ValidationConstraints Enumeration

Note: This enumeration is new in the .NET Framework version 2.0.

Defines constants that inform ValidateChildren about how it should validate a container's child controls.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

'Declaration
<FlagsAttribute> _
Public Enumeration ValidationConstraints
'Usage
Dim instance As ValidationConstraints

/** @attribute FlagsAttribute() */ 
public enum ValidationConstraints
FlagsAttribute 
public enum ValidationConstraints

 Member nameDescription
EnabledValidates child controls whose Enabled property is set to true
ImmediateChildrenValidates child controls that are directly hosted within the container. Does not validate any of the children of these children. For example, if you have a Form that contains a custom UserControl, and the UserControl contains a Button, using ImmediateChildren will cause the Validating event of the UserControl to occur, but not the Validating event of the Button.  
NoneValidates all child controls, and all children of these child controls, regardless of their property settings.  
SelectableValidates child controls that can be selected. 
TabStopValidates child controls that have a TabStop value set, which means that the user can navigate to the control using the TAB key.  
VisibleValidates child controls whose Visible property is set to true

By default, ValidateChildren will validate all enabled controls in a container, such as a form. Use this enumeration to restrict the types of controls whose Validating event is raised.

You can combine these enumerated values together with a bitwise OR operation. With this you can instruct a call to ValidateChildren to validate, such as only enabled controls that are immediate children of the container.

If you do not specify ImmediateChildren when you call ValidateChildren, the method will require that you validate all child controls in the control hierarchy.

The following code example will only cause the Validating event to be raised for immediate children of the form whose Enabled property is true.

Imports System.Drawing
Imports System.Windows.Forms

Namespace ValidateChildrenWithConstraints
    _
    Class Form1
        Inherits Form

        Public Overloads Shared Sub Main(ByVal args() As String)
            Application.EnableVisualStyles()
            Application.Run(New Form1())
        End Sub

        Private Sub New()
            AddHandler Me.Load, AddressOf Form1_Load
        End Sub

        Dim WithEvents TextBox1, TextBox2, TextBox3 As TextBox
        Dim FlowPanel1 As FlowLayoutPanel
        Dim WithEvents SubTextBox1 As TextBox
        Dim WithEvents Button1 As Button

        Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
            ' Create controls on form.

            Me.Size = New Size(500, 300)
            Me.AutoValidate = AutoValidate.Disable

            TextBox1 = New TextBox()
            TextBox1.Location = New Point(20, 20)
            TextBox1.Size = New Size(75, TextBox1.Size.Height)
            TextBox1.CausesValidation = True
            Me.Controls.Add(TextBox1)

            TextBox2 = New TextBox()
            TextBox2.Location = New Point(105, 20)
            TextBox2.Size = New Size(75, TextBox2.Size.Height)
            TextBox2.CausesValidation = True
            Me.Controls.Add(TextBox2)

            TextBox3 = New TextBox()
            TextBox3.Location = New Point(190, 20)
            TextBox3.Size = New Size(75, TextBox3.Size.Height)
            TextBox3.Enabled = False
            TextBox3.CausesValidation = True
            Me.Controls.Add(TextBox3)

            Button1 = New Button()
            Button1.Text = "Click"
            Button1.Location = New Point(270, 20)
            Me.Controls.Add(Button1)

            FlowPanel1 = New FlowLayoutPanel()
            FlowPanel1.Size = New Size(400, 100)
            FlowPanel1.Dock = DockStyle.Bottom
            SubTextBox1 = New TextBox()
            SubTextBox1.CausesValidation = True
            FlowPanel1.Controls.Add(SubTextBox1)
            Me.Controls.Add(FlowPanel1)
        End Sub 'Form1_Load


        Sub SubTextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles SubTextBox1.Validating
            MessageBox.Show("SubTextBox1 Validating!")
        End Sub 'SubTextBox1_Validating


        Sub TextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox1.Validating
            MessageBox.Show("TextBox1 Validating!")
        End Sub 'TextBox1_Validating


        Sub TextBox2_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox2.Validating
            MessageBox.Show("TextBox2 Validating!")
        End Sub 'TextBox2_Validating


        Sub TextBox3_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox3.Validating
            MessageBox.Show("TextBox3 Validating!")
        End Sub 'TextBox3_Validating


        Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
            Me.ValidateChildren((ValidationConstraints.ImmediateChildren Or ValidationConstraints.Enabled))
        End Sub 'Button1_Click
    End Class 'Form1
End Namespace 'ValidateChildrenWithConstraints

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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