Control.PerformLayout Metodo

public:
 void PerformLayout();

public void PerformLayout();

member this.PerformLayout : unit -> unit

Public Sub PerformLayout ()

Esempio

Nell'esempio di codice seguente viene illustrato come usare il PerformLayout metodo . Illustra anche i modi in cui viene generato l'evento Layout . In questo esempio, il Click gestore eventi per Button1 chiama in modo esplicito PerformLayout. Il Click gestore eventi per Button2 chiama PerformLayoutin modo implicito . PerformLayout viene chiamato anche quando il modulo viene caricato. Button3 restituisce il controllo allo stato in cui si trovava durante il caricamento. In ogni caso, viene generato l'evento Layout .

Questo è un esempio completo. Per eseguire l'esempio, incollare il codice seguente in un modulo vuoto.

using namespace System;
using namespace System::Windows::Forms;
using namespace System::Drawing;

// This custom control has the Layout event implented so that when 
// PerformLayout(AffectedControl, AffectedProperty) is called 
// on the control, where AffectedProperty equals "Bounds" the 
// textbox is centered on the control.
public ref class LayoutControl: public System::Windows::Forms::UserControl
{
public private:
   System::Windows::Forms::TextBox^ TextBox1;

public:
   LayoutControl()
      : UserControl()
   {
      InitializeComponent();
   }


private:
   void InitializeComponent()
   {
      this->TextBox1 = gcnew System::Windows::Forms::TextBox;
      this->SuspendLayout();
      this->TextBox1->BorderStyle = System::Windows::Forms::BorderStyle::FixedSingle;
      this->TextBox1->Name = "TextBox1";
      this->TextBox1->TabIndex = 0;
      this->BackColor = System::Drawing::SystemColors::ControlDark;
      this->Controls->Add( this->TextBox1 );
      this->Name = "LayoutControl";
      this->ResumeLayout( false );
      this->Layout += gcnew LayoutEventHandler( this, &LayoutControl::LayoutControl_Layout );
   }


   // This method is called when the Layout event is fired. 
   // This happens by during the initial load, by calling PerformLayout
   // or by resizing, adding or removing controls or other actions that 
   // affect how the control is laid out. This method checks the 
   // value of e.AffectedProperty and changes the look of the 
   // control accordingly. 
   void LayoutControl_Layout( Object^ /*sender*/, System::Windows::Forms::LayoutEventArgs^ e )
   {
      if ( e->AffectedProperty != nullptr )
      {
         if ( e->AffectedProperty->Equals( "Bounds" ) )
         {
            TextBox1->Left = (this->Width - TextBox1->Width) / 2;
            TextBox1->Top = (this->Height - TextBox1->Height) / 2;
         }
      }
      else
      {
         this->Size = System::Drawing::Size( 150, 160 );
         TextBox1->Location = System::Drawing::Point( 16, 24 );
      }

      TextBox1->Text = String::Format( "Left = {0} Top = {1}", TextBox1->Left, TextBox1->Top );
   }

};

public ref class LayoutForm: public System::Windows::Forms::Form
{
public:
   LayoutForm()
      : Form()
   {
      InitializeComponent();
   }


public private:
   System::Windows::Forms::Button^ Button1;
   System::Windows::Forms::Button^ Button2;
   LayoutControl^ LayoutControl1;
   System::Windows::Forms::Button^ Button3;

