Question

How can I access a Canvas control, stored in DataTemplate of GridView items from my C# code?

<DataTemplate x:Key="250x250ItemTemplate">
    <Grid HorizontalAlignment="Left" Width="250" Height="250">
        <Border Background="{StaticResource ListViewItemPlaceholderBackgroundThemeBrush}">
            <Canvas x:Name="Canv"/>  <------ I WANT ACCESS THIS CANVAS FROM C# CODE
        </Border>
    </Grid>
</DataTemplate>
<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
    <GridView x:Name="GridViewData" ItemTemplate="{StaticResource 250x250ItemTemplate}"/>
</Grid>

I’m filling GridViewData items from C# code, setting GridViewData.ItemsSource with data from remotely loaded XML.

Then I need to modify Canvas (by adding children to it) of each element separately.

But I don’t understand how can I do that.

Can anyone help me with it?
Thank you in advance!

Answer 1

Everyone who interested in answering this question!
I’ve found a solution here: http://www.wiredprairie.us/blog/index.php/archives/1730

It’s horrible that I don’t understand why we need to do so much magic here, but it works.

namespace Extension
{
    public static class FrameworkElementExtensions
    {
        public static FrameworkElement FindDescendantByName(this FrameworkElement element, string name)
        {
            if (element == null || string.IsNullOrWhiteSpace(name))
            {
                return null;
            }
            if (name.Equals(element.Name, StringComparison.OrdinalIgnoreCase))
            {
                return element;
            }
            var childCount = VisualTreeHelper.GetChildrenCount(element);
            for (int i = 0; i < childCount; i++)
            {
                var result = (VisualTreeHelper.GetChild(element, i) as FrameworkElement).FindDescendantByName(name);
                if (result != null)
                {
                    return result;
                }
            }
            return null;
        }
    }
}

and

for (int i = 0; i<GridViewTickers.Items.Count; i++)
{
    var element = GridViewTickers.ItemContainerGenerator.ContainerFromIndex(i) as FrameworkElement;
    if (element != null)
    {
        var tb = element.FindDescendantByName("Canv") as Canvas;
        if (tb != null)
        {
            TextBlock tb1 = new TextBlock();
            tb1.Text = "hello";
            tb.Children.Add(tb1);
        }
    }
}

If anyone can explain for me what we’re doing in this bunch of code – please do this, ’cause my brain is exploding right now 🙂

Thank you all!