TabControl.DrawItem Evento
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Si verifica se il controllo TabControl deve disegnare ognuna delle proprie schede nel caso in cui la proprietà DrawMode sia impostata su OwnerDrawFixed.
public:
event System::Windows::Forms::DrawItemEventHandler ^ DrawItem;
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 evento
Esempio
Nell'esempio di codice seguente viene creato un oggetto TabControl con un TabPageoggetto . In questo esempio viene dichiarato un gestore eventi utilizzato per disegnare una stringa e Rectangle
nella scheda di tabPage1
. Il gestore eventi è associato all'evento DrawItem
.
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
Commenti
Quando si imposta la proprietà su OwnerDrawFixed, l'evento DrawItemDrawModeTabControl genera ogni volta che deve disegnare una delle relative schede. Per personalizzare l'aspetto delle schede, specificare il proprio codice di disegno in un gestore per l'evento DrawItem .
Non TabControl supporta le dimensioni delle schede delle variabili con il disegno del proprietario.
Per ulteriori informazioni sulla gestione degli eventi, consultare gestione e generazione di eventi.