UpDownBase.ReadOnly Property

 

Gets or sets a value indicating whether the text can be changed by the use of the up or down buttons only.

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

Public Property ReadOnly As Boolean

Property Value

Type: System.Boolean

true if the text can be changed by the use of the up or down buttons only; otherwise, false. The default value is false.

By setting the ReadOnly property to true, you will eliminate the need for much validation of the Text property. The user will be restricted to the use of the up and down buttons to change the Text values. It will only allow them to select values you specify.

System_CAPS_noteNote

In the derived class DomainUpDown, the behavior described is slightly different. When ReadOnly is set to true and a key is pressed, the control selects the first item in the collection where the first character matches the key pressed.

The following code example uses the derived class NumericUpDown and sets some of its properties derived from UpDownBase. This code requires that you have a NumericUpDown control, two ComboBox controls, and three CheckBox controls created on a form. Label the ComboBox controls BorderStyle and TextAlign. Label the CheckBox controls InterceptArrowKeys, ReadOnly, and UpDownAlign. The code allows you to change the property values at run time and see how each affects the appearance and behavior of the spin box. Add the following items to the combo box labeled BorderStyle: None, Fixed3D, and FixedSingle. Add the following items to the combo box labeled TextAlign: Left, Right, and Center.

Private Sub comboBox1_SelectedIndexChanged(sender As Object, e As EventArgs)
    ' Set the BorderStyle property.
    Select Case comboBox1.Text
        Case "Fixed3D"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Case "None"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.None
        Case "FixedSingle"
            numericUpDown1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
    End Select
End Sub    

Private Sub comboBox2_SelectedIndexChanged(sender As Object, e As EventArgs)
    ' Set the TextAlign property.    
    Select Case comboBox2.Text
        Case "Right"
            numericUpDown1.TextAlign = HorizontalAlignment.Right
        Case "Left"
            numericUpDown1.TextAlign = HorizontalAlignment.Left
        Case "Center"
            numericUpDown1.TextAlign = HorizontalAlignment.Center
    End Select
End Sub    

Private Sub checkBox1_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the ReadOnly property.
    If numericUpDown1.ReadOnly Then
        numericUpDown1.ReadOnly = False
    Else
        numericUpDown1.ReadOnly = True
    End If
End Sub    

Private Sub checkBox2_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the InterceptArrowKeys property.
    If numericUpDown1.InterceptArrowKeys Then
        numericUpDown1.InterceptArrowKeys = False
    Else
        numericUpDown1.InterceptArrowKeys = True
    End If
End Sub    

Private Sub checkBox3_Click(sender As Object, e As EventArgs)
    ' Evaluate and toggle the UpDownAlign property.
    If numericUpDown1.UpDownAlign = LeftRightAlignment.Left Then
        numericUpDown1.UpDownAlign = LeftRightAlignment.Right
    Else
        numericUpDown1.UpDownAlign = LeftRightAlignment.Left
    End If
End Sub

.NET Framework
Available since 1.1
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