Show Hide TextBoxes based on ComboBox selection in Windows Forms (WinForms) Application using C# and VB.Net

Hi kinoh28,

I have made one sample that full-fill your requirement.

Code

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
    ClearAll()
End Sub

Private Sub cbType_SelectedValueChanged(sender As System.Object, e As System.EventArgs) Handles cbType.SelectedValueChanged
    Dim selectedText As String = cbType.SelectedItem.ToString()
    Select Case selectedText
        Case "A"
            lblTrunks.Visible = True
            lblCards.Visible = True
            txtTrunks.Visible = True
            txtCards.Visible = True
            Exit Select
        Case "B"
            lblTrunks.Visible = True
            lblCards.Visible = True
            lblCapacity.Visible = True
            txtTrunks.Visible = True
            txtCards.Visible = True
            txtCapacity.Visible = True
            Exit Select
        Case Else
             ClearAll()
             Exit Select
    End Select
End Sub

Private Sub ClearAll()
    lblTrunks.Visible = False
    lblCards.Visible = False
    lblCapacity.Visible = False
    txtTrunks.Visible = False
    txtCards.Visible = False
    txtCapacity.Visible = False
End Sub

Screenshot