private:
   void InitializeComponent()
   {
      this->Button1 = gcnew System::Windows::Forms::Button;
      this->Button2 = gcnew System::Windows::Forms::Button;
      this->Button3 = gcnew System::Windows::Forms::Button;
      this->LayoutControl1 = gcnew LayoutControl;
      this->SuspendLayout();
      this->Button1->Location = System::Drawing::Point( 16, 16 );
      this->Button1->Name = "Button1";
      this->Button1->Size = System::Drawing::Size( 120, 32 );
      this->Button1->TabIndex = 0;
      this->Button1->Text = "Center textbox on control";
      this->Button2->Location = System::Drawing::Point( 152, 16 );
      this->Button2->Name = "Button2";
      this->Button2->Size = System::Drawing::Size( 104, 32 );
      this->Button2->TabIndex = 3;
      this->Button2->Text = "Shrink user control";
      this->Button3->Location = System::Drawing::Point( 96, 232 );
      this->Button3->Name = "Button3";
      this->Button3->TabIndex = 5;
      this->Button3->Text = "Reset";
      this->LayoutControl1->BackColor = System::Drawing::SystemColors::ControlDark;
      this->LayoutControl1->Location = System::Drawing::Point( 72, 64 );
      this->LayoutControl1->Name = "LayoutControl1";
      this->LayoutControl1->Size = System::Drawing::Size( 150, 160 );
      this->LayoutControl1->TabIndex = 6;
      this->ClientSize = System::Drawing::Size( 292, 266 );
      this->Controls->Add( this->Button3 );
      this->Controls->Add( this->Button2 );
      this->Controls->Add( this->Button1 );
      this->Controls->Add( this->LayoutControl1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
      this->Button1->Click += gcnew System::EventHandler( this,&LayoutForm::Button1_Click );
      this->Button2->Click += gcnew System::EventHandler( this,&LayoutForm::Button2_Click );
      this->Button3->Click += gcnew System::EventHandler( this,&LayoutForm::Button3_Click );
   }


   // This method explicitly calls raises the layout event on 
   // LayoutControl1, changing the Bounds property.
   void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->PerformLayout( LayoutControl1, "Bounds" );
   }


   // This resize of LayoutControl1 implicitly triggers the layout event. 
   //  Changing the size of the control affects its Bounds property.
   void Button2_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->Size = System::Drawing::Size( 100, 100 );
   }


   // This method explicitly calls PerformLayout with no parameters, 
   // which raises the Layout event with the LayoutEventArgs properties
   // equal to Nothing.
   void Button3_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->PerformLayout();
   }

};


[System::STAThread]
int main()
{
   Application::Run( gcnew LayoutForm );
}

using System.Windows.Forms;
using System.Drawing;

public class LayoutForm:
    System.Windows.Forms.Form

{
    public LayoutForm() : base()
    {        
        InitializeComponent();
    }

    internal System.Windows.Forms.Button Button1;
    internal System.Windows.Forms.Button Button2;
    internal LayoutControl LayoutControl1;
    internal System.Windows.Forms.Button Button3;

    private void InitializeComponent()
    {
        this.Button1 = new System.Windows.Forms.Button();
        this.Button2 = new System.Windows.Forms.Button();
        this.Button3 = new System.Windows.Forms.Button();
        this.LayoutControl1 = new LayoutControl();
        this.SuspendLayout();
        this.Button1.Location = new System.Drawing.Point(16, 16);
        this.Button1.Name = "Button1";
        this.Button1.Size = new System.Drawing.Size(120, 32);
        this.Button1.TabIndex = 0;
        this.Button1.Text = "Center textbox on control";
        this.Button2.Location = new System.Drawing.Point(152, 16);
        this.Button2.Name = "Button2";
        this.Button2.Size = new System.Drawing.Size(104, 32);
        this.Button2.TabIndex = 3;
        this.Button2.Text = "Shrink user control";
        this.Button3.Location = new System.Drawing.Point(96, 232);
        this.Button3.Name = "Button3";
        this.Button3.TabIndex = 5;
        this.Button3.Text = "Reset";
        this.LayoutControl1.BackColor = System.Drawing.SystemColors.ControlDark;
        this.LayoutControl1.Location = new System.Drawing.Point(72, 64);
        this.LayoutControl1.Name = "LayoutControl1";
        this.LayoutControl1.Size = new System.Drawing.Size(150, 160);
        this.LayoutControl1.TabIndex = 6;
        this.ClientSize = new System.Drawing.Size(292, 266);
        this.Controls.Add(this.Button3);
        this.Controls.Add(this.Button2);
        this.Controls.Add(this.Button1);
        this.Controls.Add(this.LayoutControl1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
        this.Button1.Click += new System.EventHandler(Button1_Click);
        this.Button2.Click += new System.EventHandler(Button2_Click);
        this.Button3.Click += new System.EventHandler(Button3_Click);
    }

    [System.STAThread]
    public static void Main()
    {
        Application.Run(new LayoutForm());
    }

    // This method explicitly calls raises the layout event on 
    // LayoutControl1, changing the Bounds property.
    private void Button1_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.PerformLayout(LayoutControl1, "Bounds");
    }

