Question

I have an ItemTemplate that contains a simple button. When I click this button I need a way to identify the row clicked to pull out the item bound to the listbox.

XAML

        <ListBox Name="DemoBox" SelectionChanged="listBox_SelectionChanged">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <Grid Height="150">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="400"/>
                            <ColumnDefinition/>
                        </Grid.ColumnDefinitions>
                        <Grid Height="120" Grid.Column="0">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="60"/>
                            </Grid.RowDefinitions>
                            <TextBlock
                                    Grid.Row="0"
                                    Text="{Binding SomeObjProperty}"/>
                        </Grid>
                        <Grid Height="120" Grid.Column="1" Margin="0,-12,0,0">
                            <Button Click="ShowStuffOnMap_Click">
                                <Button.Background>
                                    <ImageBrush ImageSource="images/arrow.png"/>
                                </Button.Background>
                            </Button>
                        </Grid>
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

click handler

    private void ShowStuffOnMap_Click(object sender, RoutedEventArgs e)
    {
        //sender is the button so ...
    }

Thank you in advance

Answer 1

Why do you have Button with a click event inside a ListBox with a SelectionChanged event? This makes up for some scary UX, if they have different actions!

The normal approach is to have a databound ListBox, and then use the SelectionChanged event to read out the selected item.

private void ListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    var listBox = sender as ListBox;
    var selectedItem = listBox.SelectedItem as MyDataBoundType;

    if (selectedItem != null)
    {
        // do stuff
    }

    // if you use the ListBox for navigation, set the SelectedIndex to -1
    // listBox.SelectedIndex = -1;
}

But if you really really want to do it, you need to use the Tag property.

<Button Click="ShowStuffOnMap_Click" Tag="{Binding}">

And then in your event handler:

private void ShowStuffOnMap_Click(object sender, RoutedEventArgs e)
{
    var button = sender as Button;
    var selectedItem = button.Tag as MyDataBoundType;
}

But I still think your approach here is wrong, and stands for bad user experience, as the normal approach to a list is that the entire line in the list, is one-selection only.