B) Sina weibo
C) We chat
You work as software developer at XYZ inc. You need to develop a Windows form that provides online help for users. You want the help functionality to be available when users press the F1 key. Help text will be displayed in a pop-up window for the text box that has focus. To implement this functionality, you need to call a method of the HelpProvider control and pass the text box and the help text. What should you do?