custom control的用法和樣例：
例句
- Designers must specify such mechanisms in detail, and programmers will likely need to implement them as custom controls.
設計者必須詳細地指定這種反饋機制，程序員也可能需要用定制控件來(lái)實(shí)現。 - A handy little custom control that removes all the grunt work of allowing the user to move items between two listboxes.
這個(gè)小定制控件去掉了讓用戶(hù)在兩個(gè)列表框之間進(jìn)行選擇的大量工作。
