TreeView.EndUpdate TreeView.EndUpdate TreeView.EndUpdate TreeView.EndUpdate Method

Definition

Aktiviert das Neuzeichnen der Strukturansicht.Enables the redrawing of the tree view.

public:
 void EndUpdate();
public void EndUpdate ();
member this.EndUpdate : unit -> unit
Public Sub EndUpdate ()

Beispiele

Das folgende Codebeispiel zeigt die Kundeninformationen in einer TreeView Steuerelement.The following code example displays customer information in a TreeView control. Der Stammknoten zeigen die Namen der Kunden, und die untergeordneten Knoten angezeigt, die Bestellnummern, die einzelnen Kunden zugewiesen.The root tree nodes display customer names, and the child tree nodes display the order numbers assigned to each customer. In diesem Beispiel werden 1.000 Kunden mit jeweils 15 Aufträgen angezeigt.In this example, 1,000 customers are displayed with 15 orders each. Das Neuzeichnen der der TreeView unterdrückt wird, mithilfe der BeginUpdate und EndUpdate Methoden und einer Wartezeit Cursor angezeigt wird während der TreeView erstellt und zeichnet die TreeNode Objekte.The repainting of the TreeView is suppressed by using the BeginUpdate and EndUpdate methods, and a wait Cursor is displayed while the TreeView creates and paints the TreeNode objects. In diesem Beispiel benötigen Sie eine Customer -Objekt, das eine Auflistung von aufzunehmen kann Order Objekte.This example requires that you have a Customer object that can hold a collection of Order objects. Darüber hinaus müssen Sie eine Cursordatei haben, mit dem Namen MyWait.cur in das Anwendungsverzeichnis und die haben Sie eine Instanz von einem TreeView control für eine Form.It also requires that you have a cursor file that is named MyWait.cur in the application directory and that you have created an instance of a TreeView control on a Form.

// The basic Customer class.
ref class Customer: public System::Object
{
private:
   String^ custName;

protected:
   ArrayList^ custOrders;

public:
   Customer( String^ customername )
   {
      custName = "";
      custOrders = gcnew ArrayList;
      this->custName = customername;
   }


   property String^ CustomerName 
   {
      String^ get()
      {
         return this->custName;
      }

      void set( String^ value )
      {
         this->custName = value;
      }

   }

   property ArrayList^ CustomerOrders 
   {
      ArrayList^ get()
      {
         return this->custOrders;
      }

   }

};


// End Customer class
// The basic customer Order class.
ref class Order: public System::Object
{
private:
   String^ ordID;

public:
   Order( String^ orderid )
   {
      ordID = "";
      this->ordID = orderid;
   }


   property String^ OrderID 
   {
      String^ get()
      {
         return this->ordID;
      }

      void set( String^ value )
      {
         this->ordID = value;
      }

   }

};
// End Order class



void FillMyTreeView()
{
   // Add customers to the ArrayList of Customer objects.
   for ( int x = 0; x < 1000; x++ )
   {
      customerArray->Add( gcnew Customer( "Customer " + x ) );
   }
   
   // Add orders to each Customer object in the ArrayList.
   IEnumerator^ myEnum = customerArray->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Customer^ customer1 = safe_cast<Customer^>(myEnum->Current);
      for ( int y = 0; y < 15; y++ )
      {
         customer1->CustomerOrders->Add( gcnew Order( "Order " + y ) );
      }
   }

   // Display a wait cursor while the TreeNodes are being created.
   ::Cursor::Current = gcnew System::Windows::Forms::Cursor( "MyWait.cur" );
   
   // Suppress repainting the TreeView until all the objects have been created.
   treeView1->BeginUpdate();
   
   // Clear the TreeView each time the method is called.
   treeView1->Nodes->Clear();
   
   // Add a root TreeNode for each Customer object in the ArrayList.
   myEnum = customerArray->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Customer^ customer2 = safe_cast<Customer^>(myEnum->Current);
      treeView1->Nodes->Add( gcnew TreeNode( customer2->CustomerName ) );
      
      // Add a child treenode for each Order object in the current Customer object.
      IEnumerator^ myEnum = customer2->CustomerOrders->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         Order^ order1 = safe_cast<Order^>(myEnum->Current);
         treeView1->Nodes[ customerArray->IndexOf( customer2 ) ]->Nodes->Add( gcnew TreeNode( customer2->CustomerName + "." + order1->OrderID ) );
      }
   }
   
   // Reset the cursor to the default for all controls.
   ::Cursor::Current = Cursors::Default;
   
   // Begin repainting the TreeView.
   treeView1->EndUpdate();
}

// The basic Customer class.
public class Customer : System.Object
{
   private string custName = "";
   protected ArrayList custOrders = new ArrayList();

   public Customer(string customername)
   {
      this.custName = customername;
   }

   public string CustomerName
   {      
      get{return this.custName;}
      set{this.custName = value;}
   }

   public ArrayList CustomerOrders 
   {
      get{return this.custOrders;}
   }

} // End Customer class 


// The basic customer Order class.
public class Order : System.Object
{
   private string ordID = "";

   public Order(string orderid)
   {
      this.ordID = orderid;
   }

   public string OrderID
   {      
      get{return this.ordID;}
      set{this.ordID = value;}
   }

} // End Order class

// Create a new ArrayList to hold the Customer objects.
private ArrayList customerArray = new ArrayList(); 

private void FillMyTreeView()
{
   // Add customers to the ArrayList of Customer objects.
   for(int x=0; x<1000; x++)
   {
      customerArray.Add(new Customer("Customer" + x.ToString()));
   }

