Partilhar via

TreeNode.Collapse Método

  • Referência

Definição

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Recolhe o nó de árvore atual.

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

Exemplos

O exemplo de código a seguir demonstra como usar o Collapse método para recolher programaticamente um nó no TreeView controle. Para que este exemplo funcione corretamente, você deve copiar os dados XML de exemplo abaixo para um arquivo chamado Book.xml.


<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void Data_Bound(Object sender, TreeNodeEventArgs e)
  {

    // Determine the depth of a node as it is bound to data.
    // If the depth is 1, expand the node.
    if(e.Node.Depth == 1)
    {

      // Expand the node using the Expand method.
      e.Node.Expand();

    }
    else
    {

      // Collapse the node using the Collapse method.
      e.Node.Collapse();

    }

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNode Expand and Collapse Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNode Expand and Collapse Example</h3>
      
      <h5>Expand the root node. Notice that the child nodes are already expanded.</h5>
    
      <asp:TreeView id="BookTreeView" 
         DataSourceID="BookXmlDataSource"
         OnTreeNodeDataBound="Data_Bound"
         runat="server">
         
        <DataBindings>
          <asp:TreeNodeBinding DataMember="Book" TextField="Title"/>
          <asp:TreeNodeBinding DataMember="Chapter" TextField="Heading"/>
          <asp:TreeNodeBinding DataMember="Section" TextField="Heading"/>
        </DataBindings>
         
      </asp:TreeView>
      
      <asp:XmlDataSource id="BookXmlDataSource"  
         DataFile="Book.xml"
         runat="server">
      </asp:XmlDataSource>
    
    </form>
  </body>
</html>


<%@ Page Language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub Data_Bound(ByVal sender As Object, ByVal e As TreeNodeEventArgs)

    ' Determine the depth of a node as it is bound to data.
    ' If the depth is 1, expand the node.
    If e.Node.Depth = 1 Then

      ' Expand the node using the Expand method.
      e.Node.Expand()

    Else

      ' Collapse the node using the Collapse method.
      e.Node.Collapse()

    End If

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNode Expand and Collapse Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNode Expand and Collapse Example</h3>
      
      <h5>Expand the root node. Notice that the child nodes are already expanded.</h5>
    
      <asp:TreeView id="BookTreeView" 
         DataSourceID="BookXmlDataSource"
         OnTreeNodeDataBound="Data_Bound"
         runat="server">
         
        <DataBindings>
          <asp:TreeNodeBinding DataMember="Book" TextField="Title"/>
          <asp:TreeNodeBinding DataMember="Chapter" TextField="Heading"/>
          <asp:TreeNodeBinding DataMember="Section" TextField="Heading"/>
        </DataBindings>
         
      </asp:TreeView>
      
      <asp:XmlDataSource id="BookXmlDataSource"  
         DataFile="Book.xml"
         runat="server">
      </asp:XmlDataSource>
    
    </form>
  </body>
</html>

O código a seguir é dados XML de exemplo para o exemplo anterior.

<Book Title="Book Title">  
    <Chapter Heading="Chapter 1">  
        <Section Heading="Section 1">  
        </Section>  
        <Section Heading="Section 2">  
        </Section>  
    </Chapter>  
    <Chapter Heading="Chapter 2">  
        <Section Heading="Section 1">  
        </Section>  
    </Chapter>  
</Book>

Comentários

Use o Collapse método para recolher convenientemente o nó atual.

Observação

Como alternativa, você também pode definir a Expanded propriedade como false.

Para recolher o nó atual e todos os seus nós filho, considere usar o CollapseAll método.

CollapseAll recolherá todos os nós na árvore inteira.

Aplica-se a

Confira também