I'm writing a custom server control (composite) in which one of the
contained controls is a 'pageable' datagrid. I'm adding a custom
templateColumn to the grid programmatically, which is a checkbox, a
BoundColumn which displays a person's name and another BoundColumn, which
is NOT visible that holds their unique Guid.
I want to display 5 names at a time, allow the user to select items via
the checkboxes, page back and forth within the grid and still maintain the
state of the checkboxes on returning to, let's say, a previously viewed
datagrid page.
To do this, I've tried two different methods:
1. I've registered the PageIndexChanged event within my server control to
be handled by a method within the server control.
eg.
UserGrid.PageIndexChanged += new DataGridPageChangedEventHandler
(DataGrid_PageChanged);
private void DataGrid_PageChanged(object sender,
DataGridPageChangedEventArgs e)
{
//A method that determines which people were selected and stores
their information in a stateful property before changing the
datagrid's pageindex and rebinding.
DetermineSelectedMembers();
UserGrid.CurrentPageIndex = e.NewPageIndex;
SetDataGridSettings();
UserGrid.DataBind();
}
And in this method, after the DataBind() method call, I loop through the
datagrid items (should be present since I just bound the data to it) and
test one of my viewstate values for a person's guid and if they've been
chosen before, check the checkbox. This doesn't work and it seems as if
the PageIndexChanged event fires when I'm paging forward but not
backwards??????
2. The second thing I tried was just intercepting the ItemDataBound event
of the datagrid and trying to check the value of the hidden cell
containing the person's guid and comparing it with my maintained data
source of guids that have been selected across postbacks. This would work
great except that even though the datagrid pages display correctly, I'm
getting text contents of " " returned to me in the method??????
private void DataGrid_ItemDataBound(object sender, DataGridItemEventArgs e)
{
sMembers = SelectedMembers.Split(new char[] {'|'});
foreach (string member in sMembers)
{
string memberGuid = e.Item.Cells[2].Text.ToString();
if (memberGuid == member)
{
//This is where I step through, test the value of memberGuid and get
//" " and of course the data should be bound at this point, right?
//The data does, in fact, display correctly in the browser
CheckBox chk = new CheckBox();
chk = (CheckBox)e.Item.FindControl("SelectCheck");
chk.Checked = true;
}
}
I've thought that since the Guid field is "hidden" there wouldn't be
any "Text", so I tested this same code on a field that does display and I
got the same result, " ".
I'm stumped! Can somebody help me by shedding some light on this?
Thanks much,
Rachael
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