CODEWITHSUNDEEP
xamarinxamarin.forms
Alan2
Alan2

Reputation: 24572

Is there a way I can access a static resource in my C# code?

In my App.XAML I have this:

<Application xmlns:converters="clr-namespace:Japanese" xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="Japanese.App">
<Application.Resources>
        <Color x:Key="TextColor1">#123456</Color>

I can access this value in XAML like this:

<Style TargetType="Label">
        <Setter Property="TextColor" Value="{StaticResource TextColor1}" />
</Style>

But is there also a way that I can access this in my back end C#

vm.C1BtnLabelTextColor = phrase.C1 == true ? Color.FromHex("#123456") : Color.FromHex("#0000FF");

For example here I would like to replace: 

Color.FromHex("#123456")

with the value of the StaticResource

Upvotes: 14

Views: 7646

Answers (4)

dmoney
dmoney

Reputation: 1

This definitely works better especially when you are using MergedDictionaries

Upvotes: -2

&#194;ngelo Polotto
&#194;ngelo Polotto

Reputation: 9531

The solution proposed here (Application.Current.Resources["TextColor1"];) works only if you don't have ResourceDictionary.MergedDictionaries, otherwise, you need the following approach:

// helper method
private object GetResourceValue(string keyName)
{
    // Search all dictionaries
    if (Xamarin.Forms.Application.Current.Resources.TryGetValue(keyName, out var retVal)) {}
    return retVal;
}

Exemple how to use:

ButtonColor = (Color) GetResourceValue("Primary");

This method will assure that all merged resources are iterated to find your current resource.

Reference: https://forums.xamarin.com/discussion/146001/how-to-get-a-rsource-from-an-mergeddictionary-in-c-code

Upvotes: 2

EvZ
EvZ

Reputation: 12179

ResourceDictionary is a repository for resources that are used by a Xamarin.Forms application. Typical resources that are stored in a ResourceDictionary include styles, control templates, data templates, colors, and converters.

In XAML, resources that are stored in a ResourceDictionary can then be retrieved and applied to elements by using the StaticResource markup extension. In C#, resources can also be defined in a ResourceDictionary and then retrieved and applied to elements by using a string-based indexer. However, there's little advantage to using a ResourceDictionary in C#, as shared objects can simply be stored as fields or properties, and accessed directly without having to first retrieve them from a dictionary.

In short: ResourceDictionary is a Dictionary.
To read a value from a Dictionary you have to provide a Key. In your case the Key is "TextColor1". So using C# here is how you could read the value from Application.Resources:

var txtColor1 = (Color) Application.Current.Resources["TextColor1"];

Please note that you have to cast the returned value to a desired type, thats because the Dictionary is "generic".

You could also create an Extension Method if you have to reuse it in your project.

Source: Official documentation

Upvotes: 19

Bruno Caceiro
Bruno Caceiro

Reputation: 7189

You can access like this: 

Application.Current.Resources["TextColor1"];

Upvotes: 6

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