LayoutEventArgs 类
为 Layout 事件提供数据。无法继承此类。
**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）
语法
声明
Public NotInheritable Class LayoutEventArgs
Inherits EventArgs
用法
Dim instance As LayoutEventArgs
public sealed class LayoutEventArgs : EventArgs
public ref class LayoutEventArgs sealed : public EventArgs
public final class LayoutEventArgs extends EventArgs
public final class LayoutEventArgs extends EventArgs
备注
对控件所做的更改（如调整大小子控件、显示或隐藏子控件以及添加或移除子控件）使控件有必要对其子控件进行布局。LayoutEventArgs 指定已更改的子控件及其影响的属性。例如，如果自上次布局操作后控件已可见，则 Visible 属性受到影响。
如果当调用 PerformLayout 方法时未提供任何值，则 AffectedControl 和 AffectedProperty 属性被设置为 空引用（在 Visual Basic 中为 Nothing）。
有关处理事件的更多信息，请参见 使用事件。
示例
下面的代码示例将 AffectedProperty 和 AffectedControl 属性作为 LayoutEventHandler 参数使用，通过对 Windows 窗体和控件进行各种属性更改来调整 Windows 窗体及其控件的大小。
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 : 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();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
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.Anchor = System.Windows.Forms.AnchorStyles.Bottom;
this.layoutButton.Location = new System.Drawing.Point(72, 88);
this.layoutButton.Name = "layoutButton";
this.layoutButton.Size = new System.Drawing.Size(150, 23);
this.layoutButton.TabIndex = 0;
this.layoutButton.Text = "Hello";
//
// textBox1
//
this.textBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.textBox1.Location = new System.Drawing.Point(24, 40);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(248, 20);
this.textBox1.TabIndex = 1;
this.textBox1.Text = "Hello";
this.textBox1.TextChanged += new System.EventHandler(this.textBox1_TextChanged);
//
// label1
//
this.label1.Location = new System.Drawing.Point(24, 16);
this.label1.Name = "label1";
this.label1.TabIndex = 2;
this.label1.Text = "Button\'s Text:";
//
// Form1
//
this.ClientSize = new System.Drawing.Size(292, 129);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.label1,
this.textBox1,
this.layoutButton});
this.Name = "Form1";
this.Text = "Layout Sample";
this.Layout += new System.Windows.Forms.LayoutEventHandler(this.Form1_Layout);
this.ResumeLayout(false);
}
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
// 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.AffectedControl != null) && (e.AffectedProperty != null))
{
// Ensure that the affected property is the Bounds property
// of the form.
if (e.AffectedProperty.ToString() == "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.Width + 50) > 300)
{
this.Width = this.layoutButton.Width + 50;
}
// If not, keep the form's width at 300 pixels.
else
{
this.Width = 300;
}
// Center layoutButton on the form.
this.layoutButton.Left = (this.ClientSize.Width - this.layoutButton.Width) / 2;
}
}
}
// 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.Text = this.textBox1.Text;
// Get the width of the text using the proper font.
int textWidth = (int)this.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)
{
// Setting the size property on any control raises
// the Layout event for its container.
this.layoutButton.Width = textWidth + 20;
}
// If not, keep layoutButton's width at 150 pixels.
else
{
this.layoutButton.Width = 150;
}
}
}
public ref class Form1: public System::Windows::Forms::Form
{
private:
System::Windows::Forms::TextBox^ textBox1;
System::Windows::Forms::Label ^ label1;
System::Windows::Forms::Button^ layoutButton;
System::ComponentModel::Container^ components;
public:
Form1()
{
InitializeComponent();
}
protected:
~Form1()
{
if ( components != nullptr )
{
delete components;
}
}
private:
void InitializeComponent()
{
this->layoutButton = gcnew System::Windows::Forms::Button;
this->textBox1 = gcnew System::Windows::Forms::TextBox;
this->label1 = gcnew System::Windows::Forms::Label;
this->SuspendLayout();
//
// layoutButton
//
this->layoutButton->Anchor = System::Windows::Forms::AnchorStyles::Bottom;
this->layoutButton->Location = System::Drawing::Point( 72, 88 );
this->layoutButton->Name = "layoutButton";
this->layoutButton->Size = System::Drawing::Size( 150, 23 );
this->layoutButton->TabIndex = 0;
this->layoutButton->Text = "Hello";
//
// textBox1
//
this->textBox1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(System::Windows::Forms::AnchorStyles::Top | System::Windows::Forms::AnchorStyles::Left | System::Windows::Forms::AnchorStyles::Right);
this->textBox1->Location = System::Drawing::Point( 24, 40 );
this->textBox1->Name = "textBox1";
this->textBox1->Size = System::Drawing::Size( 248, 20 );
this->textBox1->TabIndex = 1;
this->textBox1->Text = "Hello";
this->textBox1->TextChanged += gcnew System::EventHandler( this, &Form1::textBox1_TextChanged );
//
// label1
//
this->label1->Location = System::Drawing::Point( 24, 16 );
this->label1->Name = "label1";
this->label1->TabIndex = 2;
this->label1->Text = "Button's Text:";
//
// Form1
//
this->ClientSize = System::Drawing::Size( 292, 129 );
array<System::Windows::Forms::Control^>^temp0 = {this->label1,this->textBox1,this->layoutButton};
this->Controls->AddRange( temp0 );
this->Name = "Form1";
this->Text = "Layout Sample";
this->Layout += gcnew System::Windows::Forms::LayoutEventHandler( this, &Form1::Form1_Layout );
this->ResumeLayout( false );
}
// 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.
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->AffectedControl != nullptr) && (e->AffectedProperty != nullptr) )
{
// Ensure that the affected property is the Bounds property
// of the form.
if ( e->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->Width + 50) > 300 )
{
this->Width = this->layoutButton->Width + 50;
}
// If not, keep the form's width at 300 pixels.
else
{
this->Width = 300;
}
// Center layoutButton on the form.
this->layoutButton->Left = (this->ClientSize.Width - this->layoutButton->Width) / 2;
}
}
}
// 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.
void textBox1_TextChanged( Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Set the Text property of layoutButton.
this->layoutButton->Text = this->textBox1->Text;
// Get the width of the text using the proper font.
int textWidth = (int)this->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 )
{
// Setting the size property on any control raises
// the Layout event for its container.
this->layoutButton->Width = textWidth + 20;
}
// If not, keep layoutButton's width at 150 pixels.
else
{
this->layoutButton->Width = 150;
}
}
};
[STAThread]
int main()
{
Application::Run( gcnew Form1 );
}
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
继承层次结构
System.Object
System.EventArgs
System.Windows.Forms.LayoutEventArgs
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
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
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
请参见
参考
LayoutEventArgs 成员
System.Windows.Forms 命名空间
LayoutEventHandler
AffectedProperty
AffectedControl
Control.Layout 事件