How to enable the SelectionChanged event on specific button click in Listbox in windows phone 7?

Question

I am developing window phone 7 application in C#. I am new to the window phone 7 application. I am also new to the silverlight. I have taken the ListBox control in my xaml file & adding the many button controls to this listbox control dynamically. My xaml code is as follows

<phone:PhoneApplicationPage 
    x:Class="ExpenseMgrMobAppl.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="Expnse Manager" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="Entry Details" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0"> 

            <toolkit:DatePicker Name="EntryDate" ValueChanged="DatePicker_ValueChanged" Margin="267,0,0,552" />

            <ListBox x:Name="lstButtons" Margin="358,61,10,31" SelectionChanged="lstButtons_SelectionChanged" Width="80" Height="500">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <Button Content="{Binding ElementName}" Width="50" HorizontalAlignment="Center"></Button>
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

            <Button Content="Add" Height="72" HorizontalAlignment="Left" Margin="107,504,0,0" Name="Addbutton" VerticalAlignment="Top" Width="160" Click="Addbutton_Click" />
        </Grid>
    </Grid>

    <!--Sample code showing usage of ApplicationBar-->
    <!--<phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>
                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>

In the above code everything is working file. Only the problem is that I am not able fire the method SelectionChanged="lstButtons_SelectionChanged" . I am able to fire this method by clicking on the edge of area of the listbox control. When I click on the middle of the square of the button, the method does not fire. But when I click outside the area of the square of the button (the area which is in the right direction of the button & that area is near the edge of the area of listbox control) the method gets fired. This is I think because I am not clicking on the right area. I think I am not able to specify the right are for button click in my code & thats why the event is not firing.

I have another example of similar type where everything is working fine & event is also firing properly. The xaml for this example is as follows

<phone:PhoneApplicationPage 
    x:Class="WindowsPhoneNavigation.Views.Pictures.Default"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock Text="{StaticResource AppName}" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock Text="Images" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <StackPanel Orientation="Vertical">
                <StackPanel Orientation="Horizontal" Margin="5">
                    <Button x:Name="btnRemoveSelection" Content="Remove Image" Click="btnRemoveSelection_Click" IsEnabled="False"/>
                </StackPanel>

                <ListBox x:Name="lstPictures" Width="450" Height="520" Margin="10" SelectionChanged="lstPictures_SelectionChanged">
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <Image Source="{Binding Image}" Width="100" Stretch="Uniform" HorizontalAlignment="Center"/>
                                <TextBlock Text="{Binding Filename}" TextWrapping="Wrap" />
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
            </StackPanel>
        </Grid>
    </Grid>

    <!--Sample code showing usage of ApplicationBar-->
    <!--<phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>
                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>

Can you please tell me where I am going wrong in the first case described above ? Can you please provide me any code or link through which I can resolve the above issue. What modifcation should I done in my code for the first case described above so that when I click on exactly in the square of the button area the event SelectionChanged="lstButtons_SelectionChanged" gets fired ?

Answer 1

What is probably happening is that the Button is handling the click event by default and thus not allowing it to propagate to the ListBox . I'm assuming your intent is to access the data object associated with the row containing the button that you clicked on. In that case you can add a button click handler and use the following:

void Button_Click(object sender, RoutedEventArgs e)
{
  Button b = sender as Button;  // sender is the button user clicked
  MyDataObject data = b.DataContext as MyDataObject;  // data is the MyDataObject for that row
  // ...
}

Your second example works because neither TextBlock nor Image are intercepting the click event before it gets to the ListBox SelectionChanged handler.