ValidationConstraints Enum
Definition
Important
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Defines constants that inform ValidateChildren(ValidationConstraints) about how it should validate a container's child controls.
This enumeration supports a bitwise combination of its member values.
public enum class ValidationConstraints[System.Flags]
public enum ValidationConstraints[<System.Flags>]
type ValidationConstraints = Public Enum ValidationConstraints- Inheritance
- Attributes
Fields
| Name | Value | Description |
|---|---|---|
| None | 0 | Validates all child controls, and all children of these child controls, regardless of their property settings. |
| Selectable | 1 | Validates child controls that can be selected. |
| Enabled | 2 | Validates child controls whose Enabled property is set to |
| Visible | 4 | Validates child controls whose Visible property is set to |
| TabStop | 8 | Validates child controls that have a TabStop value set, which means that the user can navigate to the control using the TAB key. |
| ImmediateChildren | 16 | Validates 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. |
Examples
The following code example will only cause the Validating event to be raised for immediate children of the form whose Enabled property is true.
using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
namespace ValidateChildrenWithConstraints
{
class Form1 : Form
{
public static void Main(string[] args)
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
private Form1()
{
this.Load += new EventHandler(Form1_Load);
}
void Form1_Load(object sender, EventArgs e)
{
// Create controls on form.
TextBox textBox1, textBox2, textBox3;
FlowLayoutPanel flowPanel1;
TextBox subTextBox1;
Button button1;
this.Size = new Size(500, 300);
this.AutoValidate = AutoValidate.Disable;
textBox1 = new TextBox();
textBox1.Location = new Point(20, 20);
textBox1.Size = new Size(75, textBox1.Size.Height);
textBox1.CausesValidation = true;
textBox1.Validating += new System.ComponentModel.CancelEventHandler(textBox1_Validating);
this.Controls.Add(textBox1);
textBox2 = new TextBox();
textBox2.Location = new Point(105, 20);
textBox2.Size = new Size(75, textBox2.Size.Height);
textBox2.CausesValidation = true;
textBox2.Validating += new System.ComponentModel.CancelEventHandler(textBox2_Validating);
this.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;
textBox3.Validating += new System.ComponentModel.CancelEventHandler(textBox3_Validating);
this.Controls.Add(textBox3);
button1 = new Button();
button1.Text = "Click";
button1.Location = new Point(270, 20);
button1.Click += new EventHandler(button1_Click);
this.Controls.Add(button1);
flowPanel1 = new FlowLayoutPanel();
flowPanel1.Size = new Size(400, 100);
flowPanel1.Dock = DockStyle.Bottom;
subTextBox1 = new TextBox();
subTextBox1.CausesValidation = true;
subTextBox1.Validating += new System.ComponentModel.CancelEventHandler(subTextBox1_Validating);
flowPanel1.Controls.Add(subTextBox1);
this.Controls.Add(flowPanel1);
}
void subTextBox1_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
MessageBox.Show("subTextBox1 Validating!");
}
void textBox1_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
MessageBox.Show("textBox1 Validating!");
}
void textBox2_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
MessageBox.Show("textBox2 Validating!");
}
void textBox3_Validating(object sender, System.ComponentModel.CancelEventArgs e)
{
MessageBox.Show("textBox3 Validating!");
}
void button1_Click(object sender, EventArgs e)
{
this.ValidateChildren(ValidationConstraints.ImmediateChildren | ValidationConstraints.Enabled);
}
}
}
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
Sub SubTextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles SubTextBox1.Validating
MessageBox.Show("SubTextBox1 Validating!")
End Sub
Sub TextBox1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox1.Validating
MessageBox.Show("TextBox1 Validating!")
End Sub
Sub TextBox2_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox2.Validating
MessageBox.Show("TextBox2 Validating!")
End Sub
Sub TextBox3_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TextBox3.Validating
MessageBox.Show("TextBox3 Validating!")
End Sub
Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
Me.ValidateChildren((ValidationConstraints.ImmediateChildren Or ValidationConstraints.Enabled))
End Sub
End Class
End Namespace 'ValidateChildrenWithConstraints
Remarks
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. Combining parameters with a bitwise OR operator will result in a logical AND operation. For example, calling ValidateChildren(ValidationConstraints.ImmediateChildren | ValidationConstraints.Enabled) will only raise the Validating event on controls that are both immediate children of the container AND are enabled.
If you do not specify ImmediateChildren when you call ValidateChildren, the method will require that you validate all child controls in the control hierarchy.