    // This resize of LayoutControl1 implicitly triggers the layout event. 
    //  Changing the size of the control affects its Bounds property.
    private void Button2_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.Size = new System.Drawing.Size(100, 100);
    }

    // This method explicitly calls PerformLayout with no parameters, 
    // which raises the Layout event with the LayoutEventArgs properties
    // equal to Nothing.
    private void Button3_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.PerformLayout();
    }
}

// This custom control has the Layout event implented so that when 
// PerformLayout(AffectedControl, AffectedProperty) is called 
// on the control, where AffectedProperty equals "Bounds" the 
// textbox is centered on the control.
public class LayoutControl:
    System.Windows.Forms.UserControl
{
    internal System.Windows.Forms.TextBox TextBox1;

    public LayoutControl() : base()
    {        
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        this.TextBox1 = new System.Windows.Forms.TextBox();
        this.SuspendLayout();
        this.TextBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
        this.TextBox1.Name = "TextBox1";
        this.TextBox1.TabIndex = 0;
        this.BackColor = System.Drawing.SystemColors.ControlDark;
        this.Controls.Add(this.TextBox1);
        this.Name = "LayoutControl";
        this.ResumeLayout(false);
        this.Layout += new LayoutEventHandler(LayoutControl_Layout);
    }

    // This method is called when the Layout event is fired. 
    // This happens by during the initial load, by calling PerformLayout
    // or by resizing, adding or removing controls or other actions that 
    // affect how the control is laid out. This method checks the 
    // value of e.AffectedProperty and changes the look of the 
    // control accordingly. 
    private void LayoutControl_Layout(object sender, 
        System.Windows.Forms.LayoutEventArgs e)
    {
        if (e.AffectedProperty != null)
        {
            if (e.AffectedProperty.Equals("Bounds"))
            {
                TextBox1.Left = (this.Width-TextBox1.Width)/2;
                TextBox1.Top = (this.Height-TextBox1.Height)/2;
            }
        }
        else
        {
            this.Size = new System.Drawing.Size(150, 160);
            TextBox1.Location = new System.Drawing.Point(16, 24);
        }
        TextBox1.Text = "Left = "+TextBox1.Left+" Top = "+TextBox1.Top;
    }
}

Imports System.Windows.Forms
Imports System.Drawing



Public Class LayoutForm
    Inherits System.Windows.Forms.Form

    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub

    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents LayoutControl1 As LayoutControl
    Friend WithEvents Button3 As System.Windows.Forms.Button

    Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.LayoutControl1 = New LayoutControl
        Me.SuspendLayout()
        Me.Button1.Location = New System.Drawing.Point(16, 16)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(120, 32)
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "Center textbox on control"
        Me.Button2.Location = New System.Drawing.Point(152, 16)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(104, 32)
        Me.Button2.TabIndex = 3
        Me.Button2.Text = "Shrink user control"
        Me.Button3.Location = New System.Drawing.Point(96, 232)
        Me.Button3.Name = "Button3"
        Me.Button3.TabIndex = 5
        Me.Button3.Text = "Reset"
        Me.LayoutControl1.BackColor = System.Drawing.SystemColors.ControlDark
        Me.LayoutControl1.Location = New System.Drawing.Point(72, 64)
        Me.LayoutControl1.Name = "LayoutControl1"
        Me.LayoutControl1.Size = New System.Drawing.Size(150, 160)
        Me.LayoutControl1.TabIndex = 6
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.LayoutControl1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

    <System.STAThread()> Shared Sub Main()
        Application.Run(New LayoutForm)
    End Sub


   
    ' This method explicitly calls raises the layout event on 
    ' LayoutControl1, changing the Bounds property.
    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        LayoutControl1.PerformLayout(LayoutControl1, "Bounds")
    End Sub

    ' This resize of LayoutControl1 implicitly triggers the layout event. 
    '   Changing the size of the control affects its Bounds property.
    Private Sub Button2_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button2.Click
        LayoutControl1.Size = New System.Drawing.Size(100, 100)
    End Sub

    ' This method explicitly calls PerformLayout with no parameters, 
    ' which raises the Layout event with the LayoutEventArgs properties
    ' equal to Nothing.
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        LayoutControl1.PerformLayout()
    End Sub

