How do I programatically clear the HasSelection property of the WebGrid?

Question

Self explanatory question.

Between posts, the grid I have setup is retaining the HasSelection bit, even if the WebGrid has been re-loaded with new data. Therefore, the functionality I have wired into the physical selection of a WebGrid record runs, even though the user hasn't selected anything on the new resultset yet.

Thoughts?

Answer 1

WebGrid obtains the selected row thru the query string. by default, the query string field is row like http://localhost/grid?row=2

Ideally, you would remove that query string field before posting back like so http://localhost/grid

If it is not possible, set WebGrid.SelectedIndex to -1 instead.

Edit

Here are few ways to set WebGrid.SelectedIndex:

@{
    WebGrid grid = new WebGrid(Model);
    grid.SelectedIndex = ViewBag.SelectedIndex;
    @grid.GetHtml(
        columns: grid.Columns(
            ...
        )
    )
}

public ActionResult Index(int? row)
{
    ViewBag.SelectedIndex = (IsKeepSelection() ? row.GetValueOrDefault() : 0) - 1; //TODO: add bound checking
    return View(People.GetPeople());
}

Or (I prefer the previous one though since it's easier to understand):

@{
    WebGrid grid = new WebGrid(Model);
    if(ViewBag.ClearSelection) {
        grid.SelectedIndex = -1;
    }
    @grid.GetHtml(
        columns: grid.Columns(
            ...
        )
    )
}

public ActionResult Index(int? row)
{
    ViewBag.ClearSelection = IsClearSelection();
    return View(People.GetPeople());
}