This control is deprecated in favor of using the PlaceholderText property on the TextBox controls built in to Windows 8.1. Visit Callisto Migration Tips for specific information.

WaterMarkTextBox is a derivitave of TextBox that adds only the functionality of providing a default text 'hint' in the text input area if no text exists. This is helpful in providing some tip to your users e.g., "Enter your name here..." which will automatically go away when the user starts typing. The Watermark has no affect on the Text property or other aspects of the TextBox control.

Declarative:

<callisto:WatermarkTextBox Watermark="Enter your name..." />

Code:

WatermarkTextBox wmt = new WaterMarkTextBox();
wmt.Watermark = "Enter your name...";

None currently

This is based on the Silverlight implementation of watermark text box controls.