ObjectDataSource.SortParameterName Property
Definition
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.
Gets or sets the name of the business object that the SelectMethod parameter used to specify a sort expression for data source sorting support.
public:
property System::String ^ SortParameterName { System::String ^ get(); void set(System::String ^ value); };public string SortParameterName { get; set; }member this.SortParameterName : string with get, setPublic Property SortParameterName As StringProperty Value
The name of the method parameter used to indicate the parameter which is used to sort the data. The default is an empty string.
Examples
This section contains two code examples. The first code example demonstrates how to implement a type that supports sorting. The second code example demonstrates how to implement a sort expression.
The following code example demonstrates how to implement a type that supports sorting. The SelectMethod of the SortingData class takes a parameter, sortExpression. The string that is passed to SelectMethod is used for the Sort property of the DataView object that is returned by SelectMethod.
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
namespace Samples.AspNet.CS
{
public class SortingData
{
public SortingData()
{
}
private static DataTable table;
private DataTable CreateData()
{
table = new DataTable();
table.Columns.Add("Name", typeof(string));
table.Columns.Add("Number", typeof(int));
table.Rows.Add(new object[] { "one", 1 });
table.Rows.Add(new object[] { "two", 2 });
table.Rows.Add(new object[] { "three", 3 });
table.Rows.Add(new object[] { "four", 4 });
return table;
}
public DataView SelectMethod(string sortExpression)
{
table ??= CreateData();
DataView dv = new DataView(table);
dv.Sort = sortExpression;
return dv;
}
}
}
Imports System.Data
Imports System.Configuration
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.HtmlControls
Namespace Samples.AspNet.VB
Public Class SortingData
Public Sub New()
End Sub
Private Shared table As DataTable
Private Function CreateData() As DataTable
table = New DataTable()
table.Columns.Add("Name", GetType(String))
table.Columns.Add("Number", GetType(Integer))
table.Rows.Add(New Object() {"one", 1})
table.Rows.Add(New Object() {"two", 2})
table.Rows.Add(New Object() {"three", 3})
table.Rows.Add(New Object() {"four", 4})
Return table
End Function
Public Function SelectMethod(ByVal sortExpression As String) As DataView
If table Is Nothing Then
table = CreateData()
End If
Dim dv As New DataView(table)
dv.Sort = sortExpression
Return dv
End Function
End Class
End Namespace
The following code example demonstrates how to implement a sort expression. The code in the Web page creates an instance of the ObjectDataSource control. The TypeName property is set to SortingData and the SortParameterName property is set to sortExpression. The AllowSorting property of the GridView control is set to true. When the user clicks the Sort button, the field name, Name or Number, is passed to SelectMethod in the sort parameter.
<%--<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS" Assembly="Samples.AspNet.CS" %>
--%><%@ 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">
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="GridView1"
runat="server"
DataSourceID="ObjectDataSource1"
AllowSorting="True">
</asp:GridView>
<asp:ObjectDataSource
ID="ObjectDataSource1"
runat="server"
SelectMethod="SelectMethod"
TypeName="Samples.AspNet.CS.SortingData"
SortParameterName="sortExpression">
</asp:ObjectDataSource>
</div>
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB" Assembly="Samples.AspNet.VB" %>
<%@ 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">
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="GridView1"
runat="server"
DataSourceID="ObjectDataSource1"
AllowSorting="True">
</asp:GridView>
<asp:ObjectDataSource
ID="ObjectDataSource1"
runat="server"
SelectMethod="SelectMethod"
TypeName="Samples.AspNet.VB.SortingData"
SortParameterName="sortExpression">
</asp:ObjectDataSource>
</div>
</form>
</body>
</html>
Remarks
The SortParameterName property is used to support data source sorting. When a SortExpression property is set on the DataSourceSelectArguments object and passed to the Select method, the SortParameterName value identifies the parameter name of the SelectMethod business object method according to which the data is sorted.
If the ObjectDataSource is associated with a data-bound control, the values that are passed to this parameter take the form of comma-separated field values followed by "ASC" or "DESC". For example, the value for an ascending sort on Name would be "Name ASC".
The SortParameterName property delegates to the SortParameterName property of the ObjectDataSourceView object that is associated with the ObjectDataSource control.
