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DataGrid.OnSortCommand Method

Raises the SortCommand event. This allows you to provide a custom handler for the event.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)
protected virtual void OnSortCommand(
	DataGridSortCommandEventArgs e
)

Use the OnSortCommand method to provide a custom handler for the SortCommand event.

The SortCommand event is raised when a column is sorted.

A typical handler for the SortCommand event sorts the list, and then rebinds the data to the DataGrid control.

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

Notes to Inheritors

When overriding OnSortCommand in a derived class, be sure to call the base class's OnSortCommand method.

For more information about handling events, see Consuming Events.

The following code example demonstrates how to specify and code a handler for the SortCommand event to sort a DataGrid control.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

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

<script runat="server">
    ICollection CreateDataSource()
    {
        // Create a Random object to mix up the 
        // order of items in the sample data.
        Random randNum = new Random();

        // Create sample data for the DataGrid control.
        DataTable dt = new DataTable();

        // Define the columns of the table.
        dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
        dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
        dt.Columns.Add(new DataColumn("CurrencyValue", typeof(Double)));

        // Populate the table with sample values.
        for (int i = 0; i <= 8; i++)
        {
            DataRow dr = dt.NewRow();
            dr[0] = i;
            dr[1] = "Item " + randNum.Next(1, 15).ToString();
            dr[2] = 1.23 * randNum.Next(1, 15);
            dt.Rows.Add(dr);
        }

        // To persist the data source between posts to the server,
        // store it in session state.  
        Session["Source"] = dt;
        DataView dv = new DataView(dt);
        return dv;
    }

    void Page_Load(Object sender, EventArgs e)
    {
        // Load sample data only once, when the page is first loaded.
        if (!IsPostBack)
        {
            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();
        }
    }

    void Sort_Grid(Object sender, DataGridSortCommandEventArgs e)
    {
        // Retrieve the data source from session state.
        DataTable dt = (DataTable)Session["Source"];

        // Create a DataView from the DataTable.
        DataView dv = new DataView(dt);

        // The DataView provides an easy way to sort. Simply set the
        // Sort property with the name of the field to sort by.
        dv.Sort = e.SortExpression;

        // Rebind the data source and specify that it should be sorted
        // by the field specified in the SortExpression property.
        ItemsGrid.DataSource = dv;
        ItemsGrid.DataBind();
    }

    void Check_Change(Object sender, EventArgs e)
    {
        // Allow or prevent sorting depending on the user's selection.
        ItemsGrid.AllowSorting = AllowSortingCheckBox.Checked;

        // After changing the property, rebind the data to
        // refresh the DataGrid control.

        // Retrieve the data source from session state.
        DataTable dt = (DataTable)Session["Source"];

        // Create a DataView from the DataTable.
        DataView dv = new DataView(dt);

        // Rebind the data source.
        ItemsGrid.DataSource = dv;
        ItemsGrid.DataBind();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>
        ExtractTemplateRows Example
    </title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
      <h3>DataGrid AllowSorting Example</h3>

      <p>Select whether to allow sorting in the DataGrid control.<br />
      <asp:CheckBox id="AllowSortingCheckBox"
           Text="Allow sorting"
           AutoPostBack="True"
           Checked="True"
           OnCheckedChanged="Check_Change"
           runat="server"/></p>
      <hr />

      <b>Product List</b>
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           OnSortCommand="Sort_Grid"
           UseAccessibleHeader="true"
           AutoGenerateColumns="False"
           AllowSorting="True"
           runat="server">

         <HeaderStyle BackColor="#00aaaa" />
         <Columns>
            <asp:BoundColumn DataField="IntegerValue" 
                 SortExpression="IntegerValue"
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 SortExpression="StringValue" 
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue" 
                 HeaderText="Price"
                 SortExpression="CurrencyValue"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>
            </asp:BoundColumn>
         </Columns> 
      </asp:DataGrid>

   </div>
   </form>
</body>
</html>

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script runat="server">

      ICollection CreateDataSource()
      {

         // Create a Random object to mix up the order of items in the sample data.
         Random Rand_Num = new Random();

         // Create sample data for the DataGrid control.
         DataTable dt = new DataTable();
         DataRow dr;

         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(Double)));

         // Populate the table with sample values.
         for (int i=0; i<=8; i++) 
         {

            dr = dt.NewRow();

            dr[0] = i;
            dr[1] = "Item " + Rand_Num.Next(1, 15).ToString();
            dr[2] = 1.23 * Rand_Num.Next(1, 15);

            dt.Rows.Add(dr);

         }

         // To persist the data source between posts to the server, store it
         // in session state.  
         Session["Source"] = dt;

         DataView dv = new DataView(dt);

         return dv;

      }

      void Page_Load(Object sender, EventArgs e)
      { 

         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack)
         { 

            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();

         }

         // Manually register the event-handling method for the PageIndexChanged  
         // event of the DataGrid control.
         ItemsGrid.SortCommand += new DataGridSortCommandEventHandler(this.Sort_Grid);

      }

      void Sort_Grid(Object sender, DataGridSortCommandEventArgs e)
      { 

         // Retrieve the data source from session state.
         DataTable dt = (DataTable)Session["Source"];

         // Create a DataView from the DataTable.
         DataView dv = new DataView(dt);

         // The DataView provides an easy way to sort. Simply set the Sort property with
         // the name of the field to sort by.
         dv.Sort = e.SortExpression;

         // Re-bind the data source and specify that it should be sorted
         // by the field specified in the SortExpression property.
         ItemsGrid.DataSource = dv;
         ItemsGrid.DataBind();

      }

      void Check_Change(Object sender, EventArgs e)
      {

         // Allow or prevent sorting depending on the user's selection.
         if (AllowSortingCheckBox.Checked)
         {

            ItemsGrid.AllowSorting = true;

         }
         else
         {

            ItemsGrid.AllowSorting = false;

         }

         // After changing the property, re-bind the data to
         // refresh the DataGrid control.

         // Retrieve the data source from session state.
         DataTable dt = (DataTable)Session["Source"];

         // Create a DataView from the DataTable.
         DataView dv = new DataView(dt);

         // Re-bind the data source.
         ItemsGrid.DataSource = dv;
         ItemsGrid.DataBind();

      }

   </script>

<head runat="server">
    <title>DataGrid SortCommand Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>DataGrid SortCommand Example</h3>

      Select whether to allow sorting in the DataGrid control.

      <br /><br />

      <b>Product List</b>

      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           AutoGenerateColumns="False"
           AllowSorting="True"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue" 
                 SortExpression="IntegerValue"
                 HeaderText="Item"/>

            <asp:BoundColumn DataField="StringValue"
                 SortExpression="StringValue" 
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue" 
                 HeaderText="Price"
                 SortExpression="CurrencyValue"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

         </Columns> 

      </asp:DataGrid>

      <hr />

      <asp:CheckBox id="AllowSortingCheckBox"
           Text="Allow sorting"
           AutoPostBack="True"
           Checked="True"
           OnCheckedChanged="Check_Change"
           runat="server"/>

   </form>

</body>
</html>

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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