Cast (const) char * to LPCWSTR

Question

I'm trying to use FindWindow() from WinAPI, and I want to ask an input for window's title from the user:

char *input;
cout << "Window title: ";
cin >> input;

Pretty standard. Now then, how do I convert this to LPCWSTR for FindWindow()?

I've already tried the following: _T(input), TEXT(input), (LPCWSTR)input but none of them worked. I also tried using wchar_t instead of char, but I need char everywhere else so then I get dozens of errors for using wchar_t instead of char...

Solution 1

You can use the wide variants of cin and cout:

wchar_t input[256];    // don't really use a fixed size buffer!
wcout << L"Window title: ";
wcin >> input;

Solution 2

I would use:

#ifdef UNICODE
typedef std::wstring String;
#define Char         wchar_t
#define out          wcout
#define in           wcin
#else
typedef std::string String;
#define Char        char
#define out         cout
#define in          cin
#endif

String input;
out << _T("Window title: ");
in >> input;
FindWindow(input.c_str(), ...);

If you are sure if UNICODE is defined you can do not make definition, but I recomend to use typedef for string type and use strings instead of api pointer types because it is type safer and it is easier to read code. In that case you need to call c_str() method which returns pointer to the first element. Also you can use &string[0].

Solution 3

Why do you think you want LPCWSTR? LPCWSTR is used in programs compiled for UNICODE. If you are using the char type everywhere then you should change the project property Character Set from 'Use UNICODE character set' to 'Use Multibyte Character Set." If you do that then FindWindow will accept a char array, like

char input[256];

Solution 4

First you could get users input as wchar_t* instead of char*. I think it would be the best option.

---

LPCWSTR is a pointer to wide char array, so you need to convert every char to wchar_t.

So lets say you have:

char arr[] = "Some string";

So your actions:

size_t size = strlen(arr);
wchar_t* wArr = new wchar_t[size];
for (size_t i = 0; i < size; ++i)
    wArr[i] = arr[i];

And if you need LPCWSTR you just use &wArr[0] (or some other index).

Important: don't forget to deallocate memory.

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Comments

[David Heffernan]

If you are going to read in an ANSI string then you may as well call FindWindowA. If you want to support UTF-16, then you'd better stop storing strings in ANSI char arrays.

[David Heffernan]

Why do you think you want LPCWSTR? Clearly because the compiler said so.