Question

The datatemplate for the ListBox is set dynamically by XamlReader.Load. I am subscribing to Checked event by getting the CheckBox object using VisualTreeHelper.GetChild. This event is not getting fired

Code Snippet

    public void SetListBox()
    {
        lstBox.ItemTemplate =
        XamlReader.Load(@"<DataTemplate xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' x:Name=""DropDownTemplate""><Grid x:Name='RootElement'><CheckBox  x:Name='ChkList' Content='{Binding " + TextContent + "}' IsChecked='{Binding " + BindValue + ", Mode=TwoWay}'/></Grid></DataTemplate>") as DataTemplate;

        CheckBox  chkList = (CheckBox)GetChildObject((DependencyObject)_lstBox.ItemTemplate.LoadContent(), "ChkList");

        chkList.Checked += delegate { SetSelectedItemText(); };
    }

    public CheckBox GetChildObject(DependencyObject obj, string name) 
    {
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
        {
            DependencyObject c = VisualTreeHelper.GetChild(obj, i);
            if (c.GetType().Equals(typeof(CheckBox)) && (String.IsNullOrEmpty(name) || ((FrameworkElement)c).Name == name))
            {
                return (CheckBox)c;
            }
            DependencyObject gc = GetChildObject(c, name);
            if (gc != null)
                return (CheckBox)gc;
        }
        return null;
    }

How to handle the checked event? Please help

Answer 1

Removed ItemTemplate and added the below code

                var checkBox = new CheckBox { DataContext = item };
                if (string.IsNullOrEmpty(TextContent)) checkBox.Content = item.ToString();
                else
                    checkBox.SetBinding(ContentControl.ContentProperty,
                                        new Binding(TextContent) { Mode = BindingMode.OneWay });
                if (!string.IsNullOrEmpty(BindValue))
                    checkBox.SetBinding(ToggleButton.IsCheckedProperty,
                                        new Binding(BindValue) { Mode = BindingMode.TwoWay });
                checkBox.SetBinding(IsEnabledProperty, new Binding("IsEnabled") { Mode = BindingMode.OneWay });
                checkBox.Checked += (sender, RoutedEventArgs) => { SetSelectedItemText(true, ((CheckBox)sender).GetValue(CheckBox.ContentProperty).ToString()); };
                checkBox.Unchecked += (sender, RoutedEventArgs) => { SetSelectedItemText(true, ((CheckBox)sender).GetValue(CheckBox.ContentProperty).ToString()); };

This fixed the issue