DataGrid.SortCommand Event

 

Occurs when a column is sorted.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

Public Event SortCommand As DataGridSortCommandEventHandler

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.

For more information about handling events, see NIB: 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="VB" %>
<%@ 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">
    Function CreateDataSource() As ICollection
        ' Create a Random object to mix up the order 
        ' of items in the sample data.
        Dim randNum As Random = New Random()

        ' Create sample data for the DataGrid control.
        Dim dt As DataTable = New DataTable()

        ' Define the columns of the table.
        dt.Columns.Add( _
            New DataColumn("IntegerValue", GetType(Int32)))
        dt.Columns.Add( _
            New DataColumn("StringValue", GetType(String)))
        dt.Columns.Add( _
            New DataColumn("CurrencyValue", GetType(Double)))

        ' Populate the table with sample values.
        Dim i As Integer
        For i = 0 To 8
            Dim dr As DataRow = 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)
        Next

        ' Persist the data source between posts to 
        ' the server, in the session state.  
        Session("Source") = dt

        Dim dv As DataView = New DataView(dt)
        Return dv
    End Function

    Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        ' Load sample data when the page is first loaded.
        If Not IsPostBack Then
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
        End If
    End Sub

    Sub Sort_Grid(ByVal sender As Object, _
        ByVal e As DataGridSortCommandEventArgs)

        ' Retrieve the data source from session state.
        Dim dt As DataTable = _
            CType(Session("Source"), DataTable)

        ' Create a DataView from the DataTable.
        Dim dv As DataView = 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()
    End Sub

    Sub Check_Change(ByVal sender As Object, _
        ByVal e As EventArgs)
        ' 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 data source from session state.
        Dim dt As DataTable = _
            CType(Session("Source"), DataTable)

        ' Create a DataView from the DataTable.
        Dim dv As DataView = New DataView(dt)

        ' Rebind the data source.
        ItemsGrid.DataSource = dv
        ItemsGrid.DataBind()
    End Sub
</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="VB" 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">

      Function CreateDataSource() As ICollection 

         ' Create a Random object to mix up the order of items in the sample data.
         Dim Rand_Num As Random = New Random()

         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow

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

         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 To 8 

            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)

         Next i

         ' To persist the data source between posts to the server, store it
         ' in session state.  
         Session("Source") = dt

         Dim dv As DataView = New DataView(dt)

         Return dv

      End Function

      Sub Page_Load(sender As Object, e As EventArgs) 

         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 

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

         End If

         ' Manually register the event-handling method for the PageIndexChanged  
         ' event of the DataGrid control.
         AddHandler ItemsGrid.SortCommand, AddressOf Sort_Grid

      End Sub

      Sub Sort_Grid(sender As Object, e As DataGridSortCommandEventArgs) 

         ' Retrieve the data source from session state.
         Dim dt As DataTable = CType(Session("Source"), DataTable)

         ' Create a DataView from the DataTable.
         Dim dv As DataView = 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()

      End Sub

      Sub Check_Change(sender As Object, e As EventArgs)

         ' Allow or prevent sorting depending on the user's selection.
         If AllowSortingCheckBox.Checked Then

            ItemsGrid.AllowSorting = True

         Else

            ItemsGrid.AllowSorting = False

         End If

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

         ' Retrieve the data source from session state.
         Dim dt As DataTable = CType(Session("Source"), DataTable)

         ' Create a DataView from the DataTable.
         Dim dv As DataView = New DataView(dt)

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

      End Sub

   </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
Available since 1.1
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