按照MSDN的解释：
Overridden. Increases the number of references to a FormRun object. This increase prevents the release of the object memory during garbage collection when the FormRun object goes out of scope.
该方法可重载。用于增加一个FormRum对象的引用计数，防止被系统的垃圾回收机制回收了FormRun对象的内存。