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LayoutEventArgs Class
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LayoutEventArgs Class

Provides data for the Layout event. This class cannot be inherited.

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

'Declaration
Public NotInheritable Class LayoutEventArgs
	Inherits EventArgs
'Usage
Dim instance As LayoutEventArgs

public final class LayoutEventArgs extends EventArgs
public final class LayoutEventArgs extends EventArgs

Changes to a control such as resizing, showing or hiding child controls, and adding or removing child controls make it necessary for a control to layout its child controls. A LayoutEventArgs specifies the child control that has been changed and its affected property. For example, if a control has been made visible since the last layout operation, the Visible property is affected.

The AffectedControl and AffectedProperty properties are set to a null reference (Nothing in Visual Basic) if no values were provided when the PerformLayout method was called.

For more information about handling events, see Consuming Events.

The following code example uses the AffectedProperty and AffectedControl properties as LayoutEventHandler arguments to coordinate the size of a Windows form and its controls with various property changes to both the Windows form and the controls.

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private WithEvents textBox1 As System.Windows.Forms.TextBox
    Private label1 As System.Windows.Forms.Label
    Private layoutButton As System.Windows.Forms.Button
    Private components As System.ComponentModel.Container = Nothing


    Public Sub New()
        InitializeComponent()
    End Sub

    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    Private Sub InitializeComponent()
        Me.layoutButton = New System.Windows.Forms.Button()
        Me.textBox1 = New System.Windows.Forms.TextBox()
        Me.label1 = New System.Windows.Forms.Label()
        Me.SuspendLayout()
        ' 
        ' layoutButton
        ' 
        Me.layoutButton.Anchor = System.Windows.Forms.AnchorStyles.Bottom
        Me.layoutButton.Location = New System.Drawing.Point(72, 88)
        Me.layoutButton.Name = "layoutButton"
        Me.layoutButton.Size = New System.Drawing.Size(150, 23)
        Me.layoutButton.TabIndex = 0
        Me.layoutButton.Text = "Hello"
        ' 
        ' textBox1
        ' 
        Me.textBox1.Anchor = System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Left Or System.Windows.Forms.AnchorStyles.Right
        Me.textBox1.Location = New System.Drawing.Point(24, 40)
        Me.textBox1.Name = "textBox1"
        Me.textBox1.Size = New System.Drawing.Size(248, 20)
        Me.textBox1.TabIndex = 1
        Me.textBox1.Text = "Hello"
        ' 
        ' label1
        ' 
        Me.label1.Location = New System.Drawing.Point(24, 16)
        Me.label1.Name = "label1"
        Me.label1.TabIndex = 2
        Me.label1.Text = "Button's Text:"
        ' 
        ' Form1
        ' 
        Me.ClientSize = New System.Drawing.Size(292, 129)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.label1, Me.textBox1, Me.layoutButton})
        Me.Name = "Form1"
        Me.Text = "Layout Sample"
        Me.ResumeLayout(False)
    End Sub

   ' This method ensures that the form's width is the preferred size of 300 pixels
   ' or the size of the button plus 50 pixels, whichever amount is less.
    Private Sub Form1_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles MyBase.Layout
      ' This event is raised once at startup with the AffectedControl
      ' and AffectedProperty properties on the LayoutEventArgs as null. 
      ' The event provides size preferences for that case.
        If Not (e.AffectedControl Is Nothing) And Not (e.AffectedProperty Is Nothing) Then
            ' Ensure that the affected property is the Bounds property
            ' of the form.
            If e.AffectedProperty.ToString() = "Bounds" Then
             ' If layoutButton's width plus a padding of 50 pixels is greater than the preferred 
             ' size of 300 pixels, increase the form's width.
                If Me.layoutButton.Width + 50 > 300 Then
                    Me.Width = Me.layoutButton.Width + 50
                    ' If not, keep the form's width at 300 pixels.
                Else
                    Me.Width = 300
                End If

                ' Center layoutButton on the form.
                Me.layoutButton.Left = (Me.ClientSize.Width - Me.layoutButton.Width) / 2
            End If
        End If
    End Sub

    ' This method sets the Text property of layoutButton to the Text property
    ' of textBox1.  If the new text plus a padding of 20 pixels is larger than 
    ' the preferred size of 150 pixels, increase layoutButton's Width property.
    Private Sub textBox1_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles textBox1.TextChanged
        ' Set the Text property of layoutButton.
        Me.layoutButton.Text = Me.textBox1.Text
        ' Get the width of the text using the proper font.
        Dim textWidth As Integer = CInt(Me.CreateGraphics().MeasureString(layoutButton.Text, layoutButton.Font).Width)

