Programming Microsoft Visual Basic .NET/Programming Microsoft Visual Basic .NET (Microsoft Press)(X08-78517)(2002).bin/setup/vbnet/16 windows forms/windowsformsdemo/dyncontrolform.vb

Text File | 2002-03-16 | 5.4 KB | 140 lines

Public Class DynControlForm
    Inherits System.Windows.Forms.Form

#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

    'Form 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
    Friend WithEvents lblStatus As System.Windows.Forms.Label
    Friend WithEvents chkUpperCase As System.Windows.Forms.CheckBox
    Friend WithEvents btnCreateControls As System.Windows.Forms.Button

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

    '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()
        Me.btnCreateControls = New System.Windows.Forms.Button()
        Me.chkUpperCase = New System.Windows.Forms.CheckBox()
        Me.lblStatus = New System.Windows.Forms.Label()
        Me.SuspendLayout()
        '
        'btnCreateControls
        '
        Me.btnCreateControls.Location = New System.Drawing.Point(16, 24)
        Me.btnCreateControls.Name = "btnCreateControls"
        Me.btnCreateControls.Size = New System.Drawing.Size(136, 32)
        Me.btnCreateControls.TabIndex = 0
        Me.btnCreateControls.Text = "Create Controls"
        '
        'chkUpperCase
        '
        Me.chkUpperCase.Location = New System.Drawing.Point(168, 64)
        Me.chkUpperCase.Name = "chkUpperCase"
        Me.chkUpperCase.Size = New System.Drawing.Size(240, 16)
        Me.chkUpperCase.TabIndex = 2
        Me.chkUpperCase.Text = "Convert keys to upper case"
        '
        'lblStatus
        '
        Me.lblStatus.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.lblStatus.Location = New System.Drawing.Point(168, 24)
        Me.lblStatus.Name = "lblStatus"
        Me.lblStatus.Size = New System.Drawing.Size(336, 24)
        Me.lblStatus.TabIndex = 1
        '
        'DynControlForm
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(568, 269)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.chkUpperCase, Me.lblStatus, Me.btnCreateControls})
        Me.Name = "DynControlForm"
        Me.Text = "DynControlForm"
        Me.ResumeLayout(False)

    End Sub

#End Region

    ' create any number of controls dynamically

    Private Sub btnCreateControls_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCreateControls.Click
        Dim answer As String
        Dim index As Integer

        answer = InputBox("How many controls?", "Dynamic Control Creation", "5")
        If answer = "" Then Exit Sub

        For index = 1 To CInt(answer)
            ' Create the textbox
            Dim tb As New TextBox()
            tb.Size = New System.Drawing.Size(400, 30)
            tb.Location = New System.Drawing.Point(50, 40 + index * 40)
            'tb.Visible = True
            ' we need this to identify the control
            tb.Name = "TextBox #" & CStr(index)
            ' add to the controls collection
            Me.Controls.Add(tb)

            ' prepare event handlers
            AddHandler tb.KeyPress, AddressOf TextBox_KeyPress
            AddHandler tb.TextChanged, AddressOf TextBox_TextChanged
            AddHandler tb.MouseEnter, AddressOf TextBox_MouseEnter
            AddHandler tb.MouseLeave, AddressOf TextBox_MouseLeave
        Next
    End Sub

    ' a generic control handler that caps the pressed key

    Private Sub TextBox_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs)
        ' exit if no conversion to upper case is required
        If Not chkUpperCase.Checked Then Exit Sub
        ' exit if char doesn't have to be converted
        If Not Char.IsLower(e.KeyChar) Then Exit Sub

        ' insert the key there
        DirectCast(sender, TextBox).SelectedText = Char.ToUpper(e.KeyChar)
        ' signal that this key has been dealt with
        e.Handled = True
    End Sub

    ' generic MouseEnter handler that changes the background color

    Private Sub TextBox_MouseEnter(ByVal sender As System.Object, ByVal e As System.EventArgs)
        lblStatus.Text = "MouseEnter in " & CStr(CType(sender, TextBox).Name)
        DirectCast(sender, TextBox).BackColor = Color.Yellow
    End Sub

    ' generic MouseLeave handler that restores the background color

    Private Sub TextBox_MouseLeave(ByVal sender As System.Object, ByVal e As System.EventArgs)
        lblStatus.Text = "MouseLeave in " & CStr(CType(sender, TextBox).Name)
        DirectCast(sender, TextBox).BackColor = SystemColors.Window
    End Sub

    ' generic TextChanged event handler

    Private Sub TextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
        lblStatus.Text = "TextChanged in " & CStr(CType(sender, TextBox).Name)
    End Sub
End Class