End Class


'This custom control has the Layout event implented so that when 
'PerformLayout(AffectedControl, AffectedProperty) is called on the control, 
'where AffectedProperty equals "Bounds" the textbox is centered on the control.
Public Class LayoutControl
    Inherits System.Windows.Forms.UserControl
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox

    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub

    Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        Me.TextBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.TabIndex = 0
        Me.BackColor = System.Drawing.SystemColors.ControlDark
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "LayoutControl"
        Me.ResumeLayout(False)

    End Sub

    'This method is called when the Layout event is fired. This happens by during the initial load,
    'by calling PerformLayout or by resizing, adding or removing controls or other actions that 
    'affect how the control is laid out. This method checks the value of e.AffectedProperty
    'and changes the look of the control accordingly. 
    Private Sub LayoutControl_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles MyBase.Layout
        If e.AffectedProperty IsNot Nothing Then
            If e.AffectedProperty.Equals("Bounds") Then
                TextBox1.Left = (Me.Width - TextBox1.Width) / 2
                TextBox1.Top = (Me.Height - TextBox1.Height) / 2
            End If
        Else
            Me.Size = New System.Drawing.Size(150, 160)
            TextBox1.Location = New System.Drawing.Point(16, 24)
        End If
        TextBox1.Text = "Left = " & TextBox1.Left & " Top = " & TextBox1.Top
    End Sub

End Class

Commenti

Se il SuspendLayout metodo è stato chiamato prima di chiamare il PerformLayout metodo , l'evento Layout viene eliminato.

Le AffectedControl proprietà e AffectedProperty dell'oggetto LayoutEventArgs creato vengono impostate su null se non sono stati forniti valori quando è stato chiamato il PerformLayout metodo .

Vedi anche

• ResumeLayout()
• LayoutEngine
• Layout
• PerformLayout()
• SuspendLayout()
• InitLayout()
• BackgroundImageLayout

public:
 void PerformLayout(System::Windows::Forms::Control ^ affectedControl, System::String ^ affectedProperty);

public void PerformLayout(System.Windows.Forms.Control affectedControl, string affectedProperty);

member this.PerformLayout : System.Windows.Forms.Control * string -> unit

Public Sub PerformLayout (affectedControl As Control, affectedProperty As String)

Parametri

Esempio

Nell'esempio di codice seguente viene illustrato come usare il PerformLayout metodo . Illustra anche i modi in cui viene generato l'evento Layout . In questo esempio, il Click gestore eventi per Button1 chiama in modo esplicito PerformLayout. Il Click gestore eventi per Button2 chiama PerformLayoutin modo implicito . PerformLayout viene chiamato anche quando il modulo viene caricato. Button3 restituisce il controllo allo stato in cui si trovava durante il caricamento. In ogni caso, viene generato l'evento Layout .

Questo è un esempio completo. Per eseguire l'esempio, incollare il codice seguente in un modulo vuoto.

using namespace System;
using namespace System::Windows::Forms;
using namespace System::Drawing;

// This custom control has the Layout event implented so that when 
// PerformLayout(AffectedControl, AffectedProperty) is called 
// on the control, where AffectedProperty equals "Bounds" the 
// textbox is centered on the control.
public ref class LayoutControl: public System::Windows::Forms::UserControl
{
public private:
   System::Windows::Forms::TextBox^ TextBox1;

public:
   LayoutControl()
      : UserControl()
   {
      InitializeComponent();
   }


private:
   void InitializeComponent()
   {
      this->TextBox1 = gcnew System::Windows::Forms::TextBox;
      this->SuspendLayout();
      this->TextBox1->BorderStyle = System::Windows::Forms::BorderStyle::FixedSingle;
      this->TextBox1->Name = "TextBox1";
      this->TextBox1->TabIndex = 0;
      this->BackColor = System::Drawing::SystemColors::ControlDark;
      this->Controls->Add( this->TextBox1 );
      this->Name = "LayoutControl";
      this->ResumeLayout( false );
      this->Layout += gcnew LayoutEventHandler( this, &LayoutControl::LayoutControl_Layout );
   }