   // Add orders to each Customer object in the ArrayList.
   foreach(Customer customer1 in customerArray)
   {
      for(int y=0; y<15; y++)
      {
         customer1.CustomerOrders.Add(new Order("Order" + y.ToString()));    
      }
   }

   // Display a wait cursor while the TreeNodes are being created.
   Cursor.Current = new Cursor("MyWait.cur");
        
   // Suppress repainting the TreeView until all the objects have been created.
   treeView1.BeginUpdate();

   // Clear the TreeView each time the method is called.
   treeView1.Nodes.Clear();

   // Add a root TreeNode for each Customer object in the ArrayList.
   foreach(Customer customer2 in customerArray)
   {
      treeView1.Nodes.Add(new TreeNode(customer2.CustomerName));
          
      // Add a child treenode for each Order object in the current Customer object.
      foreach(Order order1 in customer2.CustomerOrders)
      {
         treeView1.Nodes[customerArray.IndexOf(customer2)].Nodes.Add(
           new TreeNode(customer2.CustomerName + "." + order1.OrderID));
      }
   }

   // Reset the cursor to the default for all controls.
   Cursor.Current = Cursors.Default;

   // Begin repainting the TreeView.
   treeView1.EndUpdate();
}
Public Class Customer
   Inherits [Object]
   Private custName As String = ""
   Friend custOrders As New ArrayList()

   Public Sub New(ByVal customername As String)
      Me.custName = customername
   End Sub

   Public Property CustomerName() As String
      Get
         Return Me.custName
      End Get
      Set(ByVal Value As String)
         Me.custName = Value
      End Set
   End Property

   Public ReadOnly Property CustomerOrders() As ArrayList
      Get
         Return Me.custOrders
      End Get
   End Property
End Class 'End Customer class


Public Class Order
   Inherits [Object]
   Private ordID As String

   Public Sub New(ByVal orderid As String)
      Me.ordID = orderid
   End Sub 'New

   Public Property OrderID() As String
      Get
         Return Me.ordID
      End Get
      Set(ByVal Value As String)
         Me.ordID = Value
      End Set
   End Property
End Class ' End Order class

' Create a new ArrayList to hold the Customer objects.
Private customerArray As New ArrayList()

Private Sub FillMyTreeView()
   ' Add customers to the ArrayList of Customer objects.
   Dim x As Integer
   For x = 0 To 999
      customerArray.Add(New Customer("Customer" + x.ToString()))
   Next x

   ' Add orders to each Customer object in the ArrayList.
   Dim customer1 As Customer
   For Each customer1 In customerArray
      Dim y As Integer
      For y = 0 To 14
         customer1.CustomerOrders.Add(New Order("Order" + y.ToString()))
      Next y
   Next customer1

   ' Display a wait cursor while the TreeNodes are being created.
   Cursor.Current = New Cursor("MyWait.cur")

   ' Suppress repainting the TreeView until all the objects have been created.
   treeView1.BeginUpdate()

   ' Clear the TreeView each time the method is called.
   treeView1.Nodes.Clear()

   ' Add a root TreeNode for each Customer object in the ArrayList.
   Dim customer2 As Customer
   For Each customer2 In customerArray
      treeView1.Nodes.Add(New TreeNode(customer2.CustomerName))

      ' Add a child TreeNode for each Order object in the current Customer object.
      Dim order1 As Order
      For Each order1 In customer2.CustomerOrders
         treeView1.Nodes(customerArray.IndexOf(customer2)).Nodes.Add( _
    New TreeNode(customer2.CustomerName + "." + order1.OrderID))
      Next order1
   Next customer2

   ' Reset the cursor to the default for all controls.
   Cursor.Current = System.Windows.Forms.Cursors.Default

   ' Begin repainting the TreeView.
   treeView1.EndUpdate()
End Sub 'FillMyTreeView

Hinweise

Um die Leistung zu gewährleisten, während Elemente einzeln nacheinander zu hinzugefügt werden die TreeView, rufen Sie die BeginUpdate Methode.To maintain performance while items are added one at a time to the TreeView, call the BeginUpdate method. Die BeginUpdate Methode verhindert, dass das Steuerelement zeichnen, bis die EndUpdate Methode wird aufgerufen.The BeginUpdate method prevents the control from painting until the EndUpdate method is called.

Die bevorzugte Methode für die Elemente hinzugefügt werden einem Strukturansicht-Steuerelement ist die Verwendung der AddRange Methode, um ein Array von Strukturelemente für Knoten einer Strukturansicht hinzuzufügen.The preferred way to add items to a tree view control is to use the AddRange method to add an array of tree node items to a tree view. Allerdings verwenden, wenn Sie Elemente gleichzeitig hinzufügen möchten, die BeginUpdate Methode, um zu verhindern, dass die TreeView Steuerelement nicht während der Hinzufügevorgänge gezeichnet.However, if you want to add items one at a time, use the BeginUpdate method to prevent the TreeView control from painting during the add operations. Um das Steuerelement zum Zeichnen fortsetzen ermöglichen, rufen Sie die EndUpdate Methode, wenn die Strukturknoten der Strukturansicht hinzugefügt wurden.To allow control the control to resume painting, call the EndUpdate method when all the tree nodes have been added to the tree view.

Gilt für:

Siehe auch