Sorting a ListView with a Data Pager

Question

User682008122 posted

I have a listview that I bind using  custom code in the code behind:

DataSet ds = jdh.GetDataSetFromDB(SQL);
lv_positions_i_posted.DataSource = ds;
lv_positions_i_posted.DataBind();

The ListView has a DataPager

<asp:DataPager ID="DataPager1" runat="server" PagedControlID="lv_positions_i_posted" PageSize="20">
	<Fields>
		<asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="True" ShowNextPageButton="False" ShowPreviousPageButton="False" />
                <asp:NumericPagerField ButtonCount="10" />
                <asp:NextPreviousPagerField ButtonType="Button" ShowLastPageButton="True" ShowNextPageButton="False" ShowPreviousPageButton="False" />
       </Fields>
</asp:DataPager>

I created a custom sort routine that successfully sorts the list view.

<asp:UpdatePanel ID="UpdatePanel3" runat="server" UpdateMode="conditional">
	<ContentTemplate>
        	<asp:ImageButton ID="SortPostingButton" runat="server" ImageUrl="~/images/Up2.png" Height="20px" Width="20px" ToolTip="Sort" OnClick="PostingSort1_Click" />        	</ContentTemplate>
  	<Triggers>
        	<asp:AsyncPostBackTrigger ControlID="SortPostingButton" />
   	</Triggers>
</asp:UpdatePanel>

The above snippet calls a routine that builds a SQL Statement which is applied to the fist code snippet above:

DataSet ds = jdh.GetDataSetFromDB(SQL);
lv_positions_i_posted.DataSource = ds;
lv_positions_i_posted.DataBind();

This ALL works ok. The issue is that if I change the page using the datapager, the sort is not maintained (i.e. page 2 and up are not sorted)

Here is the code for the listview:

 <asp:ListView ID="lv_positions_i_posted" runat="server" DataKeyNames="postingid" OnPagePropertiesChanging="lv_positions_i_posted_paging" OnItemDataBound="lv_positions_i_posted_ItemDataBound">
<LayoutTemplate>
    <table id="Table2" runat="server">
        <tr id="Tr1" runat="server">
            <td id="Td1" runat="server">
                <table id="itemPlaceholderContainer" runat="server" border="1"
                    style="border-collapse: collapse; border-color: #999999; border-style: none; border-width: 1px; font-family: Verdana, Arial, Helvetica, sans-serif;">
                    <tr>
                        <th colspan="2" style="background-color: darkseagreen;">Posting</th>
                        <th colspan="1" style="background-color: sandybrown;">Applications</th>
                        <th colspan="4">Positions I Posted</th>
                    </tr>
                    <tr id="Tr2" runat="server" style="color: #000000;">
                        <th id="Th1" runat="server" style="background-color: darkseagreen;">View</th>
                        <th id="Th2" runat="server" style="background-color: darkseagreen;">Edit</th>
                        <th id="Th3" runat="server" style="background-color: sandybrown;">View</th>
                        <th id="Th4" runat="server">ID</th>
                        <th id="Th6" runat="server">Title</th>
                        <th id="Th8" runat="server">Posting Date

                             <asp:UpdatePanel ID="UpdatePanel3" runat="server" UpdateMode="conditional">
                                 <ContentTemplate>
 <asp:ImageButton ID="SortPostingButton" runat="server" ImageUrl="~/images/Up2.png" Height="20px" Width="20px" ToolTip="Sort" OnClick="PostingSort1_Click" /> 
                                 </ContentTemplate>
                                 <Triggers>
 <asp:AsyncPostBackTrigger ControlID="SortPostingButton" />
                                 </Triggers>
                             </asp:UpdatePanel>

                         </th>
                        <th id="Th9" runat="server">Status
                            <asp:ImageButton ID="SortStatusButton" runat="server" ImageUrl="~/images/Up2.png" Height="20px" Width="20px" ToolTip="Sort" OnClick="StatusSort1_Click" />
                        </th>
                    </tr>
                    <tr id="itemPlaceholder" runat="server">
                    </tr>
                </table>
            </td>
        </tr>
        <tr id="Tr3" runat="server">
            <td id="Td2" runat="server"
                style="text-align: center; background-color: #CCCCCC; font-family: Verdana, Arial, Helvetica, sans-serif; color: #000000;">
                <asp:DataPager ID="DataPager1" runat="server" PagedControlID="lv_positions_i_posted" PageSize="20">
                    <Fields>
                        <asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="True"
                            ShowNextPageButton="False" ShowPreviousPageButton="False" />
                        <asp:NumericPagerField ButtonCount="10" />
                        <asp:NextPreviousPagerField ButtonType="Button" ShowLastPageButton="True"
                            ShowNextPageButton="False" ShowPreviousPageButton="False" />
                    </Fields>
                </asp:DataPager>
                &nbsp;
            </td>
        </tr>
    </table>
</LayoutTemplate>
<ItemTemplate>
    <tr style="background-color: #DCDCDC; color: #000000; font-weight: normal;">
        <td style="text-align: center">
            <asp:ImageButton ID="ViewPostingButton" runat="server" ToolTip="View Posting" ImageUrl="~/images/green-eye-icon-new-small.png" Width="30px" Height="18.75px" OnCommand="ViewPostingButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>
        <td style="text-align: center">
            <asp:ImageButton ID="EditPostingButton" runat="server" ToolTip="Edit Posting" ImageUrl="~/images/pencil_small.png" Width="18.75px" Height="18.75px" OnCommand="EditPostingButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>

