多项选择题

A. Add the OnClick event handler for the Login button to the code used in the custom user control.
B. Add the OnClick event handler for the Login button to the code used in the Web Form where the control is added.
C. In the Page_Load method of the Web Form, add a code segment to set the visibility of the TextBox and Button controls where the control is added.
D. In the Page_Load method of the custom user control, add a code segment to set the visibility of the TextBox and Button controls.