ich habe ine EDITBOX mit folglenden eigenschaften: WS_VISIBLE|WS_CHILD|WS_BORDER|ES_AUTOHSCROLL

und wennn ich in der Edit box enter drücke wird eine function aufgerufen,d as fucntioneir ganz gut, nur das problem ist, dieses Geräusch was kommt, dieses sim

wie kann ich dieses geräusch bei enterdrücken deaktivieren?

wenn ich return 0;
break;
etc eingäbe, wird es trotzt augeführt

LRESULT CALLBACK MsgControl (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    char text[255]; //text von hMsg
    char txt[255];
    switch(msg)
    {
        case WM_KEYDOWN :
            if (wParam == VK_RETURN)
            {
                SendMessage(hMsg, WM_GETTEXT, sizeof(text), (ULONG)text);
                SendMessage(hChat, WM_GETTEXT, sizeof(txt), (ULONG)txt);
                send_msg(text, txt);
            }
            break;
        default :
            return CallWindowProc ((WNDPROC) PrevhMsg, hwnd, msg, wParam, lParam);  
    }
    return 0;
}

HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_HREDRAW | CS_VREDRAW;;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, (LPCTSTR)IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, (LPCTSTR)IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Sintima Multi-Chnnel Support System",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           610,                 /* The programs width */
           400,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

LRESULT CALLBACK EditProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
	switch(msg)
	{
		case WM_CHAR:
		case WM_KEYDOWN:
			if( wParam == VK_RETURN )
				return 0;
		break;
	}

	return CallWindowProc( oldEditProc, hWnd, msg, wParam, lParam );
}

is das calback

und hier der ganze code :

#include <windows.h>
#include "SinSupport_private.h"
#include<Richedit.h>
/* ::::::: controlls IDs :::::::: */

const int TXT_CHAT = 870;
const int TXT_MSG = 535;
const int BTN_SEND = 90;
const int BTN_CONNECT = 100;
const int CMB_CHANNEL = 54;
const int BTN_DICONNECT = -100;

/* ::::::::::::: CONTROLLS HWNDs :::::::::::: */

static HWND hChat;
static HWND hMsg;
static HWND hSend;
static HWND hChannel;
/* SUBCLASSING VARS */
static LONG_PTR PrevhMsg;
static LONG_PTR PrevhChat;
static LONG_PTR PrevhChannel;

/*  CAllBACK FÜR WINDOW  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
/* CALLBACK FÜR hCHAT */
LRESULT CALLBACK ChatControl (HWND, UINT, WPARAM, LPARAM);
/* CALLBACK FÜR hMsg */ 
LRESULT CALLBACK MsgControl (HWND, UINT, WPARAM, LPARAM);
/* CHANNEL */
LRESULT CALLBACK ChannelControl (HWND, UINT, WPARAM, LPARAM);
/* SEND FUCNTION */
int send_msg(char *, char *);
/* ADD TEXTFUCNTION */
/*  Make the class name into a global variable  */
char szClassName[ ] = "support";

int WINAPI WinMain (HINSTANCE hThisInstance,
                    HINSTANCE hPrevInstance,
                    LPSTR lpszArgument,
                    int nFunsterStil)

{
    HINSTANCE insChat =  insChat = LoadLibrary("RichEd32.dll"); /* LOAD RICHTEXT CONTROLL DLL */
    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_HREDRAW | CS_VREDRAW;;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, (LPCTSTR)IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, (LPCTSTR)IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default color as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "Sintima Multi-Chnnel Support System",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           610,                 /* The programs width */
           400,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    FreeLibrary(insChat);
    return messages.wParam;
}

/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    char txt[256]; // Vtext of hMsg
    char text[256];
    int index_design_0;
    int index_code_0;
    int index_info_0;
    int index_info_1;
    int index_support_0;
    switch (message)                  /* handle the messages */
    {
        case WM_CREATE:
            /* ::::: DIE COMBOBOX UND BUTTON ::: */
            hChannel = CreateWindowEx(WS_EX_CLIENTEDGE, "ComboBox", "", WS_VISIBLE|WS_CHILD|CBS_DROPDOWNLIST|CBS_HASSTRINGS,
                100,
                10,
                200,
                500,
                hwnd, (HMENU)CMB_CHANNEL, ((LPCREATESTRUCT) lParam) -> hInstance, 0);
            PrevhChannel = SetWindowLongPtr (hChannel, GWLP_WNDPROC, (LONG_PTR) ChannelControl);
            CreateWindowEx(WS_EX_CLIENTEDGE,"Button",
                                  "Verbinden",
                                  WS_CHILD | WS_VISIBLE,
                                  310, // x-pos
                                  10, //y-pos
                                  100, // width
                                  25, //height
                                  hwnd, (HMENU)BTN_CONNECT, ((LPCREATESTRUCT) lParam) -> hInstance, NULL);
            CreateWindowEx(WS_EX_CLