Invalid conversion from 'DWORD' to 'const char *' - c++

Question

I'm trying to compile some code, but I'm getting an error:
Error invalid conversion from DWORD to const char *
Here's the code I'm trying to compile:
hWindow = FindWindow(NULL, "Window");
if (hWindow){
GetWindowThreadProcessId(hWindow, &pid);
}
hProcess = OpenProcess(PROCESS_ALL_ACCESS, 0, pid);
if(hProcess != NULL) {
SetWindowText(GetDlgItem(MyWindow, MyStatic), pid);
}
How do I convert a DWORD to a const char *?

Answer 1

SetWindowText expects a const char * (i.e. a C-string) and you are passing it a number (pid), it's obvious that you get an error.
The standard C++ way to perform the conversion is to use a string stream (from header <sstream>:
std::ostringstream os;
os<<pid;
SetDlgItemText(MyWindow, MyStatic, os.str().c_str());
(here I used SetDlgItemText instead of GetDlgItem+SetWindowText to save typing, but it's the same thing)
Alternatively, you can use snprintf.
char buffer[40];
snprintf(buffer, sizeof(buffer), "%u", pid);
SetDlgItemText(MyWindow, MyStatic, buffer);

Answer 2

In this line
SetWindowText(GetDlgItem(MyWindow, MyStatic), pid);
pid is a DWORD (as you used it in GetWindowThreadProcessId(hWindow, &pid) which takes a LPDWORD as the second argument). However, SetWindowText expects a C-string as it's second argument, so instead of pid, you must pass a value of type char * or char [].
To display the value of pid, you can make use of sprintf:
char * str = new char[10];
sprintf(str,"%d",pid);
You may have to modify the size of str a little (10 might be too small, or bigger than necessary - that's up to you and your situation).