Binding property of static member of Application class - wpf

Question

I have a class "Application" which has a static member(MainWindow, inherits from DXWindow) like the following:
public static MainWindow MainWindowInstance
I instantiate and display it:
MainWindowInstance = new MainWindow();
MainWindowInstance.ShowDialog();
MainWindow has a property:
private Thickness _localAttachmentsButtonsMargin = new Thickness(0, 0, 5, 0);
public Thickness LocalAttachmentsButtonsMargin {
get {
return _localAttachmentsButtonsMargin;
}
set {
_localAttachmentsButtonsMargin = value;
NotifyPropertyChanged("LocalAttachmentsButtonsMargin");
}
}
I need to access the LocalAttachmentsButtonsMargin property from many other controls (like UserControls) in xaml.
What I tried so far is:
--> Access it with x:Static:
Margin="{Binding Path=MainWindowInstance.LocalAttachmentsButtonsMargin, Source={x:Static Application.Current}}"
--> Giving the UserControl a x:Name ("UcTmp"), provide a getter in the UserControl and access the property from code behind
Margin="{Binding ElementName=UcTmp, Path=LocalAttachmentsButtonsMargin}}"
public Thickness LocalAttachmentsButtonsMargin {
get {
Application.MainWindowInstance.LocalAttachmentsButtonsMargin;
}
}
But none of them both seems to work. I think I need the xaml equivalent to the one line of code in the getter given above.
An additional requirement is that the property in MainWindow needs to be updatable. Ideally the solution is able to update the view which is represented throught the UserControl if the property will be updated though some code.

Answer 1

Since you can only bind to properties, you should define MainWindowInstance as such:
public static MainWindow MainWindowInstance { get; set; }
It cannot be a field:
public static MainWindow MainWindowInstance;