使用英语阅读

通过

GridViewSortEventHandler 委托

  • 参考

定义

命名空间:
System.Web.UI.WebControls
程序集:
System.Web.dll

表示处理 Sorting 控件的 GridView 事件的方法。

C# 
public delegate void GridViewSortEventHandler(object sender, GridViewSortEventArgs e);

参数

sender
Object

事件源。

e
GridViewSortEventArgs

包含事件数据的 GridViewSortEventArgs 对象。

示例

下面的示例演示如何以编程方式向 控件的 GridView 事件添加GridViewSortEventHandler委托Sorting。

ASP.NET (C#) 

<%@ 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)
    {
        
        // Create a new GridView object.
        GridView authorGridView = new GridView();
         
        // Set the GridView object's properties.
        authorGridView.ID = "AuthorGridView";
        authorGridView.DataSourceID = "AuthorsSqlDataSource"; 
        authorGridView.AutoGenerateColumns = true;
        authorGridView.AllowSorting = true;
        
        // Programmatically register the event-handling methods.
        authorGridView.Sorting += new GridViewSortEventHandler(this.AuthorsGridView_Sorting);
        
        // Add the GridView object to the Controls collection
        // of the PlaceHolder control.
        GridViewPlaceHolder.Controls.Add(authorGridView);
        
    }
    
    void AuthorsGridView_Sorting(Object sender, GridViewSortEventArgs e)
    {
    
        // Cancel the sorting operation if the user attempts to sort
        // the Contract column.
        if(e.SortExpression == "contract")
        {
            e.Cancel = true;
            Message.Text = "You cannot sort the Contract column.";
        }
        else
        {
            // Clear the message label.
            Message.Text = "";
        }
    
    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>GridViewSortEventHandler Example</title>
</head>
<body>
        <form id="form1" runat="server">
        
            <h3>GridViewSortEventHandler Example</h3>
            
            <asp:label id="Message"
                forecolor="Red"
                runat="server"/>
                
            <br/>
            
            <asp:placeholder id="GridViewPlaceHolder"
                runat="Server"/>
            
            <!-- This example uses Microsoft SQL Server and connects -->
            <!-- to the Pubs sample database.                         -->
            <asp:sqldatasource id="AuthorsSqlDataSource"  
                selectcommand="SELECT [au_id], [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
                updatecommand="UPDATE authors SET au_lname=@au_lname, au_fname=@au_fname, address=@address, city=@city, state=@state, zip=@zip, contract=@contract WHERE (authors.au_id = @au_id)"
                connectionstring="server=localhost;database=pubs;integrated security=SSPI"
                runat="server">
            </asp:sqldatasource>
            
        </form>
    </body>
</html>

以下示例演示如何以声明方式向 控件的 GridView 事件添加GridViewSortEventHandler委托Sorting。

ASP.NET (C#) 

<%@ 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 CustomersGridView_Sorting(Object sender, GridViewSortEventArgs e)
  {
    // Cancel the sorting operation if the user attempts
    // to sort by address.
    if (e.SortExpression == "Address")
    {
      e.Cancel = true;
      Message.Text = "You cannot sort by address.";
      SortInformationLabel.Text = "";
    }
    else
    {
      Message.Text = "";
    }
  }

  void CustomersGridView_Sorted(Object sender, EventArgs e)
  {
    // Display the sort expression and sort direction.
    SortInformationLabel.Text = "Sorting by " +
      CustomersGridView.SortExpression.ToString() +
      " in " + CustomersGridView.SortDirection.ToString() +
      " order.";
  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView Sorting Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView Sorting Example</h3>

      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
        
      <br/>
        
      <asp:label id="SortInformationLabel"
        forecolor="Navy"
        runat="server"/>
                
      <br/>  

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        allowpaging="true"
        emptydatatext="No data available." 
        allowsorting="true"
        onsorting="CustomersGridView_Sorting"
        onsorted="CustomersGridView_Sorted"  
        runat="server">
                
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
        
    </form>
  </body>
</html>

注解

当 Sorting 单击用于对列进行排序的超链接时，但在控件处理排序操作之前 GridView ，将引发 该事件。 这允许你提供一个事件处理方法，该方法执行自定义例程，例如，每当发生此事件时取消排序操作。

创建 GridViewSortEventHandler 委托时，需要标识将处理该事件的方法。 若要将事件与事件处理程序关联，请将该委托的一个实例添加到事件中。 除非移除了该委托，否则每当发生该事件时就会调用事件处理程序。 有关事件处理程序委托的详细信息，请参阅 处理和引发事件。

扩展方法

GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。

适用于

产品 版本
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

另请参阅