BSTR、LPCOLESTR 等是什么意思? [英] What's the meaning of BSTR, LPCOLESTR, and others?

问题描述

如果 BSTR、LPCOLESTR、LPCWSTR、LPTSTR、LPCWCHAR 和许多其他的只是一堆解析为 wchar_t 的定义，它们的含义是什么?

What's the meaning of BSTR, LPCOLESTR, LPCWSTR, LPTSTR, LPCWCHAR, and many others if they're all just a bunch of defines that resolve to wchar_t anyway?

推荐答案

LPTSTR 和 LPWSTR 以及类似的定义实际上只是定义.BSTR 和 LPOLESTR 有特殊含义——它们表示指向的字符串是以特殊方式分配的.

LPTSTR and LPWSTR and similar defines are really just defines. BSTR and LPOLESTR have special meanings - they indicate the the string pointed to is allocated in a special way.

BSTR 指向的字符串必须用 SysAllocString() 系列函数分配.LPOLESTR 指向的字符串通常使用 CoTaskMemAlloc() 分配(这应该在文档中查找到接受/返回它的 COM 调用).

String pointed to by BSTR must be allocated with SysAllocString() family functions. String pointed to by LPOLESTR is usually to be allocated with CoTaskMemAlloc() (this should be looked up in the documentation to the COM call accepting/returning it).

如果违反 BSTR 和 LPOLESTR 指向的字符串的分配/解除分配要求，程序可能会遇到未定义的行为.

If allocation/deallocation requirements for strings pointed to by BSTR and LPOLESTR are violated the program can run into undefined behaviour.

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