<Window x:Class="WindowsApplication1.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Proszę czekać" Height="200" Width="300" ResizeMode="NoResize">
  <Grid>
    <StackPanel Style="{DynamicResource DialogStyle}">
      <Label Style="{DynamicResource HeadingStyle}">Ładowanie...</Label>
      <ProgressBar Value="35" MinHeight="20" Margin="20"/>
      <Button Style="{DynamicResource CancelButtonStyle}" Width="70"
        Click="Cancel_Click">Anuluj</Button>
    </StackPanel>
  </Grid>
</Window>