TreeNode 类

项目
08/17/2007

表示 TreeView 的节点。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
<SerializableAttribute> _
Public Class TreeNode
    Inherits MarshalByRefObject
    Implements ICloneable, ISerializable
用法
Dim instance As TreeNode

[SerializableAttribute] 
public class TreeNode : MarshalByRefObject, ICloneable, ISerializable

[SerializableAttribute] 
public ref class TreeNode : public MarshalByRefObject, ICloneable, ISerializable

/** @attribute SerializableAttribute() */ 
public class TreeNode extends MarshalByRefObject implements ICloneable, ISerializable

SerializableAttribute 
public class TreeNode extends MarshalByRefObject implements ICloneable, ISerializable

备注

Nodes 集合包含所有分配给当前 TreeNode 的子 TreeNode 对象。您可以添加、移除或克隆 TreeNode；当这样做时，将添加、删除或克隆所有子树节点。每个 TreeNode 都可以包含其他 TreeNode 对象的集合。这种情况下，当您循环访问集合时，将很难确定自己是否在 TreeView 中。要确定您在树结构中的位置，可使用 FullPath 属性。FullPath 字符串可以使用 PathSeparator 字符串值来进行分析，以确定 TreeNode 标签的起始和终止位置。

TreeNode 标签通过显式设置 Text 属性来进行设置。另一种替代方法是使用 TreeNode 构造函数之一创建树节点，并使其具有表示 Text 属性的字符串参数。如果显示标签，则标签显示在 TreeNode 图像的旁边。

要显示树节点旁边的图像，可将 ImageList 分配给父 TreeView 控件的 ImageList 属性，然后通过引用它在 ImageList 属性中的索引值来分配 Image。将 ImageIndex 属性设置为当 TreeNode 处于未选定状态时要显示的 Image 的索引值。同样，将 SelectedImageIndex 属性设置为当 TreeNode 已选定时要显示的 Image 的索引值。

若要选择特定的树节点并循环访问 Nodes 集合，可以使用以下属性值来实现：FirstNode、LastNode、NextNode、PrevNode、NextVisibleNode、PrevVisibleNode。将上述属性之一返回的 TreeNode 分配给 TreeView.SelectedNode 属性，以便选择 TreeView 控件中的该树节点。

树节点可以展开，以显示下一级子树节点。用户可以在 TreeNode 旁显示加号 (+) 按钮时通过单击加号 (+) 按钮来展开 TreeNode，或者可以通过调用 Expand 方法来展开 TreeNode。若要展开 Nodes 集合中的所有子树节点级别，请调用 ExpandAll 方法。若要折叠子 TreeNode 级别，可以调用 Collapse 方法，也可以在 TreeNode 旁显示减号 (-) 按钮时按减号 (-) 按钮。还可以通过调用 Toggle 方法使 TreeNode 在展开和折叠状态之间切换。

树节点可以选择性地显示复选框。若要显示复选框，请将 TreeView 的 CheckBoxes 属性设置为 true。对于处于选中状态的树节点，Checked 属性设置为 true。

给继承者的说明 由于 TreeNode 类实现 ISerializable 接口，因此派生类要可序列化也必须实现此接口以及自定义序列化中所描述的特殊构造函数。

示例

下面的代码示例在 TreeView 控件中显示客户信息。根树节点显示客户名称，子树节点显示分配给每个客户的订单编号。在本示例中，显示 1,000 个客户，每个客户有 15 个订单。使用 BeginUpdate 方法和 EndUpdate 方法可取消重新绘制 TreeView，在 TreeView 创建和绘制 TreeNode 对象时，显示等待 Cursor。本示例要求有一个 Customer 对象，它可存放 Order 对象的集合。本示例还要求您在 Form 上创建了 TreeView 控件的一个实例。

' 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

// 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();
}

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.
   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();
}

// 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"
            + ((Int32)x).ToString()));
    }
    // Add orders to each Customer object in the ArrayList.
    for (int iCtr = 0; iCtr < customerArray.get_Count(); iCtr++) {
        Customer customer1 = (Customer)customerArray.get_Item(iCtr);
        for (int y = 0; y < 15; y++) {
            customer1.get_CustomerOrders().Add(new Order("Order"
                + ((Int32)y).ToString()));
        }
    }
    // Display a wait cursor while the TreeNodes are being created.
    get_Cursor().set_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.get_Nodes().Clear();
    // Add a root TreeNode for each Customer object in the ArrayList.
    for (int iCtr1 = 0; iCtr1 < customerArray.get_Count(); iCtr1++) {
        Customer customer2 = (Customer)customerArray.get_Item(iCtr1);
        treeView1.get_Nodes().Add(new TreeNode(customer2.get_CustomerName()));
        // Add a child treenode for each Order object in the current
        // Customer object.
        for (int iCtr2 = 0; iCtr2 < customer2.get_CustomerOrders().
            get_Count(); iCtr2++) {
            Order order1 = (Order)customer2.get_CustomerOrders().
                get_Item(iCtr2);
            treeView1.get_Nodes().
                get_Item(customerArray.IndexOf(customer2)).get_Nodes().
                Add(new TreeNode(customer2.get_CustomerName() + "."
                + order1.get_OrderID()));
        }
    }
    // Reset the cursor to the default for all controls.
    get_Cursor().set_Current(Cursors.get_Default());
    // Begin repainting the TreeView.
    treeView1.EndUpdate();
} //FillMyTreeView

继承层次结构

System.Object
   System.MarshalByRefObject
    System.Windows.Forms.TreeNode
       System.ComponentModel.Design.ObjectSelectorEditor.SelectorNode

线程安全

此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

TreeNode 类

语法

备注

示例

继承层次结构

线程安全

平台

版本信息

.NET Framework

.NET Compact Framework

请参见

参考

其他资源

其他资源