Must declare the scalar variable "#Name" - asp.net

Question

I have these includes:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
My connection string is
public partial class Directory : System.Web.UI.Page
{
SqlConnection con = new SqlConnection("Data Source=10.4.33.61;Initial Catalog=Bank_Reconciliation;Persist Security Info=True;User ID=****;Password=****");
protected void Page_Load(object sender, EventArgs e)
{
}
My method to search by string and display in data grid view (naming search button as btnsearch) is
protected void btnsearch_Click(object sender, EventArgs e)
{
string str = "select * from Employee where (Name like '%' + #search + '%') ";
SqlCommand xp = new SqlCommand(str, con);
xp.Parameters.Add("#search", SqlDbType.VarChar).Value = txtsearch.Text;
con.Open();
xp.ExecuteNonQuery();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = xp;
DataSet ds = new DataSet();
da.Fill(ds,"Name");
GridView1.DataSource = ds;
GridView1.DataBind();
con.Close();
}
}
I receive the following error:
Must declare the scalar variable "#Name".
Why is this, and how do I fix it?

Answer 1

It might be easier to have the TSQL just use LIKE #search, and handle it when adding the parameter:
protected void btnsearch_Click(object sender, EventArgs e)
{
string str = #"SELECT * FROM Employee WHERE Name LIKE #search";
SqlCommand xp = new SqlCommand(str, con);
xp.Parameters.AddWithValue("#search", "%" + txtSearch.Text + "%");
con.Open();
xp.ExecuteNonQuery();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = xp;
DataSet ds = new DataSet();
da.Fill(ds,"Name");
GridView1.DataSource = ds;
GridView1.DataBind();
con.Close();
}

Answer 2

Change you button click code to this:
protected void btnsearch_Click(object sender, EventArgs e)
{
string str = "select * from Employee where (Name like '%" + #search + "%') ";
SqlCommand xp = new SqlCommand(str, con);
xp.Parameters.Add("#search", SqlDbType.VarChar).Value = txtsearch.Text;
con.Open();
xp.ExecuteNonQuery();
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = xp;
DataTable dt = new DataTable();
da.Fill(ds, dt);
GridView1.DataSource = dt;
GridView1.DataBind();
con.Close();
}
}
It puts proper quotes for like operator, and also used DataTable instead of DataSet. You can also use DataSet but here it seems no need for that.