1.这里有一些问题，我无法找到它抛出异常的原因，因为我已经连接了我的 SQL SERVER MANAGEMENT STUDIO 2. 我正在制作一个用户注册 Webform 页面，当我尝试运行代码并填写所有详细信息时发生了这种情况请帮忙。

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using system.web;
using system.web.UI;
using system.web.UI.WebControls;

namespace Relocations
{
   public partial class SignUp : system.web.UI.Page
   {
        String strcon = Configurationmanager.ConnectionStrings["con"].ConnectionString;
        protected void Page_Load(object sender,EventArgs e)
        {
            
        }

        protected void Button1_Click(object sender,EventArgs e)
        {
            if (checkMemberExists())
            {
                Response.Write("<script>alert('Member Id already Exist');</script>");
            }
            else
            {
                signUpNewMember();
            }
        }
            bool checkMemberExists()
            {
                try
                    {
                        SqlConnection con = new SqlConnection(strcon);
                        if (con.State == ConnectionState.Closed)
                        {
                            con.Open();
                        }
                        SqlCommand cmd = new SqlCommand("SELECT * from member_master_tb1 where member_id='" + TextBox8.Text.Trim() + "';",con);
                        SqlDataAdapter da = new SqlDataAdapter(cmd);
                        DataTable dt = new DataTable();
                        da.Fill(dt);
                        if (dt.Rows.Count >= 1) 
                        {
                            return true;
                        }
                        else 
                        {
                            return false;
                        }
              
                    }
                catch (Exception ex)
                {
                    Response.Write("<script>alert('" + ex.Message + "');</script>");
                    return false;
                }
            
            }  

            void signUpNewMember()
            {
                try
                {
                    SqlConnection con = new SqlConnection(strcon);
                    if (con.State == ConnectionState.Closed)
                    {
                        con.Open();
                    }
                    SqlCommand cmd = new SqlCommand("INSERT INTO member_master_tb1(full name,dob,contact,email,state,city,pincode,address,member_id,password,account_status) value(@full name,@dob,@contact,@email,@state,@city,@pincode,@address,@member_id,@password,@account_status)",con);
                    cmd.Parameters.AddWithValue("@full name",TextBox3.Text.Trim());
                    cmd.Parameters.AddWithValue("@dob",TextBox4.Text.Trim());
                    cmd.Parameters.AddWithValue("@contact",TextBox1.Text.Trim());
                    cmd.Parameters.AddWithValue("@email",TextBox2.Text.Trim());
                    cmd.Parameters.AddWithValue("@state",DropDownList1.SelectedItem.Value);
                    cmd.Parameters.AddWithValue("@city",TextBox5.Text.Trim());
                    cmd.Parameters.AddWithValue("@pincode",TextBox6.Text.Trim());
                    cmd.Parameters.AddWithValue("@address",TextBox7.Text.Trim());
                    cmd.Parameters.AddWithValue("@member_id",TextBox8.Text.Trim());
                    cmd.Parameters.AddWithValue("@password",TextBox9.Text.Trim());
                    cmd.Parameters.AddWithValue("@account_status","pending");

                    cmd.ExecuteNonQuery();
                    con.Close();
                    Response.Write("<script>alert('Sign Up Successfully. Ypu can Login Now');</script>");
                }
                catch (Exception ex)
                {

Response.Write("<script>alert('" + ex.Message + "')</script>");
---------------------------------------------------------------

                }
            }
        
    }
}