How to set DataContext of a single control to code the behind

Question

How to set DataContext of a single control to code the behind?
Cannot use DataContext of the Windows as it points to something else.
For a single control I would like to set the DataContext to codebehind but cannot figure it out.
Not using MVVM.

This is not working as the RelativeSource appears to the ComboBox.

<ComboBox DataContext="{Binding RelativeSource={RelativeSource Self}}" ItemsSource="{Binding Path=Chars}" SelectedItem="{Binding Path=Comma}" Width="40" PresentationTraceSources.TraceLevel="High" />

It is a Page - not a Window

This works:

<ComboBox DataContext="{Binding RelativeSource={RelativeSource AncestorType=Page}}" ItemsSource="{Binding Path=Chars}" SelectedItem="{Binding Path=Comma, Mode=TwoWay}" Width="40" PresentationTraceSources.TraceLevel="High" />

Is there a better solution?

Answer 1

Converting my comment to an answer :

since you aren't following MVVM, you could get away with giving your ComboBox a Name and assigning DataContext to it directly from your code-behind.

<ComboBox x:Name="cmBox" ... />

and in the code-behind class's ctor:

Loaded += (sender, args) => cmBox.DataContext = this;

saying ^^, there is nothing wrong with using a RelativeSource Binding to assign DataContext directly from xaml, It's what I'd prefer to do myself(but I do "try to" comply with MVVM in my apps).