WPF Discussion Boards

Re: WPF Binding to an attached property from a DataTemplate

14-Nov-08 13:13

Is there a good way to bind an element created through a DataTemplate to
an attached property?

Please refer to this post[^] for full source code
(scroll down to around the smiley)...

Elements are created through a DataTemplate and end up as children of a Grid.

The data has Row and Col properties that need to be bound to the Grids Row and
Column attached properties.

The most obvious binding (to me) would be something like this:

<DataTemplate DataType="{x:Type local:Obs}">
    <Button <code>Grid.Row="{Binding Path=Row}" Grid.Column="{Binding Path=Col}"</code> Click="Button_Click">
        <Button.Style>
            <Style TargetType="{x:Type Button}" >
                <Setter Property="Content" Value="{Binding Path=Name}"/>
                <Setter Property="Width" Value="50"/>
                <Setter Property="Height" Value="Auto"/>
                <Setter Property="Margin" Value="2"/>
                <Setter Property="Background" Value="#FFBBBB00"/>
                <Setter Property="Foreground" Value="#FF000000"/>
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Path=Status}" Value="On">
                        <Setter Property="Background" Value="#FFFFFF00"/>
                        <Setter Property="Foreground" Value="#FFFF0000"/>
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </Button.Style>
    </Button>
</DataTemplate>

but it doesn't work, I assume because the element isn't yet a child
of the grid at the time the binding is created.

Based on that assumption, I figured I needed an event of some kind to give me a chance to
do the binding once the created element is a child of the grid.

As seen in the code, my workaround was to override ArrangeOverride() on the Grid
and programatically create the binding there. That works, but I hate it Smile | :)

Is there a better way?

I'd love to do it completely in XAML, but I'm not smart enough yet.

Thanks!
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Friday, November 14, 2008 7:23 PM

Timmy Kokke14-Nov-08 13:46

Timmy Kokke

14-Nov-08 13:46

Inside a datatemplate you can bind to a relative source, a parent, of the object by using the RelativeSource attribute.

You should try and experiment with something like:

<DataTemplate DataType="{x:Type local:Obs}">      
     <Button Grid.Row="{Binding Path=Row, RelativeSource={RelativeSource AncestorType={x:Type Grid}}}" 
             Grid.Column="{Binding Path=Col, RelativeSource={RelativeSource AncestorType={x:Type Grid}}}" 
             Click="Button_Click">
..

Good Luck!

Dawn is nature's way of telling you to go to bed.

Re: WPF Binding to an attached property from a DataTemplate

Mark Salsbery14-Nov-08 14:20

Re: WPF Binding to an attached property from a DataTemplate

14-Nov-08 14:20

I've experimented for HOURS on this Smile | :)

Anyway, that doesn't work in the context of the code I linked to
(a DataTemplate for an ItemsControl ItemsTemplate)...tried it already,
and tried it again.

I do appreciate the help, thanks!

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Timmy Kokke14-Nov-08 22:10

Timmy Kokke

14-Nov-08 22:10

My fault... I misread your post, I guess I was working a bit too late... Sleepy | :zzz:

Anyway, I just recreated a solution based on your code in a previous post. I do not entirely understand what you're trying to do... When I click the Test button, button 3 moves to the first column and a 6th button is added to the grid. Like this:Screenshot[^].

Is this what is supposed to happen? If not, could you explain a bit more about what should happen.

Dawn is nature's way of telling you to go to bed.

Re: WPF Binding to an attached property from a DataTemplate [modified]

Mark Salsbery15-Nov-08 5:36

Re: WPF Binding to an attached property from a DataTemplate

15-Nov-08 5:36

Timmy Kokke wrote:
Is this what is supposed to happen?

Yes

I was demonstrating to the OP how changing the data would reflect
in the UI - the test showed you can change the cell position of existing
objects in the collection and add items to the collection.

The code I posted works like I wanted it to....I just didn't like the way
I did the binding from the data object's Row and Col properties to the
Grid.Row and Grid.Column attached properties, and I could't figure out
a better way, so I started this new thread.

Cheers,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Saturday, November 15, 2008 12:51 PM

Gideon Engelberth14-Nov-08 16:48

Gideon Engelberth

14-Nov-08 16:48

The reason why this does not work is because the ItemsControl wraps your object in a container. To get the binding you want you will need to make an StyleSelector to assign to the ItemContainerStyleSelector property of the Items control. Something like this should work:

Public Overrides Function SelectStyle(ByVal item As Object, 
                                      ByVal container As System.Windows.DependencyObject)
                                      As System.Windows.Style
    Dim matElem As Obs = TryCast(item, Obs)

    Dim ret As New Style()
    If matElem IsNot Nothing Then
        ret.Setters.Add(New Setter(Grid.RowProperty, matElem.PositionY))
        ret.Setters.Add(New Setter(Grid.ColumnProperty, matElem.PositionX))
    End If

    Return ret
End Function

Re: WPF Binding to an attached property from a DataTemplate

Mark Salsbery15-Nov-08 6:40

15-Nov-08 6:40

Excellent Gideon, thank you!

StyleSelector is news to me Smile | :)

I actually needed bindings, not just setters for the initial value, but I'm
much more comfortable setting them in the item style selector than in the
grid ArrangeOverride like I was doing in my hacked solution. This is a much
more appropriate place to set the bindings and I was able to remove the silly
IsBoundToUI flag from the data object class.

Here's what I did:

public class ObsItemStyleSelector : StyleSelector
{
    public override Style SelectStyle(object item, DependencyObject container)
    {
        Obs obs = item as Obs;
        ContentPresenter cp = container as ContentPresenter;

        if (null != obs && null != cp)
        {
            Binding binding = new Binding("Row");
            binding.Source = obs;
            cp.SetBinding(Grid.RowProperty, binding);

            binding = new Binding("Col");
            binding.Source = obs;
            cp.SetBinding(Grid.ColumnProperty, binding);
        }

        return null;
    }
}

That works well!

Thanks again,
Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

SWF Player in WPF

ctrlnick14-Nov-08 10:25

ctrlnick

14-Nov-08 10:25

Can someone tell me how to play an swf file via WPF?

Please I need it asap

Thanks

Happy Programming!

Regards,
ctrlnick !

Re: SWF Player in WPF

Pete O'Hanlon14-Nov-08 10:32

14-Nov-08 10:32

You need to embed the flash player in your WPF application. You'd use the WindowsFormsHost to put the control in - and you'd have to wrap the ActiveX control.

Deja View - the feeling that you've seen this post before.

Do we have a something like MASK effect (in SwishMax or Flash) in WPF?

Re: SWF Player in WPF

ctrlnick14-Nov-08 10:54

ctrlnick

14-Nov-08 10:54

I tried, Can you show me sample code?

Happy Programming!

Regards,
ctrlnick !

Mohammad Dayyan14-Nov-08 10:14

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

14-Nov-08 10:14

Hi guys.
Do we have a sth like MASK effect (in SwishMax or Flash) in WPF ?
For seeing the MASK effect take a look at this flash
http://www.swishzone.com/products/max_mini/demos/swf/mask_example.html[^]
Thanks

modified on Friday, November 14, 2008 4:49 PM

Pete O'Hanlon14-Nov-08 10:43

14-Nov-08 10:43

What's an sth like MASK?

Deja View - the feeling that you've seen this post before.

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

Mohammad Dayyan14-Nov-08 10:48

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

14-Nov-08 10:48

Sorry for my English, I'm new.
My purpose has been `something like MASK`
For seeing MASK effect take a look at this flash http://www.swishzone.com/products/max_mini/demos/swf/mask_example.html[^]

Pete O'Hanlon14-Nov-08 11:04

14-Nov-08 11:04

I'd use the 3D features of WPF to do this - it will look much better. I'm a little bit busy with the WPF folder browser, so I don't really have time to knock up an implementation right now but if you can wait until next week I'll get back to you on this one.

Deja View - the feeling that you've seen this post before.

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

Mohammad Dayyan14-Nov-08 11:08

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

14-Nov-08 11:08

OK, thanks .
I'm waiting

Pete O'Hanlon14-Nov-08 11:10

14-Nov-08 11:10

Geez. What's with you guys and all the pressure? Wink | ;)

Only kidding.

Deja View - the feeling that you've seen this post before.

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

Mark Salsbery15-Nov-08 7:02

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

15-Nov-08 7:02

A little less chit-chatting and a little more work Pete! Poke tongue | ;-P

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Pete O'Hanlon15-Nov-08 8:52

15-Nov-08 8:52

Sorry - but I was cranking out code at 10 past 1 this morning, so I feel properly self-righteous.

Deja View - the feeling that you've seen this post before.

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

Mark Salsbery15-Nov-08 9:05

Re: Do we have sth like MASK effect (in SwishMax or Flash) in WPF?

15-Nov-08 9:05

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

lneir14-Nov-08 15:07

lneir

14-Nov-08 15:07

Here is some xaml that will animate an ellipse across the text...basically using visual brush to set the fill property of a TextBlock. Then I animate the Left and Top property of ellipse contained in the visual brush. Since a visual brush can be anything you could put image or video here also, basically any visual you want. Enjoy...

<Window x:Class="TextClippingSomething.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="500">
<Window.Resources>
<Storyboard x:Key="Storyboard1" RepeatBehavior="Forever" AutoReverse="True">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:03" Storyboard.TargetName="MyEllipse" Storyboard.TargetProperty="(Canvas.Left)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="0"/>
<SplineDoubleKeyFrame KeyTime="00:00:03" Value="100"/>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Duration="00:00:03" Storyboard.TargetName="MyEllipse" Storyboard.TargetProperty="(Canvas.Top)">
<SplineDoubleKeyFrame KeyTime="00:00:00" Value="20"/>
<SplineDoubleKeyFrame KeyTime="00:00:01" Value="15"/>
<SplineDoubleKeyFrame KeyTime="00:00:02" Value="20"/>
<SplineDoubleKeyFrame KeyTime="00:00:01" Value="15"/>
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</Window.Resources>
<Window.Triggers>
<EventTrigger RoutedEvent="FrameworkElement.Loaded">
<BeginStoryboard Storyboard="{StaticResource Storyboard1}"/>
</EventTrigger>
</Window.Triggers>
<Grid>
<TextBlock Text="This is my Text" FontSize="60" FontWeight="Black" RenderTransformOrigin="0.5,0.5" x:Name="textBlock">
<TextBlock.Foreground>
<VisualBrush Stretch="UniformToFill">
<VisualBrush.Visual>
<Canvas>
<Rectangle Width="100" Height="50" Fill="Red"/>
<Ellipse x:Name="MyEllipse" Canvas.Left="0" Canvas.Top="20" Height="10" Width="10" Fill="Aqua"/>
</Canvas>
</VisualBrush.Visual>
</VisualBrush>
</TextBlock.Foreground>
</TextBlock>
</Grid>
</Window>

Changing button states ?

Mohammad Dayyan14-Nov-08 9:07