Question

该代码以印章显示。

char buffer[10]="hello";
AfxMessageBox((LPCTSTR)buffer);

而《刑法》则在国务厅展示。

AfxMessageBox(L"hello");

如果在我的法典中存在问题,有人可以告诉我,如果是这样的话,那是怎样把缓冲变量恰当地推给我。

Answer 1

The LPCTSTR type is a Long Pointer to a Transparent STRing. What s important here is the T, Transparent (at least I think the T stands for Transparent).

If your application is compiled as an ASCII application, all T types (like TCHAR) are redefined as their ASCII-counterpart. So TCHAR will become simply char.

If your application is compiled as Unicode, all T types are redefined as Unicode types. TCHAR becomes wchar_t.

所有Windows(和MFC)功能也是如此。所有Windows功能均以2种变量、ASCII版本(如电文BoxA)和Unicode版本(例如电文BoxW)组成。宣传方框本身只不过是对电文BoxA或电文BoxW(取决于你如何汇编)的定义。

In your example, buffer is defined as a char-vector type, but you convert it to a pointer to a transparent type. I assume that your application is compiled in Unicode, so LPCTSTR is actually a "wchar_t *". So this cast is incorrect.

Prepending the "hello" string with L, tells the compiler to theat the constant "hello" as a Unicode string, which makes it the correct type to be passed to the Unicode version of AfxMessageBox.

Answer 2

If you have _UNICODE and UNICODE flag defined in your compiler options then casting the string LPCTSTR will treat the string as an unicode string. In case windows, it will treat every 16 bytes as a single character and tries to find the corresponding unicode character. To make it display english character, use TCHAR while defining the array.

友情链接