Event mouse not trigger as expected in usercontrol

Question

I implement own Topbar control. the problem window only can move when i click into textblock. first i suggest cause height control is 0. after i set, still only textblock part can trigger left click event.

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="Inventory.Views.Controls.Topbar"
    Height="50"
    MouseDown="MoveWindow_MouseDown">
    <StackPanel>
        <Grid>
            <Image Source="Resources/icon.png" />
            <TextBlock HorizontalAlignment="Center">Title</TextBlock>
            <WrapPanel HorizontalAlignment="Right">
                <Button Click="Minimize_Click">Minimize</Button>
                <Button Click="ToggleMaximize_Click">Maximize</Button>
                <Button Click="Close_Click">Close</Button>
            </WrapPanel>
        </Grid>
    </StackPanel>
</UserControl>

Behind MoveWindow_MouseDown implementation

private void MoveWindow_MouseDown(object sender, MouseButtonEventArgs e)
{
    if (e.ChangedButton == MouseButton.Left) 
        this.window.DragMove();
}