一个臭虫???在C ++中实现IUnknown

本文介绍了一个臭虫???在C ++中实现IUnknown的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 您好，全部： 请参阅：  http://msdn.microsoft .com / zh-CN / library / office / cc839627.aspx 我想有一个错误： InterlockedIncrement（m_cRef）; 应该是 InterlockedIncrement（& m_cRef）; 和 ULONG ulRefCount = InterlockedDecrement（m_cRef）; 应该是 ULONG ulRefCount = InterlockedDecrement（& m_cRef）; 请确认...... 干杯 Pei 解决方案 Ye s，这是一个错字。 虽然技术上很有趣，因为没有显示m_cRef的声明，这个特殊的例子仍然可能是通过假设m_cRef是使用支持隐式的运算符来实现运行符号 volatile unsigned long * 和 ULONG 之类的这个： #include< windows.h> class MyRefCount { public： MyRefCount（）：n（1）{} operator volatile unsigned long *（） { return& n; } 运营商ULONG（） { return n; } 私人： volatile ULONG n; }; class CMyMAPIObject { public： ULONG Release（）; private： MyRefCount m_cRef; }; ULONG CMyMAPIObject :: Release（） { //减少对象的内部计数器。 ULONG ulRefCount = InterlockedDecrement（m_cRef）; if（0 == m_cRef） {删除此; } 返回ulRefCount; } int WINAPI WinMain（HINSTANCE hInstance，HINSTANCE hPrevInstance，LPSTR sCmdLine，int nCmdShow） { CMyMAPIObject * m = new CMyMAPIObject; m-> Release（）; 返回0; } 但这只是一个C ++特技。   ;; - ） 我认为你最有意义的是它是一个错字。 Hi, all:Please refer to :  http://msdn.microsoft.com/en-us/library/office/cc839627.aspxI guess there is a bug:InterlockedIncrement(m_cRef);should beInterlockedIncrement(&m_cRef);andULONG ulRefCount = InterlockedDecrement(m_cRef);should beULONG ulRefCount = InterlockedDecrement(&m_cRef);Please confirm...CheersPei 解决方案 Yes, it is a typo.Although it's amusing that technically, because the declaration of m_cRef is not shown, this particular example could still be correct (with a little tricky thinking alone) by assuming that m_cRef is implemented with a class that supports implicit cast operators to both volatile unsigned long* and ULONG like this:#include <windows.h>class MyRefCount{public:MyRefCount() : n(1) {}operator volatile unsigned long*(){return &n;}operator ULONG(){return n;}private:volatile ULONG n;};class CMyMAPIObject{public:ULONG Release();private:MyRefCount m_cRef;};ULONG CMyMAPIObject::Release(){ // Decrement the object's internal counter. ULONG ulRefCount = InterlockedDecrement(m_cRef); if (0 == m_cRef) { delete this; } return ulRefCount;}int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR sCmdLine, int nCmdShow ){CMyMAPIObject* m = new CMyMAPIObject;m->Release();return 0;}But that's just a C++ stunt.  ;-)I think that it makes the most sense that you're right about it being a typo. 这篇关于一个臭虫???在C ++中实现IUnknown的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！