Thread: EnumPropsEx Error

Hello,

I am trying to get the properties of a Microsoft's Notepad.exe window. I have an instance of this application running when I execute the code below.

Code:

#include <iostream>
#include <windows.h>

using namespace std;

BOOL CALLBACK PropEnumProcEx(HWND hwnd, LPTSTR lpszString, HANDLE hData, ULONG_PTR dwData) {
  cout << "Property Label: " << lpszString << "." << endl;
  return true;
}

int main()
{
    HWND hNote = FindWindow("Notepad", NULL);
    cout << "Notepad's handle: " << hNote << endl;
    EnumPropsEx(hNote, PropEnumProcEx, 0);
    cout << "Done" << endl;
    return 0;
}

The output is:

Notepad's handle: 0x7e0b7e
Property Label:

Then i receive a "properties.exe has encountered a problem and needs to close. We are sorry for the inconvenience." Windows error message.

{P.S. my program is called properties.exe}

If I don't have a reference to lpszString in the callback function then the code executes as expected through to the end. I suspect I am not using the pointer of the string correctly...?

If someone could shed some light that would be appreciated.

Thanks,

Yes, indeed it is an atom; namely, an integer atom.

I changed the callback procedure to the following:

Code:

BOOL CALLBACK PropEnumProcEx(HWND hwnd, LPTSTR lpszString, HANDLE hData, ULONG_PTR dwData) {
  if (HIWORD(lpszString) == 0) {
    WORD the_atom = LOWORD(lpszString);
    char buffy[100] = {0};
    GetAtomName(the_atom, buffy, 100);
    cout << "It is an atom: " << buffy << endl;
    cout << "Data: " << hData << endl;
  }else {
    cout << "Property Label: " << lpszString << "." << endl;
  }
  return true;
}

I have two follow-ups.

1. Winspector Spy shows there are two integer atoms, but I only get 1. What is going on here?
2. What can I do with the hData handle?

Thanks for your assistance,

1. A global atom not used in SetProp(), or in another window...?
2. It's whatever was passed to SetProp(), so you can't do much unless you know what it is.

gg