从对象类型System.Web.UI.WebControls.TextBox到已知的托管提供程序本机类型不存在映射

Question

这是我的代码

SqlCommand cmd = new SqlCommand("spRegisterUser", con);
cmd.CommandType = CommandType.StoredProcedure;

SqlParameter username = new SqlParameter("@UserName", txtUserName.Text);

SqlParameter password = new SqlParameter("@Password", txtPassword);
SqlParameter email = new SqlParameter("@Email", txtEmail.Text);
SqlParameter userType = new SqlParameter("@UserType", SqlDbType.NVarChar, 200);
userType.Value = "Student";
cmd.Parameters.Add(username);
cmd.Parameters.Add(password);
cmd.Parameters.Add(email);
cmd.Parameters.Add(userType);

con.Open();

int ReturnCode = (int)cmd.ExecuteScalar(); //This is where it displays error message
if (ReturnCode == -1)

有任何想法吗？

这是错误消息

 No mapping exists from object type System.Web.UI.WebControls.TextBox to a known managed provider native type.

描述:执行当前Web请求期间发生未处理的异常.请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息.

Exception Details: System.ArgumentException: No mapping exists from object type System.Web.UI.WebControls.TextBox to a known managed provider native type.

Source Error:


Line 48:                     con.Open();
Line 49: 
Line 50:                     int ReturnCode = (int)cmd.ExecuteScalar();
Line 51:                     if (ReturnCode == -1)
Line 52:                     {


    Source File: c:\Users\Mubashir\Documents\Visual Studio 2012\Projects\Sit302GroupProject\Sit302GroupProject\Registration\Registration.aspx.cs    Line: 50

    Stack Trace:


    [ArgumentException: No mapping exists from object type System.Web.UI.WebControls.TextBox to a known managed provider native type.]
       System.Data.SqlClient.MetaType.GetMetaTypeFromValue(Type dataType, Object value, Boolean inferLen, Boolean streamAllowed) +2021139
       System.Data.SqlClient.SqlParameter.GetMetaTypeOnly() +5287377
       System.Data.SqlClient.SqlParameter.Validate(Int32 index, Boolean isCommandProc) +16
       System.Data.SqlClient.SqlCommand.SetUpRPCParameters(_SqlRPC rpc, Int32 startCount, Boolean inSchema, SqlParameterCollection parameters) +122
       System.Data.SqlClient.SqlCommand.BuildRPC(Boolean inSchema, SqlParameterCollection parameters, _SqlRPC& rpc) +78
       System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) +1379
       System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +175
       System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +53
       System.Data.SqlClient.SqlCommand.ExecuteScalar() +149
       Sit302GroupProject.Registration.btnRegister_Click(Object sender, EventArgs e) in c:\Users\Mubashir\Documents\Visual Studio 2012\Projects\Sit302GroupProject\Sit302GroupProject\Registration\Registration.aspx.cs:50
       System.Web.UI.WebControls.Button.OnClick(EventArgs e) +9552602
       System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +103
       System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
       System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
       System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35
       System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1724

这是存储过程

    CREATE proc spRegisterUser
@Username nvarchar(100),
@Password nvarchar(200),
@Email  nvarchar(200),
@UserType  nvarchar(200),
as 
Begin 
Declare @Count int
Declare @ReturnCode int

Select @Count = COUNT(UserName)
from tblUsers where UserName = @UserName
If @COunt > 0
Begin 
Set @Return = -1
End
Else
Begin
Set @ReturnCode = 1
Insert into tblUsers values
(@UserName, @Password, @Email, @UserType)
End
Select @ReturnCode as ReturnValue
End

Answer 1

您传递的txtPassword是TextBox的对象,因此您将获得异常.

问题是符合的

SqlParameter password = new SqlParameter("@Password", txtPassword);

所以将代码更改为

SqlParameter password = new SqlParameter("@Password", txtPassword.Text);