Marshal.ReleaseComObject

 释放COM对象相关文档：

http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.marshal.releasecomobject.aspx

Marshal.FinalReleaseComObject 方法

http://msdn.microsoft.com/zh-cn/library/system.runtime.interopservices.marshal.finalreleasecomobject.aspx

Marshal.ReleaseComObject存安全隐患