RadWindow icon not shown in taskbar

Question

A similar question is wrongly marked as duplicate.

The given answer works, but it's not XAML-ish doing. My self-answer post below is recommended from Telerik.

Answer 1

In the Telerik example, there are three lines in MainWindow as below;

xmlns:navigation="clr-namespace:Telerik.Windows.Controls.Navigation;assembly=Telerik.Windows.Controls.Navigation"
navigation:RadWindowInteropHelper.ShowInTaskbar="True"
navigation:RadWindowInteropHelper.Icon="icon.ico"

Of course, you should prepare icon.ico file.

Full xaml code is attached as below.

<telerik:RadWindow x:Class="RadWindowAsMainWindow.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation"
        xmlns:navigation="clr-namespace:Telerik.Windows.Controls.Navigation;assembly=Telerik.Windows.Controls.Navigation"
        navigation:RadWindowInteropHelper.ShowInTaskbar="True"
        navigation:RadWindowInteropHelper.Icon="icon.ico"
        Header="MainWindow" Height="350" Width="525">
    <Grid>
        <TextBlock Text="The application is shown inside RadWindow." />
    </Grid>
</telerik:RadWindow>