WP8 Change pivot header color (selected / unselected) - xaml

I need to change a pivot header color but still have a different color for selected and unselected pivot item headers.
I can easily change the color of all the headers but i really need a way to differentiate selected and unselected pivot items.
I have tried many ways to do this for windows phone 7 but the pivot header architecture seem to have changed and the styles no longer work.

I couldn't find a direct way of doing this by for example creating a new headertemplate, but you change this applicationwide by overriding the correct solidcolorbrushes in the theme dictionary. So in App.xaml:
<Application>
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Default">
<SolidColorBrush
x:Key="PivotHeaderForegroundUnselectedBrush"
Color="Purple"/>
<SolidColorBrush
x:Key="PivotHeaderForegroundSelectedBrush"
Color="Orange"/>
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
This is not a completely foolproof approach, it is explained in more detail at http://msdn.microsoft.com/library/windows/apps/br208807

Related

How can I change a style via code that is stored in a resource dictionary in App.xaml on the fly?

I am trying to have the ability for several core colors throughout the app to be changeable on the fly by the user. My current idea is to have a single SolidColorBrush that is my "theme color" and then to reference that throughout my main styles.
<SolidColorBrush x:Key="ReflectiveColor1" Color="#FF0E777B"></SolidColorBrush>
This snippet is stored in a resourcedictionary that is reference in my App.xaml
<Application.Resources>
<ResourceDictionary Source="DictionaryAlienwareTheme.xaml">
</ResourceDictionary>
</Application.Resources>
When I try and access the color in my App.cs I get an error
Application.Current.Resources["ReflectiveColor1"] = Colors.Black;
Error:
System.Runtime.InteropServices.COMException: 'No installed components were
detected.
Local values are not allowed in resource dictionary with Source set
Is there anyway to make this work? I'm assuming this error is because it doesn't want us to modify styles stored there, but I don't know the workaround.
Firstly, in your App.xaml if you want to reference the DictionaryAlienwareTheme.xaml you defined by yourself you need to merge the dictionaries to current app as #AVK said. More details please reference "Merged resource dictionaries" section of this article.
Secondly, after you use the merged resource, if you want to update the theme resource code behind you may need to use Application.Current.Resources.MergedDictionaries to visit the merged dictionaries instead of Application.Current.Resources. For example,
public MainPage()
{
this.InitializeComponent();
var mergedDict = Application.Current.Resources.MergedDictionaries.FirstOrDefault();
((SolidColorBrush)mergedDict["ReflectiveColor1"]).Color = Colors.Red;
}
By the way, as above code snippet showed, ReflectiveColor1 is SolidColorBrush you cannot set color directly.
Application will not be able to find the Resource ReflectiveColor1 until you merge all resource dictionaries together.
Change your App.xaml to Merge the dictionaries. Like below.
<Application.Resources>
<ResourceDictionary >
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="DictionaryAlienwareTheme.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
Then you should be able to access the Resource in the same way that you were doing before.

How to change the default style of a XAML control?

I want to change the default style or theme of the pivot control and I've found some really cool samples online, but i don't know where to place them in.
should i make a new file or edit an existing one?
You can create a new XAML ResourceDictionary in the project, where you can place these styles.
After that you have to include this resource dictionary as merged dictionary in the App.xaml:
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="ms-appx:///MyFolder/MyResourceDictionary.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
Of course you don't have to create seperate file for these resources, you can place these to any Resources collection. Like to the Application.Resources in App.xaml or to the Page.Resourcesin the page's xaml.
A style will be default to the target control, if you don't provide any x:Key="" to them in the resource collection. These are implicit styles.

