ContainerControl.ValidateChildren Método

public:
 virtual bool ValidateChildren();

[System.ComponentModel.Browsable(false)]
public virtual bool ValidateChildren ();

[<System.ComponentModel.Browsable(false)>]
abstract member ValidateChildren : unit -> bool
override this.ValidateChildren : unit -> bool

Public Overridable Function ValidateChildren () As Boolean

Retornos

true se todos os filhos forem validados com êxito; caso contrário, false. Se for chamado dos manipuladores de eventos Validating ou Validated , esse método sempre retornará false.

Atributos

BrowsableAttribute

Exemplos

O exemplo de código a seguir desativa a validação implícita para um formulário e todos os seus controles contidos e, em vez disso, executa manualmente a validação de todos os filhos do formulário quando um botão do mouse é clicado.

using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Drawing;
using System.Text;

namespace TestValidation
{
    class Form1 : Form
    {
        private static void Main(string[] args)
        {
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }

        private TextBox firstNameBox, lastNameBox;
        private Button validateButton;
        private FlowLayoutPanel flowLayout1;

        private Form1()
        {
            this.Load += new EventHandler(Form1_Load);
        }

        void Form1_Load(object sender, EventArgs e)
        {
            // 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.
            this.AutoValidate = AutoValidate.Disable;

            flowLayout1 = new FlowLayoutPanel();
            flowLayout1.Dock = DockStyle.Fill;
            flowLayout1.Name = "flowLayout1";

            firstNameBox = new TextBox();
            firstNameBox.Name = "firstNameBox";
            firstNameBox.Size = new Size(75, firstNameBox.Size.Height);
            firstNameBox.CausesValidation = true;
            firstNameBox.Validating += new System.ComponentModel.CancelEventHandler(firstNameBox_Validating);
            flowLayout1.Controls.Add(firstNameBox);

            lastNameBox = new TextBox();
            lastNameBox.Name = "lastNameBox";
            lastNameBox.Size = new Size(75, lastNameBox.Size.Height);
            lastNameBox.CausesValidation = true;
            lastNameBox.Validating += new System.ComponentModel.CancelEventHandler(lastNameBox_Validating);
            flowLayout1.Controls.Add(lastNameBox);

            validateButton = new Button();
            validateButton.Text = "Validate";
            // validateButton.Location = new Point(170, 10);
            validateButton.Size = new Size(75, validateButton.Size.Height);
            validateButton.Click += new EventHandler(validateButton_Click);
            flowLayout1.Controls.Add(validateButton);

            this.Controls.Add(flowLayout1);

            this.Text = "Test Validation";
        }

        void firstNameBox_Validating(object sender, System.ComponentModel.CancelEventArgs e)
        {
            if (firstNameBox.Text.Length == 0)
            {
                e.Cancel = true;
            }
            else
            {
                e.Cancel = false;
            }
        }

        void lastNameBox_Validating(object sender, System.ComponentModel.CancelEventArgs e)
        {
            e.Cancel = false;
        }

        void validateButton_Click(object sender, EventArgs e)
        {
            if (this.ValidateChildren())
            {
                MessageBox.Show("Validation succeeded!");
            }
            else
            {
                MessageBox.Show("Validation failed.");
            }
        }
    }
}

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

    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

Comentários

ValidateChildren descerá a hierarquia de um controle e examinará cada controle para ver se ele dá suporte à validação. Se o controle puder ser selecionado pelo usuário e sua CausesValidation propriedade for true, ValidateChildren fará com que o Validating evento ocorra. Se qualquer um dos controles cancelar o Validating evento, esse método retornará false; caso contrário, retornará true.

Se um controle estiver associado a uma fonte de dados e o Validating evento ocorrer, ele fará com que o controle envie seus dados atuais de volta para a fonte de dados.

Chamar ValidateChildren é equivalente a chamar ValidateChildren com um ValidationConstraints de None.

public:
 virtual bool ValidateChildren(System::Windows::Forms::ValidationConstraints validationConstraints);

[System.ComponentModel.Browsable(false)]
public virtual bool ValidateChildren (System.Windows.Forms.ValidationConstraints validationConstraints);

[<System.ComponentModel.Browsable(false)>]
abstract member ValidateChildren : System.Windows.Forms.ValidationConstraints -> bool
override this.ValidateChildren : System.Windows.Forms.ValidationConstraints -> bool

Public Overridable Function ValidateChildren (validationConstraints As ValidationConstraints) As Boolean

Parâmetros

Retornos

true se todos os filhos forem validados com êxito; caso contrário, false. Se for chamado dos manipuladores de eventos Validating ou Validated , esse método sempre retornará false.

Atributos

BrowsableAttribute

Exemplos

O exemplo de código a seguir fará com que o Validating evento ocorra apenas para filhos imediatos do formulário cuja Enabled propriedade é 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

Comentários

ValidateChildren examinará todos os filhos do controle atual, fazendo com que o Validating evento ocorra em um controle se atender aos critérios escritos por ValidationConstraints.

Você pode usar vários ValidationConstraints parâmetros ao mesmo tempo combinando-os com um operador OR bit a bit. Combinar parâmetros com um operador OR bit a bit resultará em uma operação AND lógica. Por exemplo, chamar ValidateChildren(ValidationConstraints.ImmediateChildren | ValidationConstraints.Enabled) só gerará o Validating evento em controles que são filhos imediatos do contêiner E estão habilitados.

Independentemente de quais parâmetros você especificar para esse método, um controle deve ter sua CausesValidation propriedade definida true como para que o Validating evento ocorra. Você também deve definir a AutoValidate propriedade do controle ou do contêiner do controle como false se desejar que a validação ocorra somente quando você chamar ValidateChildrene não quando o usuário mudar o foco do controle.

Se um controle estiver associado a uma fonte de dados e o Validating evento ocorrer, ele fará com que o controle envie seus dados atuais de volta para a fonte de dados.

Você não pode obter o efeito oposto de um ValidationConstraints parâmetro aplicando um operador de negação bit a bit. Por exemplo, se você fornecer o valor negativo do Visible campo para ValidateChildren, ele não validará todos os filhos que não estão visíveis no contêiner. Fornecer qualquer parâmetro negativo para ValidateChildren não terá nenhum efeito sobre o contêiner ou seus filhos.