Add Button and TextBox to StackPanel
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="" Height="300" Width="300"> <StackPanel> <TextBlock>Hello World</TextBlock> <Button Width="100">Click Me</Button> </StackPanel> </Window>