project\QQ2010\BLL\Messages.cs:行号 84
在 MyQQ.frmChat.btnSend_Click(Object sender, EventArgs e) 位置 D:\BOOK\C#_code\project\QQ2010\MyQQ\frmChat.cs:行号 77
在 System.Windows.Forms.Control.OnClick(EventArgs e)
在 System.Windows.Forms.Button.OnClick(EventArgs e)
在 System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
在 System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
在 System.Windows.Forms.Control.WndProc(Message& m)
在 System.Windows.Forms.ButtonBase.WndProc(Message& m)
在 System.Windows.Forms.Button.WndProc(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
在 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
在 System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
在 System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
在 System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
在 System.Windows.Forms.Application.Run(Form mainForm)
在 MyQQ.Program.Main() 位置 D:\BOOK\C#_code\project\QQ2010\MyQQ\Program.cs:行号 17
在 System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
在 System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
在 Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
在 System.Threading.ThreadHelper.ThreadStart_Context(Object state)
在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
在 System.Threading.ThreadHelper.ThreadStart()
InnerException:

具体代码如下：

using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Collections;

namespace DAL
{
public class SqlHelper
{

public static readonly string ConnString = ConfigurationManager.ConnectionStrings["SQLConnString"].ConnectionString;

// Hashtable to store cached parameters
private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{

SqlCommand cmd = new SqlCommand();

using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}
}

public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{

SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}

public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return val;
}

public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();
SqlConnection conn = new SqlConnection(connectionString);

try
{
PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return rdr;
}
catch
{
conn.Close();
throw;
}
}

public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{
SqlCommand cmd = new SqlCommand();

using (SqlConnection connection = new SqlConnection(connectionString))
{
PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}
}

public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
{

SqlCommand cmd = new SqlCommand();

PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
object val = cmd.ExecuteScalar();
cmd.Parameters.Clear();
return val;
}

public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
{
parmCache[cacheKey] = commandParameters;
}

public static SqlParameter[] GetCachedParameters(string cacheKey)
{
SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

if (cachedParms == null)
return null;

SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

for (int i = 0, j = cachedParms.Length; i < j; i++)
clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

return clonedParms;
}

private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();

cmd.Connection = conn;
cmd.CommandText = cmdText;

if (trans != null)
cmd.Transaction = trans;

cmd.CommandType = cmdType;

if (cmdParms != null)
{
foreach (SqlParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
}
}

请教高手如何解决？谢谢。

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