late 14c., "one who handles" anything, agent noun from handle (v.). Specific sense of "one engaged in trade" is from 1690s; that of "prizefighter's assistant" (1916) was earlier used in reference to dogfights and cockfights (1825).
权威例句
1. A good handler can lessen faults.
一个好的Handler能减少失误.
2. The sword - handler took the cape, looking up at Brett.
随从接过斗篷, 一面抬头看看勃莱特.
3. The exception handler chosen is said to catch the exception.
异常处理程序的选择要处理的异常对象被称为异常捕获.
4. Designer verbs associate a menu item with an event handler.
设计器谓词使菜单项与事件处理程序关联.
5. In some cases you can dissociate a handler from an event.