ผมจะเอาค่าที่ผม รวม มาโชว์ ยังงัย ครับ โชว์ที่ Label

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Dim dtAdapter As System.Data.SqlClient.SqlDataAdapter
        Dim dt As New DataTable
        Dim objConn As New SqlConnection
        Dim ds As New DataSet
        Dim objCmd As New SqlCommand
        Dim strConnString, strSQL As String
        strConnString = "Server=IT-04S\SQLEXPRESS;UID=TestVB;PASSWORD=11111;database=TestVB;Max Pool Size=400;Connect Timeout=600;"
        objConn = New System.Data.SqlClient.SqlConnection(strConnString)
        objConn.Open()
        Dim intNumRows As Integer
        strSQL = "SELECT sum(" & Me.ListBox1.Text & ") FROM DATASale WHERE พนง#ขาย = '" & Me.ComboBox1.Text & "'"
        objCmd = New SqlCommand(strSQL, objConn)
        intNumRows = objCmd.ExecuteScalar()
        'Label1.Text = strSQL

    End Sub