这个网格视图有两列需要排序。
问题是我得到一个将数据绑定到gridview数据源的类列表,点击grid列时,sort表达式会触发,但数据源为null,所以我怎样才能实现这一点。
标记:
<asp:GridView ID="grdDelegateList" runat="server" CssClass="gridviewBorder" AutoGenerateColumns="False" AllowSorting="true"
EmptyDataText="There are no delegates assigned for this bridge." CellPadding="2"
Style="margin-left: 0px" BackColor="White" Font-Names="Calibri" BorderWidth="1px"
Width="100%" AllowPaging="True" GridLines="Horizontal" RowHoverBackColor="#666666"
RowHoverForeColor="White" SelectedRowStyle-BackColor="#333333" SelectedRowStyle-ForeColor="White"
PageSize="20" OnPageIndexChanging="grdDelegateList_PageIndexChanging" OnRowCommand="grdDelegateList_RowCommand"
OnRowDataBound="grdDelegateList_RowDataBound"
OnRowDeleting="grdDelegateList_RowDeleting" onsorting="grdDelegateList_Sorting">
<Columns>
<asp:BoundField HeaderText="Employee ID" DataField="DelegateID" ItemStyle-HorizontalAlign="Center" SortExpression="DelegateID"
HeaderStyle-HorizontalAlign="Center" />
<asp:BoundField HeaderText="Display Name" DataField="FullName" ItemStyle-HorizontalAlign="Left" SortExpression="FullName"
HeaderStyle-HorizontalAlign="Left" />
<asp:TemplateField HeaderText="Remove" ItemStyle-HorizontalAlign="Left" HeaderStyle-HorizontalAlign="Left">
<ItemTemplate>
<span style="cursor: pointer">
<asp:LinkButton ID="ImgRemove" runat="server" CommandName="Delete" CommandArgument='<%# Eval("ID") %>'
Text="Remove" OnClientClick="return confirm('Are you sure you want to remove this Delegate');">
<img alt="Remove" src="Images/trash.png" style="border:0;" />
</asp:LinkButton></span>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
排序表达式事件:
protected void grdDelegateList_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable table = grdDelegateList.DataSource as DataTable;//this is coming null
if (table != null)
{
DataView dataView = new DataView(table);
dataView.Sort = e.SortExpression + " " + ConvertSortDirection(e.SortDirection);
grdDelegateList.DataSource = dataView;
grdDelegateList.DataBind();
}
}
private string ConvertSortDirection(SortDirection sortDirection)
{
string newSortDirection = String.Empty;
switch (sortDirection)
{
case SortDirection.Ascending:
newSortDirection = "ASC";
break;
case SortDirection.Descending:
newSortDirection = "DESC";
break;
}
return newSortDirection;
}
由于数据源是null,我是否需要再次从db获取数据,如果是,我正在获取列表,所以我需要添加cutom逻辑以首先将列表转换为数据表或将它也适用于列表。有什么建议??
答案 0 :(得分:0)
您将获得null,因为数据源是列表而不是当前方案中的数据表。因此,当您绑定网格时,使用列表中已转换的数据表会更好。其余的排序逻辑将不受影响。
<强>更新强>
将数据表保留在会话中。在从会话中对数据表进行排序后,在排序事件中检索并重新绑定网格。另外,不要忘记更新会话表以及更新的排序表达式。见http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.sorting.aspx