        <td style="text-align: center">
            <asp:ImageButton ID="ViewPostingApplicantButton" runat="server" ToolTip="View Applicants" ImageUrl="~/images/green-eye-icon-new-small.png" Width="30px" Height="18.75px" ImageAlign="Middle" OnCommand="ViewPostingApplicantButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>
        <td style="text-align: center">
            <asp:Label ID="PostingID" runat="server" Text='<%# Eval("PostingID") %>' Visible="true" />
        </td>
        <td>
            <asp:Label ID="PostingTitle" runat="server" Text='<%# Eval("PostingTitle") %>' Visible="true" ToolTip='<%# Eval("PostingTitleFull") %>' />
        </td>
        <td style="text-align: center">
            <asp:Label ID="PostingDate" runat="server" Text='<%# Eval("PostingDate","{0:MM/dd/yyyy}") %>' Visible="true" />
        </td>


        <td style="text-align: center">
            <asp:Label ID="PostingStatusID" runat="server" Text='<%# Eval("PostingStatusID") %>' Visible="true" />
        </td>
    </tr>
</ItemTemplate>
<AlternatingItemTemplate>
    <tr style="background-color: #FFF8DC; color: #000000; font-weight: normal;">
        <td style="text-align: center">
            <asp:ImageButton ID="ViewPostingButton" runat="server" ToolTip="View Posting" ImageUrl="~/images/green-eye-icon-new-small.png" Width="30px" Height="18.75px" OnCommand="ViewPostingButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>
        <td style="text-align: center">
            <asp:ImageButton ID="EditPostingButton" runat="server" ToolTip="Edit Posting" ImageUrl="~/images/pencil_small.png" Width="18.75px" Height="18.75px" OnCommand="EditPostingButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>

        <td style="text-align: center">
            <asp:ImageButton ID="ViewPostingApplicantButton" ToolTip="View Applicants" runat="server" ImageUrl="~/images/green-eye-icon-new-small.png" Width="30px" Height="18.75px" ImageAlign="Middle" OnCommand="ViewPostingApplicantButton_Click" CommandArgument='<%#Eval("PostingID")%>' />

        </td>
        <td style="text-align: center">
            <asp:Label ID="PostingID" runat="server" Text='<%# Eval("PostingID") %>' Visible="true" />
        </td>
        <td>
            <asp:Label ID="PostingTitle" runat="server" Text='<%# Eval("PostingTitle") %>' Visible="true" ToolTip='<%# Eval("PostingTitleFull") %>' />
        </td>
        <td style="text-align: center">
            <asp:Label ID="PostingDate" runat="server" Text='<%# Eval("PostingDate","{0:MM/dd/yyyy}") %>' Visible="true" />
        </td>


        <td style="text-align: center">
            <asp:Label ID="PostingStatusID" runat="server" Text='<%# Eval("PostingStatusID") %>' Visible="true" />
        </td>
    </tr>
</AlternatingItemTemplate>
<EmptyDataTemplate>
    <table id="Table1" runat="server"
        style="background-color: #FFFFFF; border-collapse: collapse; border-color: #999999; border-style: none; border-width: 1px;">
        <tr>
            <td>No data was returned.</td>
        </tr>
    </table>
</EmptyDataTemplate>
 </asp:ListView>

Here is how I Bind the ListView

protected void BindListview(string selectedItem, string orderby)
    {
        string SQL = "";
        string direction = "";
            SQL = "Select  Statment Here";
            if (orderby != "")
            {
                if (selectedItem == TheListView.Text)
                {
                    if (orderby == LastSortField.Text)
                    {
                        if (LastSortDirection.Text == "asc")
                        {
                            direction = "desc";
                        }
                        else
                        {
                            direction = "asc";
                        }
                        SQL += " Order by " + orderby + " " + direction;
                        LastSortDirection.Text = direction;
                        LastSortField.Text = orderby;
                    }
                    else
                    {
                        SQL += " Order by " + orderby;
                        LastSortDirection.Text = "asc";
                        LastSortField.Text = orderby;
                    }
                }
                else
                {
                    SQL += " Order by '" + orderby ;
                    LastSortDirection.Text = "asc";
                    LastSortField.Text = orderby;
                }
            }
            else
            {
                    SQL += " Order by PostingID asc";
                    LastSortDirection.Text = "asc";
                    LastSortField.Text = "PostingID";
            }
            DataSet ds = jdh.GetDataSetFromDB(SQL);
            lv_positions_i_posted.DataSource = ds;
            lv_positions_i_posted.DataBind();
            lv_positions_i_posted.Visible = true;
            ds.Dispose();
        }

Answer 1

User839733648 posted

Hi Whalensdad,

According to your description and code, I'm sorry that I could not reproduce your issue successfully.

protected void BindListview(string selectedItem, string orderby)

Some various like TheListView,LastSortField in the above event could not work well, and I could not find these keywords elsewhere.

Also, I want to ask that where do you call the BindListview event. Maybe this has affected the issue.

Best Regards,

Jenifer

Answer 2

User682008122 posted

Jenifer - I actually figured it out about 20 min ago.

I forgot that I captured the datapager page change and was not passing in the "orderby" variable. Once I fixed that it works correctly.

protected void lv_positions_i_manage_paging(object sender, PagePropertiesChangingEventArgs e)
{
    (lv_positions_i_manage.FindControl("DataPager1") as DataPager).SetPageProperties(e.StartRowIndex, e.MaximumRows, false);
    if (LastSortDirection.Text == "asc")
    {
        LastSortDirection.Text = "desc";
    }
    else
    {
        LastSortDirection.Text = "asc";
    }

        BindListview("2", LastSortField.Text);
}

Answer 3

User839733648 posted

Hi Whalensdad,

I suggest that you coud mark your  solution as answer if it solved your problem.

And this will be helpful for someone meets with the same problem. 

Best Regards,

Jenifer