WPF multiple-condition binding filtering - wpf

Question

I am new to WPF and all this magical binding and datatriggers stuff, so i ask you for a little help.
I have a simple wpf app shown on picture below.
I want my datagrid contents to reflect conditions and date filter. I already figured out how to bind datagrid rows visibility depending on event codes and checkboxes (start, stop, error). But i cant't figure out how to implement date filtering. All i want is: when "Filter by date" checkbox is checked, in my datagrid only those rows remain visible, which have date in "server time" field (i guess i need to parse it somehow from datetime) equal to selected date combobox.
Can i achieve that using xaml only? Can enyone help me to do that?
Here is xaml for my datagrid:
<DataGrid
Grid.Row="1"
Margin="5"
AutoGenerateColumns="False"
IsReadOnly="True"
ItemsSource="{Binding LogEntries}"
Style="{DynamicResource Helvetica}">
<DataGrid.RowStyle>
<Style TargetType="DataGridRow">
<Style.Triggers>
<DataTrigger Binding="{Binding event_code}" Value="1">
<Setter Property="Background" Value="LightGreen" />
<Setter Property="Visibility" Value="{Binding IsChecked, ElementName=StartShowChecked, Converter={StaticResource BooleanToVisibilityConverter}}" />
</DataTrigger>
<DataTrigger Binding="{Binding event_code}" Value="2">
<Setter Property="Background" Value="LightGray" />
<Setter Property="Visibility" Value="{Binding IsChecked, ElementName=StopShowChecked, Converter={StaticResource BooleanToVisibilityConverter}}" />
</DataTrigger>
<DataTrigger Binding="{Binding event_code}" Value="3">
<Setter Property="Background" Value="#FFEA816F" />
<Setter Property="Visibility" Value="{Binding IsChecked, ElementName=ErrorShowChecked, Converter={StaticResource BooleanToVisibilityConverter}}" />
</DataTrigger>
</Style.Triggers>
</Style>
</DataGrid.RowStyle>
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding server_datetime, StringFormat=\{0:dd.MM.yy HH:mm:ss\}}" Header="Server time" />
<DataGridTextColumn Binding="{Binding user_datetime, StringFormat=\{0:dd.MM.yy HH:mm:ss\}}" Header="Client time" />
<DataGridTextColumn
Width="*"
Binding="{Binding log_entry}"
Header="Entry" />
</DataGrid.Columns>

Answer 1

Can i achieve that using xaml only?
No you can't because XAML is a markup language and nothing else.
What you shold do is to bind the SelectedItem of the date ComboBox to a DateTime property of your view model and bind the IsChecked property of the "filter by" CheckBox to a bool property of your view model and filter the LogEntries source collection when the IsChecked source property is set, e.g.:
public class ViewModel : INotifyPropertyChanged
{
private bool _isChecked;
public bool IsChecked
{
get { return _isChecked; }
set
{
_isChecked = value;
OnPropertyChanged();
//filter collection:
LogEntries = allLogEntries.Where(x => x.ServerTime == SelectedDate).ToList();
}
}
private List<LogEntry> _logEntries;
public List<LogEntry LogEntries
{
get { return _logEntries; }
set
{
_logEntries = value;
OnPropertyChanged();
}
}
//...
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}

Answer 2

I doubt there is a way to do it in XAML only, since filtering requires you to specify how to filter (for example by creating a predicate).
What I recommend is getting an ICollectionView from your ItemsSource (which I assume is an ObservableCollection) and set it's Filter property.
Check out this answer for more details : Filter a DataGrid in WPF