topic Re: Window Panel Problem in ArcGIS API for Silverlight Questions

Window Panel Problem

AnilDhiman — Mon, 17 May 2010 08:46:34 GMT

Arcgis silverlight template comes with a Window panel control. I have placed a user control which takes Map as dependency property. Now, I need this Window panel to collapse on Load. I tried Visibility=Collapsed in XAML and it worked but now My dependency property is not firing.

Is this a bug with Window Panel? or is there any other method to do so

Re: Window Panel Problem

DominiqueBroux — Sat, 11 Dec 2021 09:14:43 GMT

As your control is not visible, it's not loaded.
You might try by making it visible and by collapsing it when loaded.
Example in XAML:

            <i:Interaction.Triggers>
                <i:EventTrigger EventName="Loaded">
                    <ei:ChangePropertyAction PropertyName="Visibility">
                        <ei:ChangePropertyAction.Value>
                            <Visibility>Collapsed</Visibility>
                        </ei:ChangePropertyAction.Value>
                    </ei:ChangePropertyAction>
                </i:EventTrigger>
            </i:Interaction.Triggers>

Re: Window Panel Problem

AnilDhiman — Wed, 19 May 2010 07:49:30 GMT

I tried this but still depency property is not firing. any suggestions?

Re: Window Panel Problem

DominiqueBroux — Sat, 11 Dec 2021 09:14:45 GMT

I did some additional tests and I was able to reproduce the issue when the DP is initialized with a binding. Is it your case?

In this case, the DP is initialized after the Loaded event (if the control is visible), and so if the loaded event put the visibility to collapsed, the DP is not initialized.
This behavior doesn't look tie to the Window Panel but more general to the Loaded event with Silverlight.

I found an article (http://bryantlikes.com/FakingTheInitializedEventInSilverlight.aspx) which is suggesting to use the dispatcher in the constructor.
If we change the visibility this way, the DP are initialized (in the cases I tested...)

public MainPage()
{
 InitializeComponent();
 Dispatcher.BeginInvoke(Initialized);
}

private void Initialized()
{
 MyControl.Visibility = Visibility.Collapsed;
}

Note that another workaround could be you to change the Opacity instead of the Visibility. Keep your control visible but with an opacity of 0. So the DP are initialized and when your control is ready, you can set the opacity to 1.0.

Re: Window Panel Problem

AnilDhiman — Wed, 19 May 2010 12:17:11 GMT

Thanks for your suggestions, I did a similar workaround by changing the margin of control to out of screen and on click of button again changed the margin as desired.

but the first approach looks pretty good. I will try that, thanks