BasedOn="{StaticResource {x:Type TextBox}}" in Code Behind for Style

Question

How can you set the following in code behind?

<Style TargetType="{x:Type TextBox}" BasedOn="{StaticResource {x:Type TextBox}}">

I'm using a Theme merged in App.xaml. It works great for all Controls but when I define a Style for something, e.g. TextBox, the Theme Style doesn't get picked up unless I use BasedOn like above, instead it gets the default TextBox Style.

Now I'm creating a DataGridTextColumn in code behind and I can't get the BasedOn part to work for the EditingElementStyle

Style editingStyle = new Style(typeof(TextBox));
editingStyle.BasedOn = ...?;

Any suggestions? Also, is there any way to get the Theme Style instead of the default Style applied without using BasedOn?

Thanks

Hypothetical

You are trying to get the Theme applied to a given control and have the local style override the Theme components which it affects? – Gleeman

@Aaron: I'm using a Theme which affects all controls. But in many places I need to add specific setters, triggers etc. Binding ListBoxItem.IsSelected in the ListBox ItemContainerStyle for example. I want the Theme Style applied with an additional setter – Hypothetical

Answer 1

Try this:

editingStyle.BasedOn = (Style) FindResource(typeof (TextBox))

And I don't know any way how you can make it apply the Theme style without specifying BasedOn. If there is such a way, I would like to know it too...

Unsteel

Answer 2

This should work:

Style baseStyle = new Style(typeof(TextBox));
Style editingStyle = new Style(typeof(TextBox));
editingStyle.BasedOn = baseStyle;

You can also do it in the constructor:

Style editingStyle = new Style(typeof(TextBox), baseStyle);

Auria

Thanks for your answer! Yes, I hoped that would work to but the Theme Style isn't picked up for some reason. If I do it in Xaml it works.. – Hypothetical

Answer 3

I like the answer of Pavlo Glazkov, but it does not compile.

FindResource is (non-static) member of FrameworkElement. It is required to identify the context of the search request.

So I recommend this:

style.BasedOn = (Style)frameworkElement.FindResource(typeof(TextBox));

Goar

Answer 4

Here's a post that occurred a few years after this question and provides a functional way to reference theme from XAML. Per https://mcmap.net/q/233897/-accessing-a-resource-via-codebehind-in-wpf

First - Define the XAML resource dictionary with an x:class identifier along with an x:Key of your resource

ResourceDictionary x:Class="YourNameSpaceHere.DataGridCellTemplates"

<Style x:Key="ValidationError_TextBox" TargetType="{x:Type TextBox}">
    <Setter Property="Validation.ErrorTemplate" Value="{StaticResource ValidationErrorTempate}" />
</Style>

Second - Create a .cs file that will initialize the resource class.

using System.Windows;

namespace YourNameSpaceHere
{
    public partial class DataGridCellTemplates : ResourceDictionary
    {
        public DataGridCellTemplates()
        {
            InitializeComponent();
        }
    }
}

Lastly - Reference from you code

using YourNameSpaceHere;
....
var res = new DataGridCellTemplates();
Style test = res["ValidationError_TextBox"] as Style;

Solfatara