Programming Excel with VBA and .NET

Enable and Disable Controls

It is common practice to enable or disable controls based on what other options are selected. Controls are enabled by default. Use the control’s Enabled property to disable or reenable the control after disabling.

For example, to make the View Chart button available only after the user has clicked Get History, set the View Chart button’s Enabled property to False in the Properties window, and add this code to the cmdGetHistory_Click procedure:

    Private Sub cmdGetHistory_Click(  )
        Dim fname As String
        ' Show the source worksheet.
        Worksheets("VBForm").Activate
        ' Make sure the user entered a symbol.
        If txtSymbol.Text <> "" Then
            ResetWorksheet
            CreateQuery txtSymbol.Text, spnDays.Value
            HideUnneededCells
            fname = CreateChart(imgChart.height, imgChart.width)
            ' Update the image control.
            Set imgChart.Picture = LoadPicture(fname)
        End If
        ' Add this to enable View Chart button.
        cmdViewChart.Enabled = True
    End Sub

While disabled, the control appears grayed and cannot receive user actions. You can do something similar by setting the control’s Visible property, but that is less common. Hiding and showing controls is usually reserved for complex or multistep tasks.