CODEWITHSUNDEEP
c#windows-phone-8visual-studio-2013listboxvisibility
Milky
Milky

Reputation: 73

Make visibility of listbox items to be visible when clicked on a button

XAML:

 <ListBox Height="163" HorizontalAlignment="Left" Margin="0,-24,0,0" Name="listBox2" VerticalAlignment="Top" Width="446" SelectedValuePath="" SelectionChanged="listBox2_SelectionChanged" >
                    <ListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Vertical">
                                <TextBlock x:Name="LblPassword" HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding RegistPassword}" VerticalAlignment="Top" Visibility="Collapsed" Foreground="Black"/>
                                <TextBlock x:Name="LblSecQn" HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding SecurityQn}" VerticalAlignment="Top" Margin="10,50,0,0" Visibility="Visible" Foreground="Black"/>
                                <TextBlock x:Name="LblSecAns" HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding SecurityAns}" VerticalAlignment="Top" Visibility="Collapsed" Foreground="Black"/>
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <TextBlock x:Name="LblEmail" Text="" HorizontalAlignment="Left" Margin="24,59,0,0" TextWrapping="Wrap" Foreground="Black" FontSize="30" VerticalAlignment="Top" Visibility="Collapsed"/>
                <Button x:Name="BtnSubmit" Content="Submit" HorizontalAlignment="Left" Margin="116,316,0,0" VerticalAlignment="Top" Height="88" Width="193" Click="BtnSubmit_Click" Foreground="Black" BorderBrush="Black"/>

.CS:

 private void BtnSubmit_Click(object sender, RoutedEventArgs e)
        {
       ListBoxItem listBoxItem = listBox2.SelectedItem as ListBoxItem;

            DataTemplate listBoxTemplate = listBoxItem.ContentTemplate;

            StackPanel outerStackPanel = listBoxTemplate.content as StackPanel;

            StackPanel innerStackPanel = outerStackPanel.Children[1] as StackPanel;

            TextBlock nameBox = innerStackPanel.Children[2] as TextBlock;
            nameBox.Visibility = Visibility.Visible;

    }

This is my currently my BtnSubmit_click. However,there is some exception on the listBoxTemplate.content part.

I want to make Visibility of LblSecAns to be visible when i clicked on BtnSubmit. I searched ans on google. It is telling me to use Visual tree helper. But i doesn't understand and doesn't know how to apply.

Upvotes: 0

Views: 793

Answers (1)

George Nikolaides
George Nikolaides

Reputation: 1386

There are two ways to achieve what you want to do here, if I understood correctly.

The first one is like you mentioned with the Visual Tree Helper. Basically every element with a Name, x:Name can be "accessed" using the command: var nameBox = GetTemplateChild("LblSecAns") as TextBox;.

I haven't specifically tested this code on your example (retrieve something from ItemTemplate) but it should work.

The other way and the best one from my point of View is to create a converter. I have been using converters for many reasons, including item's visibility so far and it makes things simpler while keeping the code clean.

A visibility converter would be like:

public class VisibilityConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return (bool)value) ? Visibility.Collapsed : Visibility.Visible;
    }

    public object ConvertBack(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        return Visibility.Visible;
    }
}

Then your TextBlock would change to:

<TextBlock x:Name="LblSecAns" HorizontalAlignment="Left" TextWrapping="Wrap" Text="{Binding SecurityAns}" VerticalAlignment="Top" Visibility="{Binding notAnswered, Converter={StaticResource VisibilityConverter}}" Foreground="Black"/>

And finally your button onClick method will simply be:

private void BtnSubmit_Click(object sender, RoutedEventArgs e)
    {
        ListBoxItem listBoxItem = listBox2.SelectedItem as <<ClassOfTheItem>>;

        listBoxItem.notAnswered = false;
}

Don't forget to add the notAnswered property to the item's class <<ClassOfTheItem>> you are binding the listbox to. Since I don't have your code I suggested adding a new property but this step might not be necessary since Visibility can be binded to something else, i.e. the actual answer.

Upvotes: 1

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