UpDownBase.Select Method (Int32, Int32)


Selects a range of text in the spin box (also known as an up-down control) specifying the starting position and number of characters to select.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

Public Sub Select (
	start As Integer,
	length As Integer


Type: System.Int32

The position of the first character to be selected.

Type: System.Int32

The total number of characters to be selected.

The Select method can be used when the spin box gets focus, or when the Text property fails data validation. When adding the validation code for the ValidateEditText method in a derived class, call the Select method when validation fails.

The following code example uses the derived class NumericUpDown. This code requires that a NumericUpDown control and a Button have been created on a form and the System.Drawing namespace has been added as a reference. On the Click event for the button, the point size of text in the NumericUpDown control increases. This prompts the control to adjust its PreferredHeight property so that all the text is visible in the control. After the user enters a new value and leaves the NumericUpDown control, the text is converted to a numeric value from a string value and validated to be between the Minimum and Maximum values. If the value is not valid, a MessageBox is displayed with the error, and the Select method will select the text so the user can enter a new value.

Private Sub numericUpDown1_Leave(sender As Object, e As EventArgs)
    ' If the entered value is greater than Minimum or Maximum,
    ' select the text and open a message box. 
    If (System.Convert.ToInt32(numericUpDown1.Text) > numericUpDown1.Maximum) Or _
        (System.Convert.ToInt32(numericUpDown1.Text) < numericUpDown1.Minimum) Then
        MessageBox.Show("The value entered was not between the Minimum and " & _
            "Maximum allowable values." & Microsoft.VisualBasic.ControlChars.Cr & _
            "Please re-enter.")
        numericUpDown1.Select(0, numericUpDown1.Text.Length)
    End If
End Sub    

Private Sub button1_Click(sender As Object, e As EventArgs)
    Dim varPrefHeight1 As Integer

    ' Capture the PreferredHeight before and after the Font
    ' is changed, and display the results in a message box. 
    varPrefHeight1 = numericUpDown1.PreferredHeight
    numericUpDown1.Font = New System.Drawing.Font("Microsoft Sans Serif", _
        12F, System.Drawing.FontStyle.Bold)
    MessageBox.Show("Before Font Change: " & varPrefHeight1.ToString() & _
        Microsoft.VisualBasic.ControlChars.Cr & "After Font Change: " & _
End Sub

.NET Framework
Available since 1.1
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