Vista - How to bind a Trigger to a user defined DependencyProperty

Hi

I do the following inside my code

public partial class ShoppingCart : StackPanel, INotifyPropertyChanged
{
public ShoppingCart()
{
InitializeComponent();
}


public static readonly DependencyProperty StatusProperty =
DependencyProperty.Register("Status", typeof(string),
typeof(ShoppingCart), new PropertyMetadata("unset"));

// You must provide CLR accessors for your property
public string Status
{
get { return (string)GetValue(StatusProperty); }
set
{
SetValue(StatusProperty, value);
HandlePropertyChanged("Status");
}
}


Inside the XAML I have something like

<StackPanel x:Class="AlpineWebApplication.ShoppingCart"
xmlns="http://schemas.microsoft.com/winfx/avalon/2005"
xmlns:x="http://schemas.microsoft.com/winfx/xaml/2005"
Orientation="Horizontal"
xmlns:System="System"
xmlns:Microsoft_Windows_Themes="Microsoft_Windows_Themes"
Width="15" ClipToBounds="True"
xmlns:d="http://schemas.microsoft.com/expression/interactivedesigner/2005"
xmlns:c="http://schemas.microsoft.com/winfx/2005/06/markup-compatibility"
c:Ignorable="d"
x:Name="ShoppingCartControl"
>
<StackPanel.Triggers>
<Trigger Property="ShoppingCart.Status" Value="Expand"
SourceName="ShoppingCartControl">
<Trigger.EnterActions>
<BeginStoryboard Storyboard="{StaticResource ExpandCart}"
x:Name="ExpandCart_BeginStoryboard"/>
</Trigger.EnterActions>
</Trigger>
....


However, when I execute all the above, I get this nice error message
which, unfortunately, means nothing to me:

Error at element 'Trigger' in markup file 'shoppingcart.xaml' : The
string 'ShoppingCart.Status' could not be set on the 'Property' property
which is of type 'DependencyProperty'. Please see the sdk documentation
for the Property property and the DependencyProperty class for an
explanation of allowable values..

I also tried to only use 'Status', "{Binding Path=Status}" for the
Property value and it didn't help.

Please enlighten me.

Thanks

Phil

You have to define a xmlns namespace for your "AlpineWebApplication"
project.

Add the following declaration to your root element attributes:

xmlns:local="clr-namespace=AlpineWebApplication"

and then, when declaring your trigger, you could do the following:

<Trigger Property="local:ShoppingCart.Status" Value="Expand">

While I did not try this particular solution myself, I encountered
similar problems and resolved it using the xmlns for my current
project...

the "SourceName" element is usefull when you want to declare a Trigger
on another element property... (e.g. if you have a child element and
want to trigger on one of its property)...

Try this and let me know if it solved your issue..

Bonne chance!!!

Marcus

Philippe Lavoie wrote:
> Hi
>
> I do the following inside my code
>
> public partial class ShoppingCart : StackPanel, INotifyPropertyChanged
> {
> public ShoppingCart()
> {
> InitializeComponent();
> }
>
>
> public static readonly DependencyProperty StatusProperty =
> DependencyProperty.Register("Status", typeof(string),
> typeof(ShoppingCart), new PropertyMetadata("unset"));
>
> // You must provide CLR accessors for your property
> public string Status
> {
> get { return (string)GetValue(StatusProperty); }
> set
> {
> SetValue(StatusProperty, value);
> HandlePropertyChanged("Status");
> }
> }
>
>
> Inside the XAML I have something like
>
> <StackPanel x:Class="AlpineWebApplication.ShoppingCart"
> xmlns="http://schemas.microsoft.com/winfx/avalon/2005"
> xmlns:x="http://schemas.microsoft.com/winfx/xaml/2005"
> Orientation="Horizontal"
> xmlns:System="System"
> xmlns:Microsoft_Windows_Themes="Microsoft_Windows_Themes"
> Width="15" ClipToBounds="True"
> xmlns:d="http://schemas.microsoft.com/expression/interactivedesigner/2005"
> xmlns:c="http://schemas.microsoft.com/winfx/2005/06/markup-compatibility"
> c:Ignorable="d"
> x:Name="ShoppingCartControl"
> >
> <StackPanel.Triggers>
> <Trigger Property="ShoppingCart.Status" Value="Expand"
> SourceName="ShoppingCartControl">
> <Trigger.EnterActions>
> <BeginStoryboard Storyboard="{StaticResource ExpandCart}"
> x:Name="ExpandCart_BeginStoryboard"/>
> </Trigger.EnterActions>
> </Trigger>
> ...
>
>
> However, when I execute all the above, I get this nice error message
> which, unfortunately, means nothing to me:
>
> Error at element 'Trigger' in markup file 'shoppingcart.xaml' : The
> string 'ShoppingCart.Status' could not be set on the 'Property' property
> which is of type 'DependencyProperty'. Please see the sdk documentation
> for the Property property and the DependencyProperty class for an
> explanation of allowable values..
>
> I also tried to only use 'Status', "{Binding Path=Status}" for the
> Property value and it didn't help.
>
> Please enlighten me.
>
> Thanks
>
> Phil