Set static resource in code
Solution 1
A StaticResource
is static. You can't change them once the application has compiled.
For this purpose, there is DynamicResource
:
A DynamicResource will create a temporary expression during the initial compilation and thus defer lookup for resources until the requested resource value is actually required in order to construct an object.
Also note that you can find the reference to the other resource better using FindResource
. Try something like this (full working sample):
In MainPage.xaml
:
<Window.Resources>
<Color R="255" x:Key="styleRed" />
<Style x:Key="abc" TargetType="StackPanel">
<Setter Property="Background" Value="Blue" />
</Style>
</Window.Resources>
In MainPage.xaml.cs
:
Style style = this.FindResource("abc") as Style;
var r = this.FindResource("styleRed");
foreach (Setter s in style.Setters)
{
if (s.Property == StackPanel.BackgroundProperty)
{
s.Value = r;
}
}
Solution 2
Why are you modifying the Style instead of setting the Background
-Property of your targeted StackPanel
directly? Since a 'Local value' has a higher precedence than 'Style setters' the value that you write into Background
from code behind would be used
Means:
(1) Give a name to your stackpanel x:Name="spBla"
(2) Assign the Brush to the Background
of spBla
( something like spBla.Background=Application.Current.Resources["styleRed"] as SolidColorBrush;
)
You can learn more about value precedence here:
http://msdn.microsoft.com/en-us/library/ms743230(v=vs.110).aspx
Solution 3
xaml resource
<Window.Resources>
<LinearGradientBrush x:Key="GrayBlueGardientBrush"
StartPoint="0,0" EndPoint="1,1">
<GradientStop Color="DarkCyan" Offset="0"/>
<GradientStop Color="#CCCCFF" Offset="0.5"/>
<GradientStop Color="DarkCyan" Offset="1"/>
</LinearGradientBrush>
</Window.Resources>
CS
private void Button_Click(object sender, RoutedEventArgs e)
{
var r = this.FindResource("GrayBlueGardientBrush");
(sender as Button).Background = r as LinearGradientBrush;
}
Arn Vanhoutte
Updated on July 16, 2022Comments
-
Arn Vanhoutte almost 2 years
I have a few styles in my
App.xaml
file:<SolidColorBrush x:Key="styleBlue" Color="#FF4B77BE"/> <SolidColorBrush x:Key="styleRed" Color="#FFF64747"/> <SolidColorBrush x:Key="styleOrange" Color="#FFF89406"/> <SolidColorBrush x:Key="styleGreen" Color="#FF1BBC9B"/> <SolidColorBrush x:Key="styleYellow" Color="#FFF9BF3B"/> <Style x:Key="stackpanelBackground" TargetType="StackPanel"> <Setter Property="Background" Value="{StaticResource styleBlue}"/> </Style>
I want to change the
BackgroundProperty
in the code of mymainpage.xaml.cs
.I tried using this:
Style style = Application.Current.Resources["stackpanelBackground"] as Style; style.Setters.SetValue(StackPanel.BackgroundProperty, "{StaticResource styleRed}");
But I get a catastrophic failure exception. I think it has to do with
{StaticResource styleRed}
. Is there a better way to do this?