DrawItemEventHandler 代理人

定義

名前空間:

System.Windows.Forms

アセンブリ:

System.Windows.Forms.dll

ComboBox、ListBox、MenuItem、TabControl の各コントロールのいずれかの DrawItem イベントを処理するメソッドを表します

public delegate void DrawItemEventHandler(System::Object ^ sender, DrawItemEventArgs ^ e);

public delegate void DrawItemEventHandler(object? sender, DrawItemEventArgs e);

type DrawItemEventHandler = delegate of obj * DrawItemEventArgs -> unit

Public Delegate Sub DrawItemEventHandler(sender As Object, e As DrawItemEventArgs)

パラメーター

sender

Object

イベントのソース。

e

DrawItemEventArgs

イベント データを格納している DrawItemEventArgs。

例

次のコード例は、所有者が描画したメニュー項目を含むメニューを示しています。 この例では、 AddHandler ステートメントと 演算子を AddressOf 使用して、イベントを処理するデリゲートを MenuItem.DrawItem 指定します。 この例を実行するには、System、System.Windows.Forms、および System.Drawing 名前空間をインポートするフォームに貼り付けます。 すべてのイベントがイベント処理メソッドに関連付けられていることを確認します。

internal:
   // Declare the MainMenu control.
   System::Windows::Forms::MainMenu^ MainMenu1;

   // Declare MenuItem2 as With-Events because it will be user drawn.
   System::Windows::Forms::MenuItem^ MenuItem2;

private:
   void InitializeMenu()
   {
      
      // Create MenuItem1, which will be drawn by the operating system.
      MenuItem^ MenuItem1 = gcnew MenuItem( "Regular Menu Item" );
      
      // Create MenuItem2.
      MenuItem2 = gcnew MenuItem( "Custom Menu Item" );
      
      // Set OwnerDraw property to true. This requires handling the
      // DrawItem event for this menu item.
      MenuItem2->OwnerDraw = true;
      
      //Add the event-handler delegate to handle the DrawItem event.
      MenuItem2->DrawItem += gcnew DrawItemEventHandler( this, &Form1::DrawCustomMenuItem );
      
      // Add the items to the menu.
      array<MenuItem^>^temp0 = {MenuItem1,MenuItem2};
      MainMenu1 = gcnew MainMenu( temp0 );
      
      // Add the menu to the form.
      this->Menu = this->MainMenu1;
   }

   // Draw the custom menu item.
   void DrawCustomMenuItem( Object^ sender, DrawItemEventArgs^ e )
   {
      // Cast the sender to MenuItem so you can access text property.
      MenuItem^ customItem = dynamic_cast<MenuItem^>(sender);
      
      // Create a Brush and a Font to draw the MenuItem.
      System::Drawing::Brush^ aBrush = System::Drawing::Brushes::DarkMagenta;
      System::Drawing::Font^ aFont = gcnew System::Drawing::Font( "Garamond",10,FontStyle::Italic,GraphicsUnit::Point );
      
      // Get the size of the text to use later to draw an ellipse
      // around the item.
      SizeF stringSize = e->Graphics->MeasureString( customItem->Text, aFont );
      
      // Draw the item and then draw the ellipse.
      e->Graphics->DrawString( customItem->Text, aFont, aBrush, (float)e->Bounds.X, (float)e->Bounds.Y );
      e->Graphics->DrawEllipse( gcnew Pen( System::Drawing::Color::Black,2 ), Rectangle(e->Bounds.X,e->Bounds.Y,(System::Int32)stringSize.Width,(System::Int32)stringSize.Height) );
   }

// Declare the MainMenu control.
internal System.Windows.Forms.MainMenu MainMenu1;

// Declare MenuItem2 as With-Events because it will be user drawn.
internal System.Windows.Forms.MenuItem MenuItem2;

private void InitializeMenu()
{

    // Create MenuItem1, which will be drawn by the operating system.
    MenuItem MenuItem1 = new MenuItem("Regular Menu Item");

    // Create MenuItem2.
    MenuItem2 = new MenuItem("Custom Menu Item");

    // Set OwnerDraw property to true. This requires handling the
    // DrawItem event for this menu item.
    MenuItem2.OwnerDraw = true;

