ich habe einen Dialog erstellt und ein Listenfeld hinzugefügt, welches
Dateien akzeptiert.(Ich habe den Haken im Resourceneditor gesetzt)

Doch leider wird das Listenfeld nur grau dargestellet und aktzeptiert keine Dateien.

Hier der code:

#include "resource.h"
#include <windows.h>
#include <tchar.h>
#include "resource.h"

WNDPROC wndpList;

//Deklaration der WndProc Funktion und der Funktion fürs Fenster
LRESULT CALLBACK WndProc (HWND,UINT,WPARAM,LPARAM);
BOOL CALLBACK MainDlg (HWND,UINT,WPARAM,LPARAM);
//Fenster handles
HINSTANCE hInstMain;
HWND hwndMain;

int WINAPI WinMain (HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
{
	static TCHAR szAppName[]=TEXT("Dialog");
	HWND hwnd;
	MSG msg;
	RECT rect;
	WNDCLASS wndclass;

	hInstMain=hInstance;

	wndclass.style=0;
	wndclass.lpfnWndProc=WndProc;
	wndclass.cbClsExtra=0;
	wndclass.cbWndExtra=0;
	wndclass.hInstance=hInstance;
	wndclass.hIcon=LoadIcon(hInstance,"pIcon");
	wndclass.hCursor=NULL;
	wndclass.hbrBackground=NULL;
	wndclass.lpszMenuName=NULL;
	wndclass.lpszClassName=szAppName;

	if(!RegisterClass(&wndclass))
	{
		MessageBox(NULL,TEXT("Programm works with UNICODE!WinNT is required!"),szAppName,MB_ICONERROR);
		return 0;
	}

	hwnd=CreateWindowEx(NULL,szAppName,TEXT("Test"),
						WS_OVERLAPPED|WS_CAPTION|WS_SYSMENU|WS_BORDER ,
						320,250,
						CW_USEDEFAULT,CW_USEDEFAULT,
						NULL,NULL,hInstance,NULL);

	hwndMain=CreateDialog(hInstance,szAppName,hwnd,MainDlg);
	GetWindowRect(hwndMain,&rect);
	AdjustWindowRect(&rect,WS_EX_TOOLWINDOW|WS_BORDER,TRUE|WS_EX_ACCEPTFILES );
	SetWindowPos(hwnd,NULL,0,0,rect.right-rect.left,rect.bottom-rect.top,SWP_NOMOVE);
	ShowWindow(hwndMain,SW_SHOW);
	ShowWindow(hwnd,iCmdShow);
	UpdateWindow(hwnd);

	while(GetMessage(&msg,NULL,0,0))
	{
		if(hwndMain==0||!IsDialogMessage(hwndMain,&msg))
		{
			TranslateMessage(&msg);
			DispatchMessage(&msg);
		}
	}
	return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
	switch(message)
	{case WM_CREATE:
		return 0;
	case WM_SETFOCUS:
		SetFocus(hwndMain);
		return 0;
	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	case WM_DROPFILES:
	return(SendMessage(GetParent(hwnd), message, wParam, lParam));
        default:
            break;

	}
	return DefWindowProc(hwnd,message,wParam,lParam);
}
//Der Code fürs Hauptfenster
BOOL CALLBACK MainDlg (HWND hMain,UINT message,WPARAM wParam,LPARAM lParam)
{

	switch(message)
	{	

	case WM_INITDIALOG:
			wndpList = (WNDPROC)SetWindowLongPtr(GetDlgItem(hMain, IDC_LIST1), GWLP_WNDPROC, (LONG_PTR)WndProc);
     break;

	case WM_DROPFILES:
            {
              INT_PTR nCnt, nIndex, nSize;
              LPTSTR  pszFileName;
              HDROP   hDrop;

                hDrop = (HDROP)wParam;
                nCnt  = DragQueryFile(hDrop, (UINT)-1, NULL, 0); // Anzahl der Dateien ermitteln

                for(nIndex = 0; nIndex < nCnt; ++nIndex)
                {
                    // Länge des Dateinamens ermitteln
                    if(0 == (nSize = DragQueryFile(hDrop, nIndex, NULL, 0)))
                        continue;

                    pszFileName = new TCHAR[++nSize];

                    if(DragQueryFile(hDrop, nIndex, pszFileName, nSize))
                    {
                        // Den String nur dann hinzufügen, wenn er noch nicht vorhanden ist
                        if(0 > SendDlgItemMessage(hMain, IDC_LIST1, LB_FINDSTRINGEXACT, (WPARAM)-1, (LPARAM)pszFileName))
                            SendDlgItemMessage(hMain, IDC_LIST1, LB_ADDSTRING, 0, (LPARAM)pszFileName);
                    }

                    delete [] pszFileName;
                }
            }
           break;

