LayoutEventArgs 类

定义

Layout 事件提供数据。Provides data for the Layout event. 此类不能被继承。This class cannot be inherited.

public ref class LayoutEventArgs sealed : EventArgs
public sealed class LayoutEventArgs : EventArgs
type LayoutEventArgs = class
    inherit EventArgs
Public NotInheritable Class LayoutEventArgs
Inherits EventArgs
继承
LayoutEventArgs

示例

下面的代码示例使用AffectedPropertyAffectedControl属性作为LayoutEventHandler参数, 通过对 windows 窗体和控件的各种属性更改来协调 windows 窗体及其控件的大小。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 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 : 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 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 (components IsNot 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 (e.AffectedControl IsNot Nothing) And (e.AffectedProperty IsNot 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

注解

更改控件 (如调整大小、显示或隐藏子控件, 以及添加或删除子控件) 使控件可以布局其子控件。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. LayoutEventArgs指定已更改的子控件及其受影响的属性。A LayoutEventArgs specifies the child control that has been changed and its affected property. 例如, 如果控件自上次布局操作后变为可见, 则Visible属性会受到影响。For example, if a control has been made visible since the last layout operation, the Visible property is affected.

如果调用AffectedProperty AffectedControl 方法时PerformLayout未提供null任何值, 则和属性设置为。The AffectedControl and AffectedProperty properties are set to null if no values were provided when the PerformLayout method was called.

有关处理事件的详细信息, 请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.

构造函数

LayoutEventArgs(Control, String)

用指定的控件和受影响的属性初始化 LayoutEventArgs 类的新实例。Initializes a new instance of the LayoutEventArgs class with the specified control and property affected.

LayoutEventArgs(IComponent, String)

使用指定的组件和受影响的属性初始化 LayoutEventArgs 类的新实例。Initializes a new instance of the LayoutEventArgs class with the specified component and property affected.

属性

AffectedComponent

获取受此布局更改影响的 ComponentGets the Component affected by the layout change.

AffectedControl

获取受此更改影响的控件。Gets the child control affected by the change.

AffectedProperty

获取受此更改影响的属性。Gets the property affected by the change.

方法

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)

适用于

另请参阅