UWP define resource dictionary KVP globally - wpf

Say I wanted to define <SolidColorBrush x:Key="TabViewItemHeaderBackgroundSelected" Color="#ffffff" /> globally.
Note: this is a custom key for a TabView https://learn.microsoft.com/en-us/windows/communitytoolkit/controls/tabview
When I define this in App.Xaml it does not reach any of my TabViews.
When I define this in a Page, it only reaches some of my TabViews, it fails to reached heavily nested ones.
I believe this could be achieved through merged dictionaries. However, referencing a merged dictionary for each of these scopes is not very clean. And the way dictionaries are references in the source property is not very clean either.
The only think I have though of so far is creating a custom component which inherits TabView and defines the resource KVPs. Then I just need to reference the new component. I still think declaring globally would be cleaner, is this possible?

UWP define resource dictionary KVP globally
Thanks for your interesting, for this scenario, the better way is custom TabView and edit the default TabViewItemHeaderBackgroundSelected within the default style. And you could find the default style here.

Related

Can the WPF ResourceDictionary return a new instance for each request

We're using ResourceDictionaries to store layout information for our app. The lazy initialisation is great because we can grab the required layout for an element only when that element is created. The problem is that each element gets the same instance from the ResourceDictionary for each one that shares the layout (or the same one if it goes out of scope and is needed later).
We could store templates in the dictionary then it doesn't matter if they're shared but we have quite a nice system going if it wasn't for this caching behaviour.
Is there a way to change this behaviour of the dictionary or am I going to have to write my own class which creates items from the XAML on demand?
Try applying x:Shared="false" attribute. Each resource should then get seperate copy.

Overriding some theme styles and properties per module

I am writing a WPF application using "Prism", and some purchased Grid theme is applied "Xceed Theme." I am designing a huge change required by our customer to give them the option of modifying some properties (like the background of selected row, for example) and this functionality to be available per screen "Module."
So my questions are:
After adding my xceed grid theme source to my App.xaml merged dictionaries, how can I override some of its styles (that I know the keys of) in another xaml file away from app.xaml (possibly by adding BasedOn to the style tag)?
Is it possible to create a custom resource dictionary for each module and add it to the app.xaml merged dictionaries while loading?
You could add the style changes in the main window/control's resources within each module. Then the differences would apply to each module separately.
In my case, I have userd Dynamic Resources. The main project loads the main style. somthing like this :
<FontFamily x:Key="ApplicationFontFamily">Tahoma</FontFamily>
and in my module i have changed it programmatically :
Application.Current.Resources["ApplicationFontFamily"] = new FontFamily("Arial");
it worked for me ;)

please explain what is themes and generic.xaml? [duplicate]

I've been trying to figure out how to organize my ResourceDictionary files for reuse and sharing with other members of my team.
I keep coming across "Generic.xaml", but if I look on MSDN for Generic.xaml or just do a Google search, I only seem to get blog posts and forum questions that happen to mention it--I can't seem to hit upon anything really authoritative and clear.
What is the difference between Generic.xaml and MyRandomlyNamedResourceDictionary.xaml? It seems like either way, I have to reference ResourceDictionaries stored in libraries with the Source attribute. E.g.,:
<Application.Resources>
<ResourceDictionary
Source="/CommonLibraryWpfThemes;component/Themes/Generic.xaml"
</Application.Resources>
So what advantage does Generic.xaml provide exactly? Does it have any purpose if I'm not trying to give my application multiple "looks" (i.e., if I have only one theme)?
Every Control in WPF has a default Style that provides, among other things, the Control's default ControlTemplate. WPF looks for the default style in a special resource dictionary in the Themes folder in the same assembly as the control. The key for the default style is provided by the Control.DefaultStyleKey dependency property, the default value of which is overridden in each sub-class of Control.
The name of the resource dictionary depends on the current Windows theme e.g. on Vista using the Aero theme, the dictionary is called Aero.NormalColor.xaml, on XP using the default theme it is Luna.NormalColor.xaml. If the style is not found in the theme dictionary, it looks in Generic.xaml i.e for controls whose look doesn't depend on the theme.
This only applies to any custom controls you have defined i.e. classes derived from Control, directly or indirectly. You can change the default style for a standard control by deriving from it and calling DefaultStyleKeyProperty.OverrideMetadata in the static constructor, but you then have to supply the full style including ControlTemplate.
Note that you can tell WPF to look in an external assembly for your default style by using the ThemeInfo attribute. The external assembly must be named <YourAssembly>.<ThemeName>.dll e.g. PresententationFramework.Aero.dll.
For a generic.xaml file (case insensitive) to be something special, two conditions must be met:
It must be in the Themes sub-root folder in the project
The assembly must be marked with the ThemeInfoAttribute (usually in AssemblyInfo.cs)
Then it serves as the default lookup location for any default styles you wish to apply to your Controls. Note also that for a style to be the default it must declare both its TargetType and x:Key as the Type of Control which is to be styled.
If you wish to add entire themes and theme switching to your application, that is accomplished with some coding, this technique merely defines the default resource dictionary.

