Hello Joe,
Well, the Multiple choice control is defined in the source code and therefore it is not listed in Site Manager.
Anyway, the field of type Multiple choice saves selected values in the same format you want. It means that this control separates selected values with a pipe (
ItemA|ItemB|ItemC).
If you want to implement this functionality in your custom form control, you will need to create a string which will contain selected values separated by the pipe in the
Get method of
Value property and parse it in the
Set method.
If you need more information about developing form controls, I would like to point you to the following article:
Developing form controlsBest regards,
Michal Legen