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

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).