AutoValidate Enumeration
Determines how a control validates its data when it loses user input focus.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
| Member name | Description | |
|---|---|---|
![]() | Disable | Implicit validation will not occur. Setting this value will not interfere with explicit calls to Validate or ValidateChildren. |
![]() | EnablePreventFocusChange | Implicit validation occurs when the control loses focus. |
![]() | EnableAllowFocusChange | Implicit validation occurs, but if validation fails, focus will still change to the new control. If validation fails, the Validated event will not fire. |
![]() | Inherit | The control inherits its AutoValidate behavior from its container (such as a form or another control). If there is no container control, it defaults to EnablePreventFocusChange. |
If a user switches focus off of a Windows Forms control, the control will use AutoValidate to determine how to validate its data. This type of validation is called implicit validation, because it occurs without the application developer having to make an explicit call to Validate or ValidateChildren.
The property corresponding to this value will have different defaults based on the type of control. For more information, see User Input Validation in Windows Forms.
The following code example turns off implicit validation for a form and all of its contained controls, and instead manually performs validation of all of the form's children when a mouse button is clicked.
Imports System Imports System.Drawing Imports System.Windows.Forms Public Class Form1 Inherits Form 'Entry point which delegates to C-style main Private Function Public Overloads Shared Sub Main() Main(System.Environment.GetCommandLineArgs()) End Sub Private Overloads Shared Sub Main(ByVal args() As String) Application.EnableVisualStyles() Application.Run(New Form1()) End Sub 'Main Private WithEvents FirstNameBox, LastNameBox As TextBox Private WithEvents ValidateButton As Button Private FlowLayout1 As FlowLayoutPanel Private Sub New() End Sub Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load ' Turn off validation when a control loses focus. This will be inherited by child ' controls on the form, enabling us to validate the entire form when the ' button is clicked instead of one control at a time. Me.AutoValidate = System.Windows.Forms.AutoValidate.Disable FlowLayout1 = New FlowLayoutPanel() FlowLayout1.Dock = DockStyle.Fill FirstNameBox = New TextBox() FirstNameBox.Name = "FirstNameBox" FirstNameBox.Location = New Point(10, 10) FirstNameBox.Size = New Size(75, FirstNameBox.Size.Height) FirstNameBox.CausesValidation = True FlowLayout1.Controls.Add(FirstNameBox) LastNameBox = New TextBox() LastNameBox.Name = "LastNameBox" LastNameBox.Location = New Point(90, 10) LastNameBox.Size = New Size(75, LastNameBox.Size.Height) LastNameBox.CausesValidation = True FlowLayout1.Controls.Add(LastNameBox) ValidateButton = New Button() ValidateButton.Text = "Validate" ValidateButton.Location = New Point(170, 10) ValidateButton.Size = New Size(75, ValidateButton.Size.Height) FlowLayout1.Controls.Add(ValidateButton) Me.Text = "Test Validation" Me.Controls.Add(FlowLayout1) End Sub Private Sub FirstNameBox_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles FirstNameBox.Validating If FirstNameBox.Text.Length = 0 Then e.Cancel = True Else e.Cancel = False End If End Sub Private Sub LastNameBox_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles LastNameBox.Validating e.Cancel = False End Sub Private Sub ValidateButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles ValidateButton.Click If ValidateChildren() Then MessageBox.Show("Validation succeeded!") Else MessageBox.Show("Validation failed.") End If End Sub End Class
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
