Question

Does one Resource item can be used only for one element at the same time?
For instance:

[xaml]

<Window.Resources>
    <Image x:Key="DockImage" Source="ico/pin.gif"/>
    <Image x:Key="UndockImage" Source="ico/pinHorizontal.gif"/>
</Window.Resources>

and buttons:

<Button Width="26" Name="solutionButton" Click="eventname">
       <DynamicResource ResourceKey="DockImage"/>
 </Button>
<Button Width="26" Name="soundButton" Click="eventname2">
       <DynamicResource ResourceKey="DockImage"/>
 </Button>

Their images changes to UndockImage on runtime, but Image is showed only on one of these buttons.
I can multiply Image keys for both DockImage and UndockImage but I assume this will take 2x more memory. Does one resource key can be used for one object (at the same time) ?

Answer 1

Anything deriving from UIElement can only be shown at one place at a time. You shouldn’t define Image resources directly, which is the control used to show images. Instead, use some ImageSource-derived class, such as BitmapImage, which represents an image in memory.

<Window.Resources>
  <BitmapImage x:Key="DockImage" UriSource="ico/pin.gif"/>
  <BitmapImage x:Key="UndockImage" UriSource="ico/pinHorizontal.gif"/>
</Window.Resources>

<Button Width="26" Name="solutionButton" Click="eventname">
  <Image Source="{StaticResource DockImage}"/>
</Button>
<Button Width="26" Name="soundButton" Click="eventname2">
  <Image Source="{StaticResource DockImage}"/>
</Button>