How to get TextBox inside DataTemplate in a ListBox to notify the ViewModel on value change
What I need to find is when a textbox's value is changing or the dropdown's value changes inside my datatemplate item, I need to be notified in my ViewModel.cs.
So basically as a user edits a textbox inside the listbox, the viewmodel will be notified as the values are changing.
The reason is I need to go through all my Entries and update something as items inside the listbox's datatemplate change.
Any suggetion?
I have the following in my XAML.
<ListBox x:Name="EntriesListBox"
ItemsSource="{Binding Path=Entries}"
Grid.Row="1">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<ComboBox x:Name="EntriesPropertyName"
Width="215"
Margin="0,0,5,0"
SelectedItem="{Binding Path=Property, Mode=TwoWay}"
ItemsSource="{Binding Source={StaticResource DataContextProxy},Path=DataSource.EntityTypeProperties}" />
<TextBox x:Name="EntriesPropertyValue"
Width="215"
Margin="0,0,5,0"
Text="{Binding Path=Value, Mode=TwoWay, BindsDirectlyToSource=True}" />
开发者_JS百科 </StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The following is in my VM (ViewModel.cs)
public ObservableCollection<Entry> Entries { get; set; }
The following is in my business object (Entry.cs)
public class Entry
{
public PropertyItem Property { get; set; }
public string Value { get; set; }
}
On your binding, set the UpdateSourceTrigger... Also implement INotifyPropertyChanged
Provided that you have setup your view model class properly (by implementing INotifyPropertyChanged), following is what you may want to do:
<TextBox x:Name="EntriesPropertyValue"
Width="215"
Margin="0,0,5,0"
Text="{Binding Path=Value, Mode=TwoWay, BindsDirectlyToSource=True, UpdateSourceTrigger=PropertyChanged}" />
This seems to work. Any reason not to do it this way?
private void EntriesPropertyValue_TextChanged(object sender, TextChangedEventArgs e)
{
(sender as TextBox).GetBindingExpression(TextBox.TextProperty).UpdateSource();
this.ViewModel.UpdateFinalQuery();
}
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