   // This method is called when the Layout event is fired. 
   // This happens by during the initial load, by calling PerformLayout
   // or by resizing, adding or removing controls or other actions that 
   // affect how the control is laid out. This method checks the 
   // value of e.AffectedProperty and changes the look of the 
   // control accordingly. 
   void LayoutControl_Layout( Object^ /*sender*/, System::Windows::Forms::LayoutEventArgs^ e )
   {
      if ( e->AffectedProperty != nullptr )
      {
         if ( e->AffectedProperty->Equals( "Bounds" ) )
         {
            TextBox1->Left = (this->Width - TextBox1->Width) / 2;
            TextBox1->Top = (this->Height - TextBox1->Height) / 2;
         }
      }
      else
      {
         this->Size = System::Drawing::Size( 150, 160 );
         TextBox1->Location = System::Drawing::Point( 16, 24 );
      }

      TextBox1->Text = String::Format( "Left = {0} Top = {1}", TextBox1->Left, TextBox1->Top );
   }

};

public ref class LayoutForm: public System::Windows::Forms::Form
{
public:
   LayoutForm()
      : Form()
   {
      InitializeComponent();
   }


public private:
   System::Windows::Forms::Button^ Button1;
   System::Windows::Forms::Button^ Button2;
   LayoutControl^ LayoutControl1;
   System::Windows::Forms::Button^ Button3;

private:
   void InitializeComponent()
   {
      this->Button1 = gcnew System::Windows::Forms::Button;
      this->Button2 = gcnew System::Windows::Forms::Button;
      this->Button3 = gcnew System::Windows::Forms::Button;
      this->LayoutControl1 = gcnew LayoutControl;
      this->SuspendLayout();
      this->Button1->Location = System::Drawing::Point( 16, 16 );
      this->Button1->Name = "Button1";
      this->Button1->Size = System::Drawing::Size( 120, 32 );
      this->Button1->TabIndex = 0;
      this->Button1->Text = "Center textbox on control";
      this->Button2->Location = System::Drawing::Point( 152, 16 );
      this->Button2->Name = "Button2";
      this->Button2->Size = System::Drawing::Size( 104, 32 );
      this->Button2->TabIndex = 3;
      this->Button2->Text = "Shrink user control";
      this->Button3->Location = System::Drawing::Point( 96, 232 );
      this->Button3->Name = "Button3";
      this->Button3->TabIndex = 5;
      this->Button3->Text = "Reset";
      this->LayoutControl1->BackColor = System::Drawing::SystemColors::ControlDark;
      this->LayoutControl1->Location = System::Drawing::Point( 72, 64 );
      this->LayoutControl1->Name = "LayoutControl1";
      this->LayoutControl1->Size = System::Drawing::Size( 150, 160 );
      this->LayoutControl1->TabIndex = 6;
      this->ClientSize = System::Drawing::Size( 292, 266 );
      this->Controls->Add( this->Button3 );
      this->Controls->Add( this->Button2 );
      this->Controls->Add( this->Button1 );
      this->Controls->Add( this->LayoutControl1 );
      this->Name = "Form1";
      this->Text = "Form1";
      this->ResumeLayout( false );
      this->Button1->Click += gcnew System::EventHandler( this,&LayoutForm::Button1_Click );
      this->Button2->Click += gcnew System::EventHandler( this,&LayoutForm::Button2_Click );
      this->Button3->Click += gcnew System::EventHandler( this,&LayoutForm::Button3_Click );
   }


   // This method explicitly calls raises the layout event on 
   // LayoutControl1, changing the Bounds property.
   void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->PerformLayout( LayoutControl1, "Bounds" );
   }


   // This resize of LayoutControl1 implicitly triggers the layout event. 
   //  Changing the size of the control affects its Bounds property.
   void Button2_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->Size = System::Drawing::Size( 100, 100 );
   }


   // This method explicitly calls PerformLayout with no parameters, 
   // which raises the Layout event with the LayoutEventArgs properties
   // equal to Nothing.
   void Button3_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
   {
      LayoutControl1->PerformLayout();
   }

};


[System::STAThread]
int main()
{
   Application::Run( gcnew LayoutForm );
}

using System.Windows.Forms;
using System.Drawing;

public class LayoutForm:
    System.Windows.Forms.Form

{
    public LayoutForm() : base()
    {        
        InitializeComponent();
    }

    internal System.Windows.Forms.Button Button1;
    internal System.Windows.Forms.Button Button2;
    internal LayoutControl LayoutControl1;
    internal System.Windows.Forms.Button Button3;

    private void InitializeComponent()
    {
        this.Button1 = new System.Windows.Forms.Button();
        this.Button2 = new System.Windows.Forms.Button();
        this.Button3 = new System.Windows.Forms.Button();
        this.LayoutControl1 = new LayoutControl();
        this.SuspendLayout();
        this.Button1.Location = new System.Drawing.Point(16, 16);
        this.Button1.Name = "Button1";
        this.Button1.Size = new System.Drawing.Size(120, 32);
        this.Button1.TabIndex = 0;
        this.Button1.Text = "Center textbox on control";
        this.Button2.Location = new System.Drawing.Point(152, 16);
        this.Button2.Name = "Button2";
        this.Button2.Size = new System.Drawing.Size(104, 32);
        this.Button2.TabIndex = 3;
        this.Button2.Text = "Shrink user control";
        this.Button3.Location = new System.Drawing.Point(96, 232);
        this.Button3.Name = "Button3";
        this.Button3.TabIndex = 5;
        this.Button3.Text = "Reset";
        this.LayoutControl1.BackColor = System.Drawing.SystemColors.ControlDark;
        this.LayoutControl1.Location = new System.Drawing.Point(72, 64);
        this.LayoutControl1.Name = "LayoutControl1";
        this.LayoutControl1.Size = new System.Drawing.Size(150, 160);
        this.LayoutControl1.TabIndex = 6;
        this.ClientSize = new System.Drawing.Size(292, 266);
        this.Controls.Add(this.Button3);
        this.Controls.Add(this.Button2);
        this.Controls.Add(this.Button1);
        this.Controls.Add(this.LayoutControl1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
        this.Button1.Click += new System.EventHandler(Button1_Click);
        this.Button2.Click += new System.EventHandler(Button2_Click);
        this.Button3.Click += new System.EventHandler(Button3_Click);
    }

    [System.STAThread]
    public static void Main()
    {
        Application.Run(new LayoutForm());
    }

    // This method explicitly calls raises the layout event on 
    // LayoutControl1, changing the Bounds property.
    private void Button1_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.PerformLayout(LayoutControl1, "Bounds");
    }

    // This resize of LayoutControl1 implicitly triggers the layout event. 
    //  Changing the size of the control affects its Bounds property.
    private void Button2_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.Size = new System.Drawing.Size(100, 100);
    }

    // This method explicitly calls PerformLayout with no parameters, 
    // which raises the Layout event with the LayoutEventArgs properties
    // equal to Nothing.
    private void Button3_Click(System.Object sender, System.EventArgs e)
    {
        LayoutControl1.PerformLayout();
    }
}

// This custom control has the Layout event implented so that when 
// PerformLayout(AffectedControl, AffectedProperty) is called 
// on the control, where AffectedProperty equals "Bounds" the 
// textbox is centered on the control.
public class LayoutControl:
    System.Windows.Forms.UserControl
{
    internal System.Windows.Forms.TextBox TextBox1;

    public LayoutControl() : base()
    {        
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        this.TextBox1 = new System.Windows.Forms.TextBox();
        this.SuspendLayout();
        this.TextBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
        this.TextBox1.Name = "TextBox1";
        this.TextBox1.TabIndex = 0;
        this.BackColor = System.Drawing.SystemColors.ControlDark;
        this.Controls.Add(this.TextBox1);
        this.Name = "LayoutControl";
        this.ResumeLayout(false);
        this.Layout += new LayoutEventHandler(LayoutControl_Layout);
    }

    // This method is called when the Layout event is fired. 
    // This happens by during the initial load, by calling PerformLayout
    // or by resizing, adding or removing controls or other actions that 
    // affect how the control is laid out. This method checks the 
    // value of e.AffectedProperty and changes the look of the 
    // control accordingly. 
    private void LayoutControl_Layout(object sender, 
        System.Windows.Forms.LayoutEventArgs e)
    {
        if (e.AffectedProperty != null)
        {
            if (e.AffectedProperty.Equals("Bounds"))
            {
                TextBox1.Left = (this.Width-TextBox1.Width)/2;
                TextBox1.Top = (this.Height-TextBox1.Height)/2;
            }
        }
        else
        {
            this.Size = new System.Drawing.Size(150, 160);
            TextBox1.Location = new System.Drawing.Point(16, 24);
        }
        TextBox1.Text = "Left = "+TextBox1.Left+" Top = "+TextBox1.Top;
    }
}

Imports System.Windows.Forms
Imports System.Drawing



Public Class LayoutForm
    Inherits System.Windows.Forms.Form

    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub

    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents LayoutControl1 As LayoutControl
    Friend WithEvents Button3 As System.Windows.Forms.Button

    Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.LayoutControl1 = New LayoutControl
        Me.SuspendLayout()
        Me.Button1.Location = New System.Drawing.Point(16, 16)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(120, 32)
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "Center textbox on control"
        Me.Button2.Location = New System.Drawing.Point(152, 16)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(104, 32)
        Me.Button2.TabIndex = 3
        Me.Button2.Text = "Shrink user control"
        Me.Button3.Location = New System.Drawing.Point(96, 232)
        Me.Button3.Name = "Button3"
        Me.Button3.TabIndex = 5
        Me.Button3.Text = "Reset"
        Me.LayoutControl1.BackColor = System.Drawing.SystemColors.ControlDark
        Me.LayoutControl1.Location = New System.Drawing.Point(72, 64)
        Me.LayoutControl1.Name = "LayoutControl1"
        Me.LayoutControl1.Size = New System.Drawing.Size(150, 160)
        Me.LayoutControl1.TabIndex = 6
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.LayoutControl1)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

    <System.STAThread()> Shared Sub Main()
        Application.Run(New LayoutForm)
    End Sub


   
    ' This method explicitly calls raises the layout event on 
    ' LayoutControl1, changing the Bounds property.
    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        LayoutControl1.PerformLayout(LayoutControl1, "Bounds")
    End Sub

    ' This resize of LayoutControl1 implicitly triggers the layout event. 
    '   Changing the size of the control affects its Bounds property.
    Private Sub Button2_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button2.Click
        LayoutControl1.Size = New System.Drawing.Size(100, 100)
    End Sub

    ' This method explicitly calls PerformLayout with no parameters, 
    ' which raises the Layout event with the LayoutEventArgs properties
    ' equal to Nothing.
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        LayoutControl1.PerformLayout()
    End Sub

End Class


'This custom control has the Layout event implented so that when 
'PerformLayout(AffectedControl, AffectedProperty) is called on the control, 
'where AffectedProperty equals "Bounds" the textbox is centered on the control.
Public Class LayoutControl
    Inherits System.Windows.Forms.UserControl
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox

    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub

    Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.SuspendLayout()
        Me.TextBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.TabIndex = 0
        Me.BackColor = System.Drawing.SystemColors.ControlDark
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "LayoutControl"
        Me.ResumeLayout(False)

    End Sub

    'This method is called when the Layout event is fired. This happens by during the initial load,
    'by calling PerformLayout or by resizing, adding or removing controls or other actions that 
    'affect how the control is laid out. This method checks the value of e.AffectedProperty
    'and changes the look of the control accordingly. 
    Private Sub LayoutControl_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles MyBase.Layout
        If e.AffectedProperty IsNot Nothing Then
            If e.AffectedProperty.Equals("Bounds") Then
                TextBox1.Left = (Me.Width - TextBox1.Width) / 2
                TextBox1.Top = (Me.Height - TextBox1.Height) / 2
            End If
        Else
            Me.Size = New System.Drawing.Size(150, 160)
            TextBox1.Location = New System.Drawing.Point(16, 24)
        End If
        TextBox1.Text = "Left = " & TextBox1.Left & " Top = " & TextBox1.Top
    End Sub

End Class

Commenti

Se il SuspendLayout metodo è stato chiamato prima di chiamare il PerformLayout metodo , l'evento Layout viene eliminato.

I affectedControl parametri e affectedProperty possono essere entrambi impostati su null. In questo modo, le AffectedControl proprietà e AffectedProperty dell'oggetto LayoutEventArgs creato devono essere impostate su null.

Vedi anche

• ResumeLayout()
• LayoutEngine
• Layout
• PerformLayout()
• SuspendLayout()
• InitLayout()
• BackgroundImageLayout