		   //Sollte klar sein
	case WM_COMMAND:
		switch (LOWORD(wParam))
		{
		case IDC_CANCEL:
			//bei beenden des progs socket destroyen

			DestroyWindow(GetParent(hMain));
			return 0;
		}

		break;

	}
return 0;
}

Was ist falsch?

muss weg

#include <windows.h>

#define ID_LISTBOX		1
#define ID_BUTTON_CLOSE	2

LRESULT CALLBACK WndProc	(HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK fnListBox	(HWND, UINT, WPARAM, LPARAM) ;

TCHAR	szAppName[] = TEXT ("test") ;
WNDPROC	fnWndProc ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
					PSTR szCmdLine, int iCmdShow){
	HWND			hwnd ;
	MSG				msg ;
	WNDCLASSEX		wndclassex ;
	wndclassex.cbSize			= sizeof (WNDCLASSEX) ;
	wndclassex.style			= CS_HREDRAW | CS_VREDRAW ;
	wndclassex.lpfnWndProc		= WndProc ;
	wndclassex.cbClsExtra		= 0 ;
	wndclassex.cbWndExtra		= 0 ;
	wndclassex.hInstance		= hInstance ;
	wndclassex.hIcon			= LoadIcon (NULL, IDI_APPLICATION) ;
	wndclassex.hCursor			= LoadCursor (NULL, IDC_ARROW) ;
	wndclassex.hbrBackground	= (HBRUSH) (COLOR_BTNFACE + 1) ;
	wndclassex.lpszMenuName		= NULL ;
	wndclassex.lpszClassName	= szAppName ;
	wndclassex.hIconSm			= NULL ;
	RegisterClassEx (&wndclassex) ;
	hwnd = CreateWindowEx (NULL, szAppName, TEXT ("test"),
							WS_OVERLAPPEDWINDOW,
							CW_USEDEFAULT , CW_USEDEFAULT,
							300, 300,
							NULL, NULL, hInstance, NULL) ;
	ShowWindow (hwnd, iCmdShow) ;
	UpdateWindow (hwnd) ;
	while (GetMessage (&msg, NULL, 0, 0)){
		TranslateMessage (&msg) ;
		DispatchMessage (&msg) ;
	}
	return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){
	static	HINSTANCE	hInstance ;
	switch (message){
		case WM_CREATE :
			hInstance = ((LPCREATESTRUCT) lParam) -> hInstance ;
			CreateWindowEx (WS_EX_CLIENTEDGE | WS_EX_ACCEPTFILES, "listbox",
							TEXT ("Ok"), 
							WS_CHILD | WS_VISIBLE | LBS_DISABLENOSCROLL | LBS_STANDARD,
							10, 10,
							270, 220,
							hwnd, (HMENU) ID_LISTBOX, hInstance, NULL) ;
			CreateWindowEx (NULL, "button",
							TEXT ("Ende"), WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
							210, 240,
							75, 25,
							hwnd, (HMENU) ID_BUTTON_CLOSE, hInstance, NULL) ;
			fnWndProc = (WNDPROC) SetWindowLongPtr (GetDlgItem (hwnd, ID_LISTBOX), GWLP_WNDPROC, (LONG_PTR) fnListBox) ;
			return 0 ;
		case WM_COMMAND :
			switch (LOWORD (wParam)){
				case ID_BUTTON_CLOSE :
					SendMessage (hwnd, WM_DESTROY, 0, 0) ;
					break ;
			}
			return 0 ;
 		case WM_DESTROY :
			PostQuitMessage (0) ;
			return 0 ;
	}
	return DefWindowProc (hwnd, message, wParam, lParam) ;
}

LRESULT CALLBACK fnListBox (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){
	INT_PTR	nCnt,
			nIndex,
			nSize ;		
	char	*pszFileName = NULL;
	HDROP	hDrop ;
	switch(message){
		case WM_DROPFILES :
			hDrop = (HDROP) wParam ;
			nCnt  = DragQueryFile (hDrop, (UINT)-1, NULL, 0) ;
			for (nIndex = 0; nIndex < nCnt; ++nIndex){
				if (0 == (nSize = DragQueryFile (hDrop, nIndex, NULL, 0))){
					break ;
				}
				pszFileName = (char*) malloc ((sizeof (char) * nSize) + 1) ;
				if (DragQueryFile (hDrop, nIndex, pszFileName, nSize)){
					SendMessage (GetDlgItem (GetParent (hwnd), ID_LISTBOX), LB_ADDSTRING, 0, (long) pszFileName) ;
				}
				free (pszFileName) ;
			}
			break ;
	}
	return (CallWindowProc (fnWndProc, hwnd, message, wParam, lParam)) ;
}