What is so special about Generic.xaml?

I've been trying to figure out how to organize my ResourceDictionary files for reuse and sharing with other members of my team.
I keep coming across "Generic.xaml", but if I look on MSDN for Generic.xaml or just do a Google search, I only seem to get blog posts and forum questions that happen to mention it--I can't seem to hit upon anything really authoritative and clear.
What is the difference between Generic.xaml and MyRandomlyNamedResourceDictionary.xaml? It seems like either way, I have to reference ResourceDictionaries stored in libraries with the Source attribute. E.g.,:
<Application.Resources>
<ResourceDictionary
Source="/CommonLibraryWpfThemes;component/Themes/Generic.xaml"
</Application.Resources>
So what advantage does Generic.xaml provide exactly? Does it have any purpose if I'm not trying to give my application multiple "looks" (i.e., if I have only one theme)?
Every Control in WPF has a default Style that provides, among other things, the Control's default ControlTemplate. WPF looks for the default style in a special resource dictionary in the Themes folder in the same assembly as the control. The key for the default style is provided by the Control.DefaultStyleKey dependency property, the default value of which is overridden in each sub-class of Control.
The name of the resource dictionary depends on the current Windows theme e.g. on Vista using the Aero theme, the dictionary is called Aero.NormalColor.xaml, on XP using the default theme it is Luna.NormalColor.xaml. If the style is not found in the theme dictionary, it looks in Generic.xaml i.e for controls whose look doesn't depend on the theme.
This only applies to any custom controls you have defined i.e. classes derived from Control, directly or indirectly. You can change the default style for a standard control by deriving from it and calling DefaultStyleKeyProperty.OverrideMetadata in the static constructor, but you then have to supply the full style including ControlTemplate.
Note that you can tell WPF to look in an external assembly for your default style by using the ThemeInfo attribute. The external assembly must be named <YourAssembly>.<ThemeName>.dll e.g. PresententationFramework.Aero.dll.
For a generic.xaml file (case insensitive) to be something special, two conditions must be met:
It must be in the Themes sub-root folder in the project
The assembly must be marked with the ThemeInfoAttribute (usually in AssemblyInfo.cs)
Then it serves as the default lookup location for any default styles you wish to apply to your Controls. Note also that for a style to be the default it must declare both its TargetType and x:Key as the Type of Control which is to be styled.
If you wish to add entire themes and theme switching to your application, that is accomplished with some coding, this technique merely defines the default resource dictionary.

How do you exclude an object from picking up the default Resource Dictionary?

I am using a 3rd party resource dictionary and it is conflicting with another usercontrol that I need to use. How do I exclude this usercontrol from picking up the default resource dictionary?
Thanks
Dave
dont know if you can explicity exclude it but you could create your own resource dictionary and create a style for your control within it.
Reference the style specifically with a key and use that key for you user control. Should override the default resource dictionary. You may have to merge resource dictionaries into a shared resource.

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