Hai All,

is there anybody here who have experience with developing custom controls? especially the textbox control.

The easy way is to inherit the .NET's TextBox control.

If there's any circumstance that not allowed us to inherit from that control, how we can do it?

Inherit from UserControl? or Control?

What we use to trap keyboard event? Is it suficient if we use KeyUp/KeyDown/KeyPressed?

What we use to display blinking cursor? using timer?

Thanks and regards,

Lok

hi,

i think the follwing code will help

Ashu

'******************************************

Public Class NumericTextBox
    Inherits System.Windows.Forms.TextBox

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'UserControl1 overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        '
        'NumericTextBox
        '
        Me.AccessibleRole = System.Windows.Forms.AccessibleRole.Application
        Me.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle

    End Sub

#End Region

    Private Sub NumericTextBox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress
        Dim KeyAscii As Integer

        KeyAscii = Asc(e.KeyChar)

        Select Case KeyAscii

            Case 48 To 57, 8, 13 '0-9, Backspace, Enter KEY
                'Do nothing

            Case 45 'Minus sign (-)
                If InStr(Me.Text, "-") <> 0 Then
                    KeyAscii = 0
                End If

                If Me.SelectionStart <> 0 Then
                    KeyAscii = 0
                End If

            Case 46 'Dot (.)
                If InStr(Me.Text, ".") Then
                    KeyAscii = 0
                End If

            Case Else
                KeyAscii = 0

        End Select

        If KeyAscii = 0 Then
            e.Handled = True
        Else
            e.Handled = False
        End If
    End Sub

    Private Sub NumericTextBox_Enter(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Enter
        Me.SelectionStart = 0
        Me.SelectionLength = Me.Text.Length
    End Sub

End Class

Thanks Ashu,

Unfortunately, that's not what I'm looking for.

The one that I'm looking is a custom control that directly inherit System.Windows.Forms.Control or System.Windows.Forms.UserControl, not the one who inherits from other ready-made control (in your case it inherits System.Windows.Forms.TextBox control).

I need to know what happening behind the screen to produce TextBox-like control without inheriting it.

Thanks & regards,

Lok