I have an issue, I can"t figure out how to get the char type array( and convert it to wchar_t )or wide char array itself in a created window which would be a reference to LPWSTR( wide-character pointer) for a WinAPI app. I have tried many conversion approaches but it didn't work out, because all the time's characters were not quite the ones to had to be. In the first place, I need the char because I want to display randomly generated ASCII based characters. Code sample:
char * gen() {
static char ha[10];
for (int i = 0;i < 10;i++)
{
char p = (rand() % 65 + 90);
while (p == ' ')
{
p = (rand() % 65 + 90);
}
ha[i] = p;
}
return ha;
}
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1:
char* m;
m = gen();
//conversion which I couldn't figure out goes somewhere here
wchar_t* xa;
xa = m;
CreateWindow(L"STATIC",xa, WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
X += 30;
break;
}
break;
...
}
As you can see, the generated strings should be 65-90 (Latin capital letters) although I'm getting everything what's in Unicode (probably because converted incorrectly).
Your gen()
function is not returning a null-terminated string, but CreateWindow()
expects one.
You can't assign a char*
pointer to a wchar_t*
pointer. You have to actually convert the char
data to wchar_t
data, such as with MultiByteToWideChar()
or equivalent. You can append a null-terminator to the end of that converted wchar_t
string, eg:
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1: {
char* m = gen();
int wlen = MultiByteToWideChar(CP_ACP, 0, m, 10, NULL, 0);
wchar_t* xa = new wchar_t[wlen+1];
MultiByteToWideChar(CP_ACP, 0, m, 10, xa, wlen);
xa[wlen] = L'\0';
CreateWindow(L"STATIC", xa, WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
delete[] xa;
X += 30;
break;
}
...
}
break;
...
}
You can instead use CreateWindowA()
, then you won't need MultiByteToWideChar()
, but you will still need to add a null terminator, eg:
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1: {
char* m = gen();
char* xa = new char[11];
memcpy(xa, m, 10);
xa[10] = '\0';
CreateWindowA("STATIC", xa, WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
delete[] xa;
X += 30;
break;
}
...
}
break;
...
}
Alternatively:
#include <string>
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1: {
char* m = gen();
std::string xa(m, 10);
CreateWindowA("STATIC", xa.c_str(), WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
X += 30;
break;
}
...
}
break;
...
}
However, I would suggest changing your gen()
function instead to output a null-terminated string to begin with, eg:
char* gen()
{
static char ha[11]; // <-- add +1 here
for (int i = 0; i < 10; i++)
{
wchar_t p = (rand() % 65 + 90);
while (p == ' ')
{
p = (rand() % 65 + 90);
}
ha[i] = p;
}
ha[10] = '\0'; // <-- add this
return ha;
}
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1: {
char* m = gen();
CreateWindowA("STATIC", m, WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
X += 30;
break;
}
...
}
break;
...
}
Or:
wchar_t* gen()
{
static wchar_t ha[11];
for (int i = 0; i < 10; i++)
{
wchar_t p = (rand() % 65 + 90);
while (p == L' ')
{
p = (rand() % 65 + 90);
}
ha[i] = p;
}
ha[10] = L'\0';
return ha;
}
WndProc(...)
{
...
case WM_COMMAND:
switch (LOWORD(wparam)) {
case 1: {
wchar_t* m = gen();
CreateWindow(L"STATIC", m, WS_VISIBLE | WS_CHILD | WS_EX_WINDOWEDGE | WS_BORDER, 10, X, 100, 20, hWnd, NULL, NULL, NULL);
X += 30;
break;
}
...
}
break;
...
}
Now, that being said, your gen()
function is calculating its random letters incorrectly. To produce a string that contains only ASCII capital letters, your function should look like this instead:
char* gen()
{
static char ha[11];
for (int i = 0; i < 10; i++)
{
ha[i] = (rand() % 26) + 'A'; // <-- produces letters in the range A..Z only ...
}
ha[10] = '\0';
return ha;
}
Or:
wchar_t* gen()
{
static wchar_t ha[11];
for (int i = 0; i < 10; i++)
{
ha[i] = (rand() % 26) + L'A';
}
ha[10] = L'\0';
return ha;
}
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