แก้ไข

แชร์ผ่าน


Menu.MenuItemCollection.Contains(MenuItem) Method

Definition

Determines if the specified MenuItem is a member of the collection.

public:
 bool Contains(System::Windows::Forms::MenuItem ^ value);
public bool Contains (System.Windows.Forms.MenuItem value);
member this.Contains : System.Windows.Forms.MenuItem -> bool
Public Function Contains (value As MenuItem) As Boolean

Parameters

value
MenuItem

The MenuItem to locate in the collection.

Returns

true if the MenuItem is a member of the collection; otherwise, false.

Examples

In this example, you create a main menu, myMainMenu, with two MenuItem objects, File and Edit. The File menu has three submenu items, New, Open, and Exit. By using the Contains method, you check to see if the File menu collection contains the item Open. If the item exists, you display the result in a text box. This program requires that you have already created a Form named Form1.

public:
   void InitializeMenu()
   {
      // Create the MainMenu object.
      MainMenu^ myMainMenu = gcnew MainMenu;
      
      // Create the MenuItem objects.
      MenuItem^ fileMenu = gcnew MenuItem( "&File" );
      MenuItem^ editMenu = gcnew MenuItem( "&Edit" );
      MenuItem^ newFile = gcnew MenuItem( "&New" );
      MenuItem^ openFile = gcnew MenuItem( "&Open" );
      MenuItem^ exitProgram = gcnew MenuItem( "E&xit" );
      
      // Add the MenuItem objects to myMainMenu.
      myMainMenu->MenuItems->Add( fileMenu );
      myMainMenu->MenuItems->Add( editMenu );
      
      // Add three submenus to the File menu.
      fileMenu->MenuItems->Add( newFile );
      fileMenu->MenuItems->Add( openFile );
      fileMenu->MenuItems->Add( exitProgram );
      
      // Assign myMainMenu to the form.
      Menu = myMainMenu;
      
      // Check that the File menu contains the Open menu item.
      if ( fileMenu->MenuItems->Contains( openFile ) )
      {
         MessageBox::Show( "The File menu contains 'Open' " + fileMenu->Text );
      }
   }
public void InitializeMenu()
{
    // Create the MainMenu object.
    MainMenu myMainMenu = new MainMenu();
    
    // Create the MenuItem objects.
    MenuItem fileMenu = new MenuItem("&File");
    MenuItem editMenu = new MenuItem("&Edit");
    MenuItem newFile = new MenuItem("&New");
    MenuItem openFile = new MenuItem("&Open");
    MenuItem exitProgram = new MenuItem("E&xit");
    
    // Add the MenuItem objects to myMainMenu.
    myMainMenu.MenuItems.Add(fileMenu);
    myMainMenu.MenuItems.Add(editMenu);
    
    // Add three submenus to the File menu.
    fileMenu.MenuItems.Add(newFile);
    fileMenu.MenuItems.Add(openFile);
    fileMenu.MenuItems.Add(exitProgram);
    
    // Assign myMainMenu to the form.
    Menu = myMainMenu;
    
    // Check that the File menu contains the Open menu item.
    if (fileMenu.MenuItems.Contains(openFile))
    {
        MessageBox.Show("The File menu contains 'Open' ", fileMenu.Text);
    }
}
Public Sub InitializeMenu()
   ' Create the MainMenu object.
   Dim myMainMenu As New MainMenu()
   
   ' Create the MenuItem objects.
   Dim fileMenu As New MenuItem("&File")
   Dim editMenu As New MenuItem("&Edit")
   Dim newFile As New MenuItem("&New")
   Dim openFile As New MenuItem("&Open")
   Dim exitProgram As New MenuItem("E&xit")
   
   ' Add the MenuItem objects to myMainMenu.
   myMainMenu.MenuItems.Add(fileMenu)
   myMainMenu.MenuItems.Add(editMenu)
   
   ' Add three submenus to the File menu.
   fileMenu.MenuItems.Add(newFile)
   fileMenu.MenuItems.Add(openFile)
   fileMenu.MenuItems.Add(exitProgram)
   
   ' Assign myMainMenu to the form.
   Menu = myMainMenu
   
   ' Check that the File menu contains the Open menu item.
   If fileMenu.MenuItems.Contains(openFile) Then
      MessageBox.Show("The File menu contains 'Open' ", fileMenu.Text)
   End If
End Sub 
'InitializeMenu

Remarks

This method enables you to determine whether a MenuItem is member of the collection before attempting to perform operations on the MenuItem. You can use this method to confirm that a MenuItem has been added to or is still a member of the collection.

Applies to