Windows 10 XAML 'Theming' a Style

I want to make ComboBoxes in my Windows 10 App to have theme colours (One have a green theme, one with an orange theme...etc). I can do it by making different styles for each different colour, but that adds a huge amount of markup and it's a mess to manage. Because they're also the styles, I read that bindings won't work because styles are sealed once they're initialized.
Has anyone figured out a way to just change colours of a style without having to make multiple separate styles?
WPF has some nice markup for this very problem. You can use DynamicResource to allow the style to refresh every time the resource gets changed. Here's an example:
<SolidColorBrush x:Key="ColourAccent">#448AFF</SolidColorBrush>
<Style TargetType="Button">
<Setter Property="Background" Value="{DynamicResource ColourAccent}"/>
</Style>
This of course is a very simple implementation of this method, but essentially the DynamicResource is a reference to ColourAccent that, if the resource was to change, will automatically reflect the change in the style.
Now, changing the resource is a slightly different problem, for theming your styles, you need somewhere to put all of your colours, the solution here is to use multiple ResourceDictionaries and using MergedDictionaries. Let me show you what I mean:
Firstly, add a folder to your project called Themes, it'll just make things easier. Also, add that Style I mentioned earlier to either the Window.Resources or App.Resources, it's pretty important.
You need to add a ResourceDictionary file to the folder (Call it Amber.xaml), it'll look something like this:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<!-- Amber -->
<SolidColorBrush x:Key="ColourAccent">#FFC107</SolidColorBrush>
</ResourceDictionary>
Here is a simple resource dictionary, it contains one resource called ColourAccent, now we need to create another one (Call it Blue.xaml), but with a different colour:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<!-- Blue -->
<SolidColorBrush x:Key="ColourAccent">#448AFF</SolidColorBrush>
</ResourceDictionary>
The magic here will become clear soon enough. Having multiple resource dictionaries with resources under the same name will allow you to create themes. The method of which is to swap the current resource dictionary for a new one, and by doing so, the DynamicResource will notice there has been a change and it'll refresh the control styles.
Now you have two resource dictionaries, you need to work out which dictionary to use. Firstly, we need to define the default resource dictionary that your application is going to use, you need to declare this in App.xaml.
<Application ...>
<Application.Resources>
<ResourceDictionary>
...
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="pack://application:,,,/YourNamespace;component/Themes/Amber.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
So here you'll see the MergedDictionaries element, this is where the magic happens. If you run the app now, you should see that any buttons will have a background colour of Amber. Cool, huh?
Now it gets a little bit trickier, we will be removing the resource dictionary that is currently in the dictionary and replacing it with a different theme (a different resource dictionary).
Here is some C# to do that:
Disclaimer: I just threw this code together, there is almost certainly a better way, but you get the idea. Put the following code in a mouse click event, or somewhere where you can step it through to see what's happening.
Firstly, remove the current theme from the merged dictionaries.
//Find the current dictionary
ResourceDictionary oldDictionary = App.Current.Resources.MergedDictionaries.FirstOrDefault();
//If we found one, remove it.
if (dictionary != null)
App.Current.Resources.MergedDictionaries.Remove(oldDictionary);
Now we just need to add a different resource dictionary. I'm just going to add the Blue theme for the sake of an example:
//Declare some variables.
string folderPath = "/YourNamespace;component/Themes/";
string desiredTheme = "Blue";
//Create the new resource dictionary
ResourceDictionary newDictionary = new ResourceDictionary();
newDictionary.Source = new Uri(string.Format("{0}{1}.xaml", folderPath, desiredTheme), UriKind.RelativeOrAbsolute);
//Add the resource dictionary to the merged dictionaries.
App.Current.Resources.MergedDictionaries.Add(newDictionary);
Now if all goes well, the background for any buttons in your app should now be Blue. Hooray!
Using this method, which in essence is creating multiple resource dictionaries each with resources under the same name, you can create multiple themes for your application. This isn't restricted to colours, you can have entire styles which are theme specific, where one theme might display a button in a completely different way as another style. Experiment and see what you can come up with. Good luck!

Why does overriding ApplicationPageBackgroundThemeBrush not work?

I am trying to define a default background colour for my Windows 8 Store application, but although it shows correctly in the XAML editor and in Blend, it comes up with the default black background when run on Windows 8 and in the Windows RT emulator.
I created a brand new Windows 8 app based on the "Split App" VS 2012 template and modified App.xaml to specify a new value for ApplicationPageBackgroundThemeBrush.
This is what my App.xaml looks like:
<Application
x:Class="App3.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App3"
xmlns:localData="using:App3.Data">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<!--
Styles that define common aspects of the platform look and feel
Required by Visual Studio project and item templates
-->
<ResourceDictionary Source="Common/StandardStyles.xaml"/>
</ResourceDictionary.MergedDictionaries>
<!-- Application-specific resources -->
<x:String x:Key="AppName">App3</x:String>
<!-- Basic foreground and background colours -->
<SolidColorBrush x:Key="ApplicationPageBackgroundThemeBrush" Color="#FF3CA5DC"/>
<SolidColorBrush x:Key="ApplicationPageForegroundThemeBrush" Color="White"/>
</ResourceDictionary>
</Application.Resources>
It seems that those 2 brushes are only used by a few styles in StandardStyles.xaml, one of them is
<Style x:Key="LayoutRootStyle" TargetType="Panel">
which you can apply to your root panel. But your changes in the App.xaml doesn't affect this style. It affects only further use of this brush, so if you want to use those particular brushes I see the following variants:
1) Declare them in your App.xml and use it further like:
<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
2) Declare them in StadardStyles.xaml under
<ResourceDictionary.ThemeDictionaries>
<ResourceDictionary x:Key="Default">
<!-- Style Goes Here -->
</ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>
In this case all StandardStyles will be affected, but you should use LayoutRootStyle in your Grid also.
But really, using those brushes show so litle profit that I think it is better just set your panel background to what you need.

Silverlight ResourceDictionary not available

I've put a few good hours into this.. I'm unable to see the various styles I have defined in a global Resource dictionary. The external file is called Styles.xaml. What am I missing?
There are a few things to consider using MergedDictionaries.
First you should set the BuildAction of the ResourceDictionary (Styles.xaml) to Resource or Content (I tried it with Resource).
Second in your App.xaml do not define a Key for the ResourceDictionary (remove x:Key="ButtonStyles")
Then put all other resources in your Application.Resources in the ResourceDictionary.
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/Assets/Styles.xaml"/>
</ResourceDictionary.MergedDictionaries>
<CCE_2009_Client_ViewModels:ViewModelLocator x:Key=ViewModelLocatorDataSource/>
<!-- Any additional resources -->
</ResourceDictionary>
</Application.Resources>
After all this is done then you should select the Style in the Properties Window.
Do you have referenced CCE_2009.Client assembly (project) in the project you want to use this style?
If not this can be a fix for your problem.