必須聲明標量變量「@User_Name」

Question

參照我的最後一個問題：「The connection was not closed. The connection's current state is open」。我正在嘗試使用ASP.NET的vb.net做一個註冊表單。解決了有關「密切聯繫」的問題後。我有問題將數據插入到我的數據庫。當我嘗試驗證它給我一個錯誤消息中的數據：

必須聲明標量變量「@User_Name」

有人可以幫我調試這個？謝謝

Imports System.Data 
    Imports System.Configuration 
    Imports System.Data.SqlClient 
    Partial Class Register2 

Inherits System.Web.UI.Page 

'declaring connection string and command 
'here we are extracting connection string from web.config file 
Private con As New SqlConnection(ConfigurationManager.ConnectionStrings("MauriAuctions").ToString()) 
Private cmd As New SqlCommand() 

Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click 
    Try 
     cmd.Connection = con 
     'assigning connection to command 
     cmd.CommandType = CommandType.Text 
     'representing type of command 
     'cmd.CommandText = "INSERT INTO UserDetails (User_Name,Fname,Lname,Email,Password,Gender,Dob,Mobile,Address) values 
     ' (@User_Name,@Fname,@Lname,@Email,@Password,@Gender,@Dob,@Mobile,@Address)"; 
     cmd.CommandText = "INSERT INTO tbl_user (User_Name, Fname, Lname, Email, Pwd, Street, Town, City, Tel) values(@User_Name,@Fname,@Lname,@Email,@Pwd,@Street,@Town,@City,@Tel)" 

     'adding parameters with value 

     cmd.Parameters.AddWithValue("@User_Name", txtUser_Name.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Fname", txtFirstName.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Lname", txtLastName.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Email", txtEmail.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Pwd", txtPassword.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Street", txtStreet.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Town", txtTown.Text.ToString()) 
     cmd.Parameters.AddWithValue("@City", txtCity.Text.ToString()) 
     cmd.Parameters.AddWithValue("@Tel", txtTel.Text.ToString()) 
     cmd.Parameters.Clear() 

     con.Open() 
     'opening connection 
     cmd.ExecuteNonQuery() 
     'executing query 
     con.Close() 
     'closing connection 

     lblMsg.Text = "Registered Successfully.." 

    Catch ex As Exception 
     lblMsg.Text = ex.Message.ToString() 

    Finally 

     con.Close() 
     'closing connection 
    End Try 
End Sub 

Protected Sub btnClear_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClear.Click 
    'refreshing/reloading page to clear all the controls 
    Page.Response.Redirect(Page.Request.Url.ToString(), True) 
End Sub 
    End Class 

Answer 1

您在添加它們之後清除參數。嘗試在cmd.Parameters.Clear()之前先.AddWithValue,而不是之後最後一個。