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ValidationConstraints Enum

Definition

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.

C#
[System.Flags]
public enum ValidationConstraints
Inheritance
ValidationConstraints
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 true.

Visible 4

Validates child controls whose Visible property is set to true.

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.

C#
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);
        }
    }
}

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.

Applies to

Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also