Resharper offers to remove redundant inheritance from Window class in WPF

Question

In WPF projects Resharper offers to remove inheritance from Window class as redundant:

using System.Windows;

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }
}

It is become possible to remove even using System.Windows;.

public partial class MainWindow
{
    public MainWindow()
    {
        InitializeComponent();
    }
}

Why actually he offer this and why without that inheritance everything works fine? As I read in books of WPF any window anyway should be inherited...

Answer 1

XAML code-behind files are partial classes. The code generated by the compiler from the XAML file also includes the Window derivation so the one in the code-behind is redundant.

Answer 2

Your MainWindow class (like most designer-generated classes) is a partial class. This means that the implementation for your class can be broken up into multiple files, as long as they're all within the same assembly.

Because the designer-generated file for MainWindow also contains : Window, it's not necessary to include it in any other files.