TreeNodeBindingCollection.RemoveAt(Int32) Method

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Removes the TreeNodeBinding object at the specified index location from the TreeNodeBindingCollection object.

public:
 void RemoveAt(int index);

public void RemoveAt (int index);

member this.RemoveAt : int -> unit

Public Sub RemoveAt (index As Integer)

Parameters

index: Int32

The zero-based index location of the TreeNodeBinding to remove.

Examples

The following code example demonstrates how to use the RemoveAt method to remove a TreeNodeBinding object programmatically from a TreeNodeBindingCollection object. For this example to work correctly, you must copy the XML data that is located at the end of this section to a file called 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 Page_Load(Object sender, EventArgs e)
  {

    // Use the RemoveAt method to remove the TreeNodeBinding object 
    // for the third-level nodes (index 2).
    BookTreeView.DataBindings.RemoveAt(2);

    // Create a new TreeNodeBinding object and set its properties.
    TreeNodeBinding newBinding = new TreeNodeBinding();
    newBinding.DataMember = "Section";
    newBinding.TextField = "Subject";

    // Use the Insert method to insert the TreeNodeBinding object 
    // into the DaaBindings collection at index 2.
    BookTreeView.DataBindings.Insert(2, newBinding);

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>TreeNodeBindingCollection Insert and RemoveAt Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>TreeNodeBindingCollection Insert and RemoveAt Example</h3>
    
      <asp:TreeView id="BookTreeView" 
        DataSourceID="BookXmlDataSource"
        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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)

        ' Use the RemoveAt method to remove the TreeNodeBinding object
        ' for the third-level nodes (index 2).
        BookTreeView.DataBindings.RemoveAt(2)

        ' Create a new TreeNodeBinding object and set its properties.
        Dim newBinding As TreeNodeBinding = New TreeNodeBinding
        newBinding.DataMember = "Section"
        newBinding.TextField = "Subject"

        ' Use the Insert method to insert the TreeNodeBinding object to
        ' the DataBindings collection at index 2.
        BookTreeView.DataBindings.Insert(2, newBinding)

    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>TreeNodeBindingCollection Insert and RemoveAt Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>TreeNodeBindingCollection Insert and RemoveAt Example</h3>
        
            <asp:TreeView id="BookTreeView" 
                DataSourceID="BookXmlDataSource"
                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>

The following is the XML data for the preceding code example.

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

Remarks

Use the RemoveAt method to remove the TreeNodeBinding object located at index from a TreeNodeBindingCollection object. All items that follow that node are then moved up to fill the vacant position. The indexes of the moved items are also updated.

As an alternative, you can remove a specific TreeNodeBinding object by using the Remove method. You can also remove every node in the collection by using the Clear method.

Applies to

Freigeben über