        ' If the width of the text plus a padding of 20 pixels is greater than the preferred size of
        ' 150 pixels, increase layoutButton's width.
        If textWidth + 20 > 150 Then
            ' Setting the size property on any control raises 
            ' the Layout event for its container.
            Me.layoutButton.Width = textWidth + 20
            ' If not, keep layoutButton's width at 150 pixels.
        Else
            Me.layoutButton.Width = 150
        End If
    End Sub
End Class

public class Form1 extends System.Windows.Forms.Form
{
    private System.Windows.Forms.TextBox textBox1;
    private System.Windows.Forms.Label label1;
    private System.Windows.Forms.Button layoutButton;
    private System.ComponentModel.Container components = null;

    public Form1()
    {
        InitializeComponent();
    } //Form1

    protected void Dispose(boolean disposing)
    {
        if (disposing) {
            if (components != null) {
                components.Dispose();
            }
        }
        super.Dispose(disposing);
    } //Dispose

    private void InitializeComponent()
    {
        this.layoutButton = new System.Windows.Forms.Button();
        this.textBox1 = new System.Windows.Forms.TextBox();
        this.label1 = new System.Windows.Forms.Label();
        this.SuspendLayout();
        //
        // layoutButton
        //
        this.layoutButton.set_Anchor(System.Windows.Forms.AnchorStyles.Bottom);
        this.layoutButton.set_Location(new System.Drawing.Point(72, 88));
        this.layoutButton.set_Name("layoutButton");
        this.layoutButton.set_Size(new System.Drawing.Size(150, 23));
        this.layoutButton.set_TabIndex(0);
        this.layoutButton.set_Text("Hello");
        //
        // textBox1
        //
        this.textBox1.set_Anchor(System.Windows.Forms.AnchorStyles.Top 
            | System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.
            AnchorStyles.Right);
        this.textBox1.set_Location(new System.Drawing.Point(24, 40));
        this.textBox1.set_Name("textBox1");
        this.textBox1.set_Size(new System.Drawing.Size(248, 20));
        this.textBox1.set_TabIndex(1);
        this.textBox1.set_Text("Hello");
        this.textBox1.add_TextChanged(new System.EventHandler(this.
            textBox1_TextChanged));
        //
        // label1
        //
        this.label1.set_Location(new System.Drawing.Point(24, 16));
        this.label1.set_Name("label1");
        this.label1.set_TabIndex(2);
        this.label1.set_Text("Button\'s Text:");
        //
        // Form1
        //
        this.set_ClientSize(new System.Drawing.Size(292, 129));
        this.get_Controls().AddRange(new System.Windows.Forms.Control[] { this.
            label1, this.textBox1, this.layoutButton });
        this.set_Name("Form1");
        this.set_Text("Layout Sample");
        this.add_Layout(new System.Windows.Forms.LayoutEventHandler(this.
            Form1_Layout));
        this.ResumeLayout(false);
    } //InitializeComponent

    /** @attribute STAThread()
     */
    public static void main(String[] args)
    {
        Application.Run(new Form1());
    } //main

   // This method ensures that the form's width is the preferred size of 300 pixels
   // or the size of the button plus 50 pixels, whichever amount is less.
    private void Form1_Layout(Object sender,
        System.Windows.Forms.LayoutEventArgs e)
    {
      // This event is raised once at startup with the AffectedControl
      // and AffectedProperty properties on the LayoutEventArgs as null. 
      // The event provides size preferences for that case.
        if (e.get_AffectedControl() != null 
            && e.get_AffectedProperty() != null) {
            // Ensure that the affected property is the Bounds property
            // of the form.
            if ((e.get_AffectedProperty().ToString()).Equals("Bounds")) {
            // If layoutButton's width plus a padding of 50 pixels is greater 
            // than the preferred size of 300 pixels, increase the form's width.
                if (this.layoutButton.get_Width() + 50 > 300) {
                    this.set_Width(this.layoutButton.get_Width() + 50);
                }
                    // If not, keep the form's width at 300 pixels.
                else {
                    this.set_Width(300);
                }

                // Center layoutButton on the form.
                this.layoutButton.set_Left((this.get_ClientSize().get_Width() 
                    - this.layoutButton.get_Width()) / 2);
            }
        }
    } //Form1_Layout

    // This method sets the Text property of layoutButton to the Text property
    // of textBox1.  If the new text plus a padding of 20 pixels is larger than 
    // the preferred size of 150 pixels, increase layoutButton's Width property.
    private void textBox1_TextChanged(Object sender, System.EventArgs e)
    {
        // Set the Text property of layoutButton.
        this.layoutButton.set_Text(this.textBox1.get_Text());
        // Get the width of the text using the proper font.
        int textWidth = (int)(this.CreateGraphics().MeasureString(layoutButton.
            get_Text(), layoutButton.get_Font()).get_Width());

        // If the width of the text plus a padding of 20 pixels is greater than the preferred size of
        // 150 pixels, increase layoutButton's width.
        if (textWidth + 20 > 150){
            // Setting the size property on any control raises 
            // the Layout event for its container.
            this.layoutButton.set_Width(textWidth + 20);
        }
            // If not, keep layoutButton's width at 150 pixels.
        else{
            this.layoutButton.set_Width(150);
        }
    } //textBox1_TextChanged
} //Form1

System.Object
   System.EventArgs
    System.Windows.Forms.LayoutEventArgs

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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, 1.1, 1.0

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