Windows Form App สอบถามเกี่ยวกับ โค้ด Auto Fill ของ Textbox #VB.Net หน่อยครับ

Import Namespace="System.Data"
Import Namespace="System.Data.SqlClient"

Private Sub txtCode_TextChanged(sender As Object, _ 
  e As EventArgs) Handles txtCode.TextChanged

		Dim objConn As New SqlConnection
		Dim dtAdapter As SqlDataAdapter 
		Dim dt As New DataTable
       
       
		Dim strConnString As String
		strConnString = "Server=localhost;UID=sa;PASSWORD=;database=mydatabase;Max Pool Size=400;Connect Timeout=600;"
		objConn = New SqlConnection(strConnString)
		objConn.Open()

		Dim strSQL As String		
		strSQL = "SELECT * FROM supplier WHERE Code = '" & Me.txtCode.Text & "' "
		
		dtAdapter = New SqlDataAdapter(strSQL, objConn)
		dtAdapter.Fill(dt)

		IF dt.Row.Count > 0 Then
			Me.txtName.Text = dt.Rows(0)("Name").ToString()
			Me.txtAddress.Text = dt.Rows(0)("Address").ToString()
		End IF

		dtAdapter = Nothing
		objConn.Close()
		objConn = Nothing

End Sub

private void txtCode_TextChanged(object sender, EventArgs e)
{
	SqlConnection objConn = new SqlConnection();
	SqlDataAdapter dtAdapter = default(SqlDataAdapter);
	DataTable dt = new DataTable();


	string strConnString = null;
	strConnString = "Server=localhost;UID=sa;PASSWORD=;database=mydatabase;Max Pool Size=400;Connect Timeout=600;";
	objConn = new SqlConnection(strConnString);
	objConn.Open();

	string strSQL = null;
	strSQL = "SELECT * FROM supplier WHERE Code = '" + this.txtCode.Text + "' ";

	dtAdapter = new SqlDataAdapter(strSQL, objConn);
	dtAdapter.Fill(dt);

	if (dt.Row.Count > 0) {
		this.txtName.Text = dt.Rows[0]["Name"];
		this.txtAddress.Text = dt.Rows[0]["Address"];
	}

	dtAdapter = null;
	objConn.Close();
	objConn = null;

}