samples/snippets/visualbasic/VS_Snippets_VBCSharp/VbVersHelp60Controls/VB/Form3.vb - main - aprogrammer/dotnet-docs

samples/snippets/visualbasic/VS_Snippets_VBCSharp/VbVersHelp60Controls/VB/Form3.vb
172 строки5 KB
Andy De George
Move snippets from samples repo to this repo (#17296)
03 мар 2020, 19:23
03 мар 2020, 19:23dbbeda1
Public Class Form3


'*************************************************************************
'<Snippet72>
' Visual Basic
Private Sub Form1_Load2() Handles MyBase.Load
        Me.TextBox1.MaxLength = 5
    End Sub
    Private Sub SetText()
        ' Truncate the string to equal MaxLength.
        Me.TextBox1.Text = Strings.Left("Hello World", Me.TextBox1.MaxLength)
    End Sub
    '</Snippet72>


    '*************************************************************************
    '<Snippet71>
    ' Visual Basic
    Private Sub Form1_Load() Handles MyBase.Load
        Me.TextBox1.Text = "Two of the peak human experiences are "
        Me.TextBox1.Text = Me.TextBox1.Text & "good food and classical music."
    End Sub
    Private Sub Form1_Click() Handles Me.Click
        Dim Search As String
        Dim Where As String
        ' Get search string from user.
        Search = InputBox("Enter text to be found:")
        ' Find string in text.
        Where = InStr(Me.TextBox1.Text, Search)
        If Where Then
            Me.TextBox1.Focus()
            Me.TextBox1.SelectionStart = Where - 1
            Me.TextBox1.SelectionLength = Len(Search)
        Else
            MsgBox("String not found.")
        End If
    End Sub
    '</Snippet71>


    '*************************************************************************
    Private Sub Form3_Load(sender As Object, e As System.EventArgs) Handles MyBase.Load
        '<Snippet60>
        ' Assign the first image (Picture) to the Image property.
        Me.CheckBox1.Image = Me.ImageList1.Images(0)
        '</Snippet60>
    End Sub


    '*************************************************************************
    Private Sub Test2()
        '<Snippet62>
        If Me.CheckBox1.Enabled = False Then
            ' Assign the third image (DisabledPicture) to the Image property.
            Me.CheckBox1.Image = Me.ImageList1.Images(2)
        ElseIf Me.CheckBox1.Checked = True Then
            ' Assign the second image (DownPicture) to the Image property
            Me.CheckBox1.Image = Me.ImageList1.Images(1)
        Else
            ' Assign the first image (Picture)to the Image property
            Me.CheckBox1.Image = Me.ImageList1.Images(0)
        End If
        '</Snippet62>
    End Sub


    '*************************************************************************
    Private Sub Test()
        '<Snippet61>
        If Me.CheckBox1.Checked = True Then
            ' Assign the second image (DownPicture) to the Image property.
            Me.CheckBox1.Image = Me.ImageList1.Images(1)
        Else
            ' Assign the first image (Picture) to the Image property.
            Me.CheckBox1.Image = Me.ImageList1.Images(0)
        End If
        '</Snippet61>


        '<Snippet79>
        ' Visual Basic
        ' Specify the color to be used as a mask and use the mask.
        Me.ImageList1.TransparentColor = Color.White
        ' Don't use the mask.
        Me.ImageList1.TransparentColor = Color.Transparent
        '</Snippet79>


    End Sub



    '******************************************************************************
    '<Snippet17>
    ' Visual Basic
    Private Sub Button1_Click(sender As Object, e As System.EventArgs) Handles Button1.Click
        ' Create a new TextBox control.
        Dim TextBox1 As New System.Windows.Forms.TextBox With {
            .Name = "TextBox1"
        }
        ' Add the new control to the form's Controls collection.
        Me.Controls.Add(TextBox1)
        ' No need to set Visible property.
        ' Set the initial text.
        TextBox1.Text = "Hello"
        ' Retrieve the text from the new TextBox.
        If Me.Controls.Count > 1 Then
            MsgBox(Me.Controls("TextBox1").Text)
        End If
        ' Remove the new control.
        Me.Controls.Remove(TextBox1)
        ' Remove the control added at design time.
        Me.Controls.Remove(Me.Button1)
    End Sub
    '</Snippet17>


    '******************************************************************************
    '<Snippet18>
    ' Visual Basic
    Private Sub ClearChecks(Container As Control)
        Dim ctl As Control
        Dim chk As CheckBox
        For Each ctl In Container.Controls
            If TypeOf ctl Is CheckBox Then
                chk = ctl
                chk.Checked = False
            End If
            ' Recursively call this function for any container controls.
            If ctl.HasChildren Then
                Me.ClearChecks(ctl)
            End If
        Next
    End Sub
    '</Snippet18>


    Private Sub Button2_Click(sender As Object, e As System.EventArgs) Handles Button2.Click
        Me.ClearChecks(Me.GroupBox1)
    End Sub


    '******************************************************************************
    '<Snippet20>
    ' Visual Basic
    Private Sub TextBox1_Validating(
    sender As Object,
    e As System.ComponentModel.CancelEventArgs
  ) Handles TextBox1.Validating

        If Me.TextBox1.Text = "" Then
            MsgBox("Please enter a name")
            e.Cancel = True
        End If
    End Sub
    '</Snippet20>


    '******************************************************************************
    '<Snippet21>
    Private Sub Form1_FormClosing(
    sender As Object,
    e As System.Windows.Forms.FormClosingEventArgs
  ) Handles MyBase.FormClosing
        ' If validation failed cancel the Closing event.
        If Me.Validate = False Then
            e.Cancel = True
        End If
    End Sub
    '</Snippet21>
End Class