I've got a combobox in my WPF application:
<ComboBox ItemsSource="{Binding CompetitorBrands}" DisplayMemberPath="Value"
SelectedValuePath="Key" SelectedValue="{Binding Path=CompMfgBrandID, Mode=TwoWay,
UpdateSourceTrigger=PropertyChanged}" Text="{Binding CompMFGText}"/>
Bound to a collection of KeyValuePair<string, string>
Here is the CompMfgBrandID property in my ViewModel:
public string CompMfgBrandID
{
get { return _compMFG; }
set
{
if (StockToExchange != null && StockToExchange.Where(x => !string.IsNullOrEmpty(x.EnteredPartNumber)).Count() > 0)
{
var dr = MessageBox.Show("Changing the competitor manufacturer will remove all entered parts from the transaction. Proceed?",
"Transaction Type", MessageBoxButtons.YesNo, MessageBoxIcon.Warning);
if (dr != DialogResult.Yes)
return;
}
_compMFG = value;
StockToExchange.Clear();
...a bunch of other functions that don't get called when you click 'No'...
OnPropertyChanged("CompMfgBrandID");
}
}
If you choose "yes", it behaves as expected. Items are cleared and the remaining functions are called. If I choose 'No', it returns and doesn't clear my list or call any of the other functions, which is good, but the combobox still displays the new selection. I need it to revert back to the original selection, as if nothing had changed, when the user picks 'No'. How can I accomplish this? I also tried adding e.Handled = true
in codebehind, to no avail.
Very simple solution for .NET 4.5.1+:
<ComboBox SelectedItem="{Binding SelectedItem, Delay=10}" ItemsSource="{Binding Items}" />
It's works for me in all cases. You can rollback selection in combobox, just fire NotifyPropertyChanged without value assignment.