Accessing a resource via codebehind in WPF
I have a custom collection defined in my window resources as follows (in a Sketchflow app so the window is actually a UserControl):
<UserControl.Resources>
<ds:MyCollection x:Key="myKey" x:Name="myName" />
</UserControl.Resources>
I want to be able to refer to this collection in the codebehind, which I expected would be by the x:Name, but I can't seem to access it.
I can get a re开发者_开发问答ference to it using
myRef = (MyCollection) this.FindName("myKey");
but this seems hackish. Is this bad practice, and what would be better? Thanks :)
You should use System.Windows.Controls.UserControl
's FindResource()
or TryFindResource()
methods.
Also, a good practice is to create a string constant which maps the name of your key in the resource dictionary (so that you can change it at only one place).
You may also use this.Resources["mykey"]
. I guess that is not much better than your own suggestion.
Not exactly direct answer, but strongly related:
In case the resources are in a different file - for example ResourceDictionary.xaml
You can simply add x:Class
to it:
<ResourceDictionary x:Class="Namespace.NewClassName"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
<ds:MyCollection x:Key="myKey" x:Name="myName" />
</ResourceDictionary>
And then use it in code behind:
var res = new Namespace.NewClassName();
var col = res["myKey"];
If you want to access a resource from some other class (i.g. not a xaml codebehind), you can use
Application.Current.Resources["resourceName"];
from System.Windows
namespace.
You can use a resource key like this:
<UserControl.Resources>
<SolidColorBrush x:Key="{x:Static local:Foo.MyKey}">Blue</SolidColorBrush>
</UserControl.Resources>
<Grid Background="{StaticResource {x:Static local:Foo.MyKey}}" />
public partial class Foo : UserControl
{
public Foo()
{
InitializeComponent();
var brush = (SolidColorBrush)FindResource(MyKey);
}
public static ResourceKey MyKey { get; } = CreateResourceKey();
private static ComponentResourceKey CreateResourceKey([CallerMemberName] string caller = null)
{
return new ComponentResourceKey(typeof(Foo), caller); ;
}
}
I got the resources on C# (Desktop WPF W/ .NET Framework 4.8) using the code below
{DefaultNamespace}.Properties.Resources.{ResourceName}
A nice clean example from Microsoft documents makes it simple:
private void myButton_Click(object sender, RoutedEventArgs e)
{
Button button = (Button)sender;
button.Background = (Brush)this.FindResource("RainbowBrush");
}
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