    //Add the event-handler delegate to handle the DrawItem event.
    MenuItem2.DrawItem += new DrawItemEventHandler(DrawCustomMenuItem);
    
    // Add the items to the menu.
    MainMenu1 = new MainMenu(new MenuItem[]{MenuItem1, MenuItem2});																													  

    // Add the menu to the form.
    this.Menu = this.MainMenu1;
}

// Draw the custom menu item.
private void DrawCustomMenuItem(object sender, 
    DrawItemEventArgs e)
{

    // Cast the sender to MenuItem so you can access text property.
    MenuItem customItem = (MenuItem) sender;

    // Create a Brush and a Font to draw the MenuItem.
    System.Drawing.Brush aBrush = System.Drawing.Brushes.DarkMagenta;
    Font aFont = new Font("Garamond", 10, 
        FontStyle.Italic, GraphicsUnit.Point);

    // Get the size of the text to use later to draw an ellipse
    // around the item.
    SizeF stringSize = e.Graphics.MeasureString(
        customItem.Text, aFont);

    // Draw the item and then draw the ellipse.
    e.Graphics.DrawString(customItem.Text, aFont, 
        aBrush, e.Bounds.X, e.Bounds.Y);
    e.Graphics.DrawEllipse(new Pen(System.Drawing.Color.Black, 2),
        new Rectangle(e.Bounds.X, e.Bounds.Y, 
        (System.Int32)stringSize.Width,
        (System.Int32)stringSize.Height));
}

' Declare the MainMenu control.
Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu

' Declare MenuItem2 as With-Events because it will be user drawn.
Friend WithEvents MenuItem2 As System.Windows.Forms.MenuItem


Private Sub InitializeMenu()

    ' Create MenuItem1, which will be drawn by the operating system.
    Dim MenuItem1 As New MenuItem("Regular Menu Item")

    ' Create MenuItem2.
    MenuItem2 = New MenuItem("Custom Menu Item")

    ' Set OwnerDraw property to true. This requires handling the
    ' DrawItem event for this menu item.
    MenuItem2.OwnerDraw = True

    'Add the event-handler delegate to handle the DrawItem event.
    AddHandler MenuItem2.DrawItem, New DrawItemEventHandler(AddressOf DrawCustomMenuItem)

    ' Add the items to the menu.
    MainMenu1 = New MainMenu(New MenuItem() {MenuItem1, MenuItem2})

    ' Add the menu to the form.
    Me.Menu = Me.MainMenu1
End Sub

' Draw the custom menu item.
Private Sub DrawCustomMenuItem(ByVal sender As Object, ByVal e As _
        System.Windows.Forms.DrawItemEventArgs)

    ' Cast the sender to MenuItem so you can access text property.
    Dim customItem As MenuItem = CType(sender, MenuItem)

    ' Create a Brush and a Font to draw the MenuItem.
    Dim aBrush As System.Drawing.Brush = System.Drawing.Brushes.DarkMagenta
    Dim aFont As New Font("Garamond", 10, FontStyle.Italic, _
        GraphicsUnit.Point)

    ' Get the size of the text to use later to draw an ellipse
    ' around the item.
    Dim stringSize As SizeF = e.Graphics.MeasureString( _
        customItem.Text, aFont)

    ' Draw the item and then draw the ellipse.
    e.Graphics.DrawString(customItem.Text, aFont, _
        aBrush, e.Bounds.X, e.Bounds.Y)
    e.Graphics.DrawEllipse(New Pen(System.Drawing.Color.Black, 2), _
        New Rectangle(e.Bounds.X, e.Bounds.Y, CInt(stringSize.Width), _
        CInt(stringSize.Height)))
End Sub

注釈

DrawItemEventArgs デリゲートを作成する場合は、イベントを処理するメソッドを指定します。 イベント ハンドラーにイベントを関連付けるには、イベントにデリゲートのインスタンスを追加します。 イベント ハンドラーは、デリゲートを削除しない限り、イベントが発生するたびに呼び出されます。 イベント ハンドラー デリゲートの詳細については、「イベントの 処理と発生」を参照してください。

拡張メソッド

こちらもご覧ください

• DrawItemEventArgs
• ComboBox
• ListBox
• MenuItem
• TabControl