Binding Visibility of StackPanel in a ListBox.ItemTemplate

Question

Hi,

I'm trying to setup an item template which has a couple of nested StackPanels in it.  I'm trying to set the visibility of one of the panels to the IsSelected proprety of the ListBoxItem.  I've tried this with no luck:

        <ListBox Name="listBox1" Margin="0,0,0,0" SelectionChanged="listBox1_SelectionChanged">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Vertical">
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="This is where the person's info goes, picture, name, and stuff, the color of the row changes based on his status, and stuff like that" TextWrapping="Wrap" Height="100" Width="600"/>
                        </StackPanel>
                        <StackPanel Orientation="Horizontal" x:Name="buttonsPanel" Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsSelected, Converter={StaticResource BooleanToVisibilityConverter}}" >
                            <RadioButton x:Name="presentButton"  Content="Present" Width="100" ClickMode="Press" IsTabStop="False"/>
                            <RadioButton x:Name="absentButton" Content="Absent" Width="100" ClickMode="Press" IsTabStop="False"/>
                            <RadioButton x:Name="excusedButton" Content="Excused" Width="100" ClickMode="Press" IsTabStop="False"/>
                        </StackPanel>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

 The point is that the last StackPanel should only be displayed for the selected item.

Does anyone know what I'm doing wrong here?

Thanks

 

Answer 1

which version of Silverlight?  If 5, you can use Ancestor RelativeSource binding to get a reference to the ListBoxItem which is the control you're trying to reference.  Otherwise, maybe you could get creative with a converter and walk up the tree until you find a ListBoxItem.

Answer 2

I'm still using Silverlight 4. 

 

I guess I'll keep looking for a solution, since I can't upgrade at the moment.

Answer 3

Hi Ali,

Below is my test code, and the StackPanel only be displayed for the selected item. You may have a try.

.xaml

<UserControl x:Class="BindingVisibility.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
           xmlns:myproject="clr-namespace:BindingVisibility" 
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <UserControl.Resources>
        <myproject:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter" />     
    </UserControl.Resources>
    <Grid x:Name="LayoutRoot" Background="White">
       
        <ListBox Name="listBox1" Margin="0,0,0,0" >
            <ListBox.ItemContainerStyle>
                <Style TargetType="ListBoxItem">
                    <Setter Property="IsSelected" Value="{Binding Mode=TwoWay, Path=IsSelected}" >
                    </Setter>
                </Style>
            </ListBox.ItemContainerStyle>

                <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Vertical"   >
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="This is where the person's info goes, picture, name, and stuff, the color of the row changes based on his status, and stuff like that" TextWrapping="Wrap" Height="100" Width="600"/>
                        </StackPanel>
                        <TextBlock Text="{Binding Name}" />
                        
                        <StackPanel Orientation="Horizontal" x:Name="buttonsPanel" Visibility="{Binding Path=IsSelected,Converter={StaticResource BooleanToVisibilityConverter},Mode=TwoWay}"   >
                            <RadioButton x:Name="presentButton"  Content="Present" Width="100" ClickMode="Press" IsTabStop="False"/>
                            <RadioButton x:Name="absentButton" Content="Absent" Width="100" ClickMode="Press" IsTabStop="False"/>
                            <RadioButton x:Name="excusedButton" Content="Excused" Width="100" ClickMode="Press" IsTabStop="False"/>
                        </StackPanel>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</UserControl>

.cs

using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Collections.ObjectModel;
using System.Windows.Data;
using System.ComponentModel;

namespace BindingVisibility
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();         
            listBox1.ItemsSource = GridData.GetData();
        }          
    }

    public class GridData : INotifyPropertyChanged
    {
        public string Name { get; set; }
        public int Age { get; set; }
        public bool Male { get; set; }
        private bool isSelected;

        public bool IsSelected
        {
            get 
            { 
                return isSelected;
            }
            set 
            { 
                isSelected = value;
                NotifyPropertyChanged("IsSelected");
            }
        }

        public static ObservableCollection<GridData> GetData()
        {
            ObservableCollection<GridData> data = new ObservableCollection<GridData>();
            data.Add(new GridData()
            {
                Name = "John Doe",
                Age = 30,
                Male = true,
                IsSelected = false
            });
            data.Add(new GridData()
            {
                Name = "Jane Doe",
                Age = 32,
                Male = false,
                IsSelected = false
            });
            data.Add(new GridData()
            {
                Name = "Jason Smith",
                Age = 54,
                Male = true,
                IsSelected = false
            });
            data.Add(new GridData()
            {
                Name = "Kayli Jayne",
                Age = 25,
                Male = false,
                IsSelected = false
            });
            return data;
        }

        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
    } 
}

Any question on this issue, please let me know.

