import clr

from System.Windows import Application, Thickness
from System.Windows.Controls import (
 Button, Canvas, Orientation,
 StackPanel, TextBox #WatermarkedTextBox
)

xaml = Application.Current.LoadRootVisual(Canvas(), "app.xaml")
textblock = xaml.FindName('textblock')

panel = StackPanel()
panel.Margin = Thickness(50)
panel.Orientation = Orientation.Horizontal


button = Button()
button.Content = 'Push Me'
button.FontSize = 18
button.Margin = Thickness(10)

waterbox = TextBox() #WatermarkedTextBox()
waterbox.FontSize = 18
waterbox.Margin = Thickness(10)
waterbox.Width = 200
#waterbox.Watermark = 'Type Something Here'

def onClick(s, e):
 textblock.Text = waterbox.Text

button.Click += onClick

panel.Children.Add(button)
panel.Children.Add(waterbox)

xaml.Children.Add(panel)