Introduction - If you have any usage issues, please Google them yourself
Source text box input prompt WinForms function realization: derived from the TextBox control. Provides a private ListBox control treatment prompts. Handling KeyUp event to update the display matches the contents of the ListBox, KeyDown event handling special keys. Special key is up and down keys, select the prompt content, and the Tab key to accept the contents of selected prompt. Default Tab key is to change the focus and allows the user to input controls, rewritten IsInputKey method.