ASP.NET GridView Paging - Handle Last Page Button

Question

I'm trying to make use of asp:GridView's built in paging functionality, but cannot seem to get the "Last Page" button to work when the mode is set to NumericFirstLast. Here's the code sample:

<asp:GridView ID="GridView1" runat="server" AllowSorting="true" AllowPaging="true" 
    PagerSettings-Mode="NumericFirstLast" PageSize="15"
    OnPageIndexChanging="GridView1_PageIndexChanging">
    <%-- Column Definitions --%>
</asp:GridView>

// C# Behind
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        LoadGrid();
    }
}

public void LoadGrid()
{
    // Assign DataSource
    GridView1.DataBind();
}

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    LoadGrid();
}

What's happening is when the last button is being clicked on the pager e.NewPageIndex holds a value of -1, meaning the assignment throws an exception. However, the GridView1.PageCount during the index changing event is 0 so I cannot use that to set the page index to count - 1. Any suggestions as to what is going on with this code or why I am receiving a -1 from the event args?

Answer 1

Well, I cannot explain why, nor find the answer in MSDN documentation, but as Ehsan suggested in the comments above, when e.NewPageIndex == -1 if you set GridView1.PageIndex to Int32.MaxValue it forces the grid to the last page.

If anyone happens to find documentation for why/how this works, please post a comment to that!