Sorting asp.net GridView with SPDataSource - asp.net

Question

I would like to sort my GridView by clicking on the column's header. So far I declared a SPDataSource
<SharePoint:SPDataSource
runat="server"
ID="SPdsInventarGrid"
DataSourceMode="List"
UseInternalName="true"
Scope="Recursive"
SelectCommand="<View><Query><Where><Or><Neq><FieldRef Name='EBS_x002e_CN_x002e_Inventar_x00210' /><Value Type='Text'>Open</Value></Neq><IsNull><FieldRef Name='EBS_x002e_CN_x002e_Inventar_x0028' /></IsNull></Or></Where></Query><ViewFields><FieldRef Name='Title'/><FieldRef Name='ID'/><FieldRef Name='EBS_x002e_CN_x002e_Inventar_x0028'/><FieldRef Name='EBS_x002e_CN_x002e_Inventar_x00210'/><FieldRef </ViewFields></View>">
<SelectParameters>
<asp:Parameter Name="ListName" DefaultValue="Inventar" />
</SelectParameters>
</SharePoint:SPDataSource>
Then I created my grid, based on the datasource
<asp:GridView Visible="true" Width="100%"
ID="gvInventar"
AutoGenerateColumns="false" runat="server" CellPadding="2" AllowPaging="false" AllowSorting="true" OnSorted="gvInventar_Sorted" OnSorting="gvInventar_Sorting" GridLines="None" DataSourceID="SPdsInventarGrid" OnRowCommand="gvInventar_RowCommand">
<Columns>
<asp:CommandField ButtonType="Image" ShowEditButton="true" EditImageUrl="/_layouts/images/edit.gif" UpdateImageUrl="/_layouts/images/save.gif" CancelImageUrl="/_layouts/images/delete.gif" />
<asp:TemplateField HeaderText="ID">
<ItemTemplate>
<asp:Label Text='<%# Bind("ID") %>' runat="server" ID="lblIdProduct"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Title" >
<ItemTemplate>
<asp:Label Text='<%# Bind("Title") %>' runat="server" ID="lblTitleProduct" ></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Product" SortExpression="Product">
<ItemTemplate>
<asp:Label Text='<%# Bind("EBS_x002e_CN_x002e_Inventar_x0028") %>' runat="server" ID="lblProduct" "></asp:Label>
</ItemTemplate>
</Columns>
</asp:GridView>
Now, I have this function where I wanted to get the current Query as a string and add <OrderBy>(my field) before <Query> but i get an error saying that the DataSource has been already declared (which is true because i want to be declared in asp)
protected void gvInventar_Sorting(object sender, GridViewSortEventArgs e)
{
SPQuery q = new SPQuery();
q.Query = SPdsInventarGrid.SelectCommand;
switch (e.SortExpression)
{
case "Product":
if (e.SortDirection == SortDirection.Ascending)
{
gvInventar.DataSource = q.Query;
gvInventar.DataBind();
}
else
{
}
break;
}
}
Even though it's not working this way, I don't think modifying the Query is the solution.
Could anyone help me with this matter?

Answer 1

You don't need to write any custom code to sort the gridview by clicking the column headers, all you have to do is set the SortExpression property of the TemplateField to the required column name, e.g:
<Columns>
<asp:TemplateField HeaderText="ID" SortExpression="ID">
<ItemTemplate>
<asp:Label Text='<%# Bind("ID") %>' runat="server" ID="lblIdProduct" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Title" SortExpression="Title">
<ItemTemplate>
<asp:Label Text='<%# Bind("Title") %>' runat="server" ID="lblTitleProduct" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Product" SortExpression="EBS_x002e_CN_x002e_Inventar_x0028">
<ItemTemplate>
<asp:Label Text='<%# Bind("EBS_x002e_CN_x002e_Inventar_x0028") %>' runat="server"
ID="lblProduct" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
Now you can sort on all 3 columns: