listbox isSelected databinding in DataTemplate
- by Kinmarui
I try to simply databind IsSelected property with IsSelected field in my class.
But after I change the value in code its doesn't change the property, neither does clicking on ListBoxItem change the field value.
XAML:
<FlipView ItemsSource="{Binding Source={StaticResource itemsViewSource}}" ... >
<FlipView.ItemTemplate>
<DataTemplate>
<UserControl Loaded="StartLayoutUpdates" Unloaded="StopLayoutUpdates">
<!-- other controls -->
<ListBox Grid.Row="1" Grid.ColumnSpan="3" SelectionMode="Multiple" VerticalAlignment="Center" ItemsSource="{Binding Answers}">
<ListBox.Resources>
<local:LogicToText x:Key="logToText" />
</ListBox.Resources>
<!-- bind IsSelected only in one way from code to content -->
<ItemsControl.ItemTemplate>
<DataTemplate>
<ListBoxItem IsSelected="{Binding IsSelected, Mode=TwoWay, Converter={StaticResource logToText}}" Content="{Binding IsSelected, Mode=TwoWay, Converter={StaticResource logToText}}">
</ListBoxItem>
</DataTemplate>
</ItemsControl.ItemTemplate>
<!-- not working at all
<ListBox.Resources>
<Style TargetType="ListBoxItem">
<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>
<Setter Property="Content" Value="{Binding IsSelected, Mode=TwoWay}"/>
</Style>
</ListBox.Resources>-->
</ListBox>
</UserControl>
</DataTemplate>
</FlipView.ItemTemplate>
</FlipView>
Code:
Answers
private ObservableCollection<PrawoJazdyDataAnswer> _answers = new ObservableCollection<PrawoJazdyDataAnswer>();
public ObservableCollection<PrawoJazdyDataAnswer> Answers { get { return this._answers; } }
Single item(Answer)
public class PrawoJazdyDataAnswer : NPCHelper// PrawoJazdy.Common.BindableBase
{
public PrawoJazdyDataAnswer(String ans, bool ansb)
{
this._ans = ans;
this._isSelected = ansb;
}
public override string ToString() { return _isSelected.ToString(); } //Only For debug purposes normally return _ans;
private string _ans;
public string Ans
{
get { return this._ans; }
//set { this.SetProperty(ref this._ans, value); }
}
private bool _isSelected;
public bool IsSelected
{
get { return this._isSelected; }
set
{
_isSelected = value;
FirePropertyChanged("IsSelected");
//this.SetProperty(ref this._isSelected, value);
}
}
}
FirePropertyChanged
public class NPCHelper : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void FirePropertyChanged(string prop)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(prop));
}
}
Converter(which sometimes seems to be needed and others not..., I tried ~10 approaches from different tutorials/examples)
public class LogicToText : IValueConverter
{
/// <summary>
///
/// </summary>
public object Convert(object value, Type targetType, object parameter, string language)
{
//if (value == null || (bool)value == false)
// return "False";
return value.ToString();
}
/// <summary>
///
/// </summary>
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
return value.ToString().Contains("True") ? true : false;
}
Thanks in advance, and sorry for my English(still learning).
@edit
Thanks for quick reply.
For test purposes i created a button and text block:
It's in other controls part (above list box, but in FlipView)
<Button Click="spr" >Sprawdz</Button>
<TextBlock Text="{Binding Answers[0].IsSelected, Mode=TwoWay}" > </TextBlock>
Click method
private void spr(object sender, RoutedEventArgs e)
{
var ans = ((PrawoJazdyDataQuestion)this.flipView.SelectedItem).Answers;
foreach (var item in ans)
item.IsSelected = item.IsSelected ? false : true;
}
As I wrote when i'm changing data from code side its change text, but not appearance of ListBoxItem, and if i just select it on ListBox its doesn't change the date i textblock neither in ListBox itself.
