Prevent checkbox uncheck event when datagrid is in invalid state

Question

In Silverlight (but will probably equally apply to wpf) I have a datagrid which has validation and can go into an invalid state. I check this by:

if(grid.IsValid)
{
    ...
}

I have a checkbox that triggers saving when unchecked, I wish for this checkbox to be disabled, or at least not uncheck if the grid is in an invalid state.

Something like:

BeforeUncheckEvent
{
    if(datagridisvalid)
        allow;
    else
        disallow;
}

Binding to the IsEnabled based on the grids IsValid would be even better. This does not work:

IsEnabled="{Binding ElementName=grid, Path=IsValid, UpdateSourceTrigger=PropertyChanged}"

UPDATE>>

I have tried binding another checkbox to the grids IsValid and that works, even when the other checkbox is almost identical to the one that does not work.

SOME CODE>>

When I check this :

    <CheckBox x:Name="chkAllowManual" Checked="chkAllowManual_Checked" Unchecked="chkAllowManual_Unchecked" Content="Allow Manual" VerticalAlignment="Center" Margin="3,0,7,0" IsEnabled="{Binding ElementName=grdPrices, Path=IsValid}">
    </CheckBox>

The grid gets its itemsource set, has some errors after edit then this gets disabled properly (not the original checkbox but the one next to it) :

    <CheckBox x:Name="chkAllowManual1" Checked="chkAllowManual_Checked" Unchecked="chkAllowManual_Unchecked" Content="Allow Manual1" VerticalAlignment="Center" Margin="3,0,7,0" IsEnabled="{Binding ElementName=grdPrices, Path=IsValid}">
    </CheckBox>

Any ideas?

bro will need to see your code xaml and codebehind to crack this.. ideally it should work — Nitin
What error did you get when you tried the IsEnabled binding that you say didn't work? (You can find errors in the Output Window in Visual Studio.) — Sheridan
@Sheridan no error. I am beginning to think the binding gets removed as a converter attached to it does not even get called when the IsInvalid=true ... all I do after the initial binding and it not working is reset the itemsource of the grid, maybe that is doing it somehow... — sprocket12

Sheridan Sheridan · Accepted Answer · 2013-09-05T16:27:42

If you have access to a reference of your DataGrid wherever the Checked handler is, then you could try doing this:

private void chkAllowManual_Checked(object sender, RoutedEventArgs e)
{
    if (!dataGrid.IsValid) e.Handled = true;
    else
    {
        // do your stuff here
    }
}

This should stop it from becoming checked when dataGrid.IsValid is flase.

Prevent checkbox uncheck event when datagrid is in invalid state

1 Answers