TabControl.DrawItem Evento

Definición

Espacio de nombres:

System.Windows.Forms

Ensamblado:

System.Windows.Forms.dll

Se produce cuando TabControl necesita dibujar cada una de sus fichas al establecer la propiedad DrawMode en OwnerDrawFixed.

public:
 event System::Windows::Forms::DrawItemEventHandler ^ DrawItem;

public event System.Windows.Forms.DrawItemEventHandler? DrawItem;

member this.DrawItem : System.Windows.Forms.DrawItemEventHandler 

Public Custom Event DrawItem As DrawItemEventHandler 

Tipo de evento

DrawItemEventHandler

Ejemplos

En el ejemplo de código siguiente se crea un objeto TabControl con uno TabPage. En este ejemplo se declara un controlador de eventos que se usa para dibujar una cadena y Rectangle en la pestaña de tabPage1. El controlador de eventos está enlazado al DrawItem evento.

using namespace System::Drawing;
using namespace System::Windows::Forms;
public ref class Form1: public Form
{
private:
   Rectangle tabArea;
   RectangleF tabTextArea;

public:
   Form1()
   {
      TabControl^ tabControl1 = gcnew TabControl;
      TabPage^ tabPage1 = gcnew TabPage;
      
      // Allows access to the DrawItem event.
      tabControl1->DrawMode = TabDrawMode::OwnerDrawFixed;
      tabControl1->SizeMode = TabSizeMode::Fixed;
      tabControl1->Controls->Add( tabPage1 );
      tabControl1->ItemSize = System::Drawing::Size( 80, 30 );
      tabControl1->Location = Point(25,25);
      tabControl1->Size = System::Drawing::Size( 250, 250 );
      tabPage1->TabIndex = 0;
      ClientSize = System::Drawing::Size( 300, 300 );
      Controls->Add( tabControl1 );
      tabArea = tabControl1->GetTabRect( 0 );
      tabTextArea = tabControl1->GetTabRect( 0 );
      
      // Binds the event handler DrawOnTab to the DrawItem event
      // through the DrawItemEventHandler delegate.
      tabControl1->DrawItem += gcnew DrawItemEventHandler( this, &Form1::DrawOnTab );
   }


private:

   // Declares the event handler DrawOnTab which is a method that
   // draws a String* and Rectangle on the tabPage1 tab.
   void DrawOnTab( Object^ /*sender*/, DrawItemEventArgs^ e )
   {
      Graphics^ g = e->Graphics;
      Pen^ p = gcnew Pen( Color::Blue );
      System::Drawing::Font^ font = gcnew System::Drawing::Font( "Arial",10.0f );
      SolidBrush^ brush = gcnew SolidBrush( Color::Red );
      g->DrawRectangle( p, tabArea );
      g->DrawString( "tabPage1", font, brush, tabTextArea );
   }

};

int main()
{
   Application::Run( gcnew Form1 );
}

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

public class Form1 : Form
{
    private Rectangle tabArea;
    private RectangleF tabTextArea;

    public Form1()
    {
        TabControl tabControl1 = new TabControl();
        TabPage tabPage1 = new TabPage();

        // Allows access to the DrawItem event. 
        tabControl1.DrawMode = TabDrawMode.OwnerDrawFixed;

        tabControl1.SizeMode = TabSizeMode.Fixed;
        tabControl1.Controls.Add(tabPage1);
        tabControl1.ItemSize = new Size(80, 30);
        tabControl1.Location = new Point(25, 25);
        tabControl1.Size = new Size(250, 250);
        tabPage1.TabIndex = 0;
        ClientSize = new Size(300, 300);
        Controls.Add(tabControl1);

        tabArea = tabControl1.GetTabRect(0);
        tabTextArea = (RectangleF)tabControl1.GetTabRect(0);

        // Binds the event handler DrawOnTab to the DrawItem event 
        // through the DrawItemEventHandler delegate.
        tabControl1.DrawItem += new DrawItemEventHandler(DrawOnTab);
    }

    // Declares the event handler DrawOnTab which is a method that
    // draws a string and Rectangle on the tabPage1 tab.
    private void DrawOnTab(object sender, DrawItemEventArgs e)
    {
        Graphics g = e.Graphics;
        Pen p = new Pen(Color.Blue);
        Font font = new Font("Arial", 10.0f);
        SolidBrush brush = new SolidBrush(Color.Red);

        g.DrawRectangle(p, tabArea);
        g.DrawString("tabPage1", font, brush, tabTextArea);
    }

    static void Main() 
    {
        Application.Run(new Form1());
    }
}

Imports System.Drawing
Imports System.Windows.Forms

Public Class Form1
    Inherits Form
    Private tabArea As Rectangle
    Private tabTextArea As RectangleF

    Public Sub New()
        Dim tabControl1 As New TabControl()
        Dim tabPage1 As New TabPage()

        ' Allows access to the DrawItem event. 
        tabControl1.DrawMode = TabDrawMode.OwnerDrawFixed

        tabControl1.SizeMode = TabSizeMode.Fixed
        tabControl1.Controls.Add(tabPage1)
        tabControl1.ItemSize = New Size(80, 30)
        tabControl1.Location = New Point(25, 25)
        tabControl1.Size = New Size(250, 250)
        tabPage1.TabIndex = 0
        ClientSize = New Size(300, 300)
        Controls.Add(tabControl1)

        tabArea = tabControl1.GetTabRect(0)
        tabTextArea = RectangleF.op_Implicit(tabControl1.GetTabRect(0))

        ' Binds the event handler DrawOnTab to the DrawItem event 
        ' through the DrawItemEventHandler delegate.
        AddHandler tabControl1.DrawItem, AddressOf DrawOnTab
    End Sub

    ' Declares the event handler DrawOnTab which is a method that
    ' draws a string and Rectangle on the tabPage1 tab.
    Private Sub DrawOnTab(ByVal sender As Object, ByVal e As DrawItemEventArgs)
        Dim g As Graphics = e.Graphics
        Dim p As New Pen(Color.Blue)
        Dim font As New Font("Arial", 10.0F)
        Dim brush As New SolidBrush(Color.Red)

        g.DrawRectangle(p, tabArea)
        g.DrawString("tabPage1", font, brush, tabTextArea)
    End Sub

    Shared Sub Main()
        Application.Run(New Form1())
    End Sub
End Class

Comentarios

Cuando se establece la DrawMode propiedad OwnerDrawFixeden , TabControl genera el DrawItem evento siempre que necesite pintar una de sus pestañas. Para personalizar la apariencia de las pestañas, proporcione su propio código de pintura en un controlador para el DrawItem evento.

TabControl No admite tamaños de tabulación variables con el dibujo del propietario.

Para obtener más información sobre el manejo de eventos, consulte controlar y provocar eventos.

Consulte también

• DrawItemEventHandler
• OnDrawItem(DrawItemEventArgs)