Vista - How to add handler or listen to a change of dependency property

Dear all

I want to implement "BitmapButton" derived from Button
BitmapButtons have 4 images for each state(normal, pressed, disabled,
and mouseOver)

It's proper to use ControlTemplate to customize and add Triggers.
But I can't use TemplateBinding in Triggers' Setter
( I need to template binding a dependency property in MouseOver trigger
i.e. change image source)

So I find other way to do that.
I want to listen the UIElement.IsMouseOver property change?
And write code to change bitmap.

firstly, I use DependencyProperty.OverrideMetadata to new a metadata
with my PropertyChangedCallback.
But I got a exception which says that I have no authroization key to
override.

does anyone know how to implement it?
Thanks :-)

Maybe you can use OnMouseEnter/Leave events?
--
Valentin Iliescu [MVP - Client Application Development]


"HolaMan" wrote:

> Dear all
>
> I want to implement "BitmapButton" derived from Button
> BitmapButtons have 4 images for each state(normal, pressed, disabled,
> and mouseOver)
>
> It's proper to use ControlTemplate to customize and add Triggers.
> But I can't use TemplateBinding in Triggers' Setter
> ( I need to template binding a dependency property in MouseOver trigger
> i.e. change image source)
>
> So I find other way to do that.
> I want to listen the UIElement.IsMouseOver property change?
> And write code to change bitmap.
>
> firstly, I use DependencyProperty.OverrideMetadata to new a metadata
> with my PropertyChangedCallback.
> But I got a exception which says that I have no authroization key to
> override.
>
> does anyone know how to implement it?
> Thanks :-)
>
>

Dear villiescu

Thanks for your reply.
Indeed I have used this method and it works.

But I just curious about the trigger mechanism and want to make code
shorter and easier
:-) Thanks

you could try adding a DataTrigger in your ControlTemplate`s
Triggers...

<ControlTemplate>
<ControlTemplate.Triggers>
<DataTrigger Binding={IsMouseOver}
Value="True">
<Setter TargetName="MyImage"
Property="Source"
Value="{StaticResource MouseOverImage}" />
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>


I have used DataTriggers a large number of times.... (Although not in
this particular one) and it made the job for me...

HTH

Marcus

Thanks you very much, Marcus
I will try it

While re-reading the thread... I noticed an error in my own post...

the Binding member of the DataTrigger should have been "{Binding
IsMouseOver}"...

Hope this did not cause any confusion!!!

You cannot use TemplateBinding in the Triggers' Setter but can you try to use
Binding
like this to see if it works:
<Setter TargetName="myImage" Property="Source"
Value="{Binding Path=MouseOverImageSource,RelativeSource={RelativeSource
TemplatedParent}}" />
--
Valentin Iliescu [MVP - Client Application Development]


"HolaMan" wrote:

> Dear all
>
> I want to implement "BitmapButton" derived from Button
> BitmapButtons have 4 images for each state(normal, pressed, disabled,
> and mouseOver)
>
> It's proper to use ControlTemplate to customize and add Triggers.
> But I can't use TemplateBinding in Triggers' Setter
> ( I need to template binding a dependency property in MouseOver trigger
> i.e. change image source)
>
> So I find other way to do that.
> I want to listen the UIElement.IsMouseOver property change?
> And write code to change bitmap.
>
> firstly, I use DependencyProperty.OverrideMetadata to new a metadata
> with my PropertyChangedCallback.
> But I got a exception which says that I have no authroization key to
> override.
>
> does anyone know how to implement it?
> Thanks :-)
>
>

Sorry, instead of TemplatedParent should be Self.

<Setter TargetName="myImage" Property="Source"
Value="{Binding Path=MouseOverImageSource,RelativeSource={RelativeSource
Self}}" />

--
Valentin Iliescu [MVP - Client Application Development]


"HolaMan" wrote:

> Dear all
>
> I want to implement "BitmapButton" derived from Button
> BitmapButtons have 4 images for each state(normal, pressed, disabled,
> and mouseOver)
>
> It's proper to use ControlTemplate to customize and add Triggers.
> But I can't use TemplateBinding in Triggers' Setter
> ( I need to template binding a dependency property in MouseOver trigger
> i.e. change image source)
>
> So I find other way to do that.
> I want to listen the UIElement.IsMouseOver property change?
> And write code to change bitmap.
>
> firstly, I use DependencyProperty.OverrideMetadata to new a metadata
> with my PropertyChangedCallback.
> But I got a exception which says that I have no authroization key to
> override.
>
> does anyone know how to implement it?
> Thanks :-)
>
>

Dear viliescu

I have use Self or TemplatedParent
and TemplatedParent works.

Thanks you very much.

Dear viliescu

I have used Self or TemplatedParent
and TemplatedParent works.

Thanks you very much.