Best Regards,

Answer 4

Hi Haixia,

 

Thanks for the reply.

I tried to run your code, but ran into an exception when InitializeComponent is called:

{System.NotSupportedException: Cannot set read-only property ''.
   at MS.Internal.XamlMemberInfo.SetValue(Object target, Object value)
   at MS.Internal.XamlManagedRuntimeRPInvokes.SetValue(XamlTypeToken inType, XamlQualifiedObject& inObj, XamlPropertyToken inProperty, XamlQualifiedObject& inValue)}

It is on this line:

  <Setter Property="IsSelected" Value="{Binding Mode=TwoWay, Path=IsSelected}" >

I'm not realy sure why.  According to the docs IsSelected is not a read only property.                   

 

Answer 5

Hi Ali,

I suspect that you may have missed somthing, such as a reference or namespace. I have upload my test project( BooleanToVisibilityConvertertest) to skydrive , you may have a look.

Best Regards,

Answer 6

I get the same exact error running your sample application.

What version of Silverlight are you using?

Answer 7

Hi Ali,

I am using Silverlight 4, and have these installed: VS 2010, Microsoft Silverlight 4 Toolkit April 2010,Microsoft Silverlight 4 SDK.

Best Regards,

Answer 8

That's exactly what I'm using!  Wonder why it blows up on mine?

Answer 9

Hi Ali,

Do you have same issue when running other Silverlight applications? Please check if you have these three (VS 2010, Microsoft Silverlight 4 Toolkit April 2010 ,Microsoft Silverlight 4 SDK) installed.

Best Regards,

Answer 10

Nope, no problems with other Silverlight Apps. I double checked the version of the SDK and toolkit and they are the same as yours. And I'm using VS2010.

Answer 11

Hi Ali,

The test application I posted above indeed created at Silverlight 4 version. The issue is not arise at my side maybe have something to do with I have installed Silverlight 5 SDK on my machine.

Binding in style setters allows bindings to be used within styles to reference other properties is a new feature of Silverlight 5. So I will suggest you to install Silverlight 5.

If you really don't want to install Silverlight 5, you may try this Setter value binding helper.

http://blogs.msdn.com/b/delay/archive/2009/11/02/as-the-platform-evolves-so-do-the-workarounds-better-settervaluebindinghelper-makes-silverlight-setters-better-er.aspx

Best Regards,

Answer 12

Hi, It is dependency no reason to use Converter. However ListBox is Visaul Tree so that you can bind to ElementName. private Visibility _adminButtonsVisibility; public Visibility AdminButtonsVisibility { get { return _adminButtonsVisibility; } set { if (_adminButtonsVisibility != value) { _adminButtonsVisibility = value; OnPropertyChanged("AdminButtonsVisibility"); } } }

Answer 13

private Visibility _adminButtonsVisibility;
        public Visibility AdminButtonsVisibility
        {
            get { return _adminButtonsVisibility; }
            set
            {
                if (_adminButtonsVisibility != value)
                {
                    _adminButtonsVisibility = value;
                    OnPropertyChanged("AdminButtonsVisibility");
                }
            }
        }

Answer 14

Thai, you really need to read and understand the thread before your post.  The question is:

How do I bind a stackpanel Visibility property to my list box item IsSelected property.  How are you going to do that without a converter?

Ali, The reason why you are getting that error is that you can't use binding in a setter property of a style in Silverlight 4:

http://social.msdn.microsoft.com/Forums/en-US/silverlightstart/thread/3b0f03e2-ab3e-4417-9134-91c3e47fee34#a94b9e56-df69-4633-89d8-b65dbdb51715

Although you can in Silverlight 5:

http://www.kunal-chowdhury.com/2011/05/binding-on-style-setter-in-silverlight.html

So maybe Haixia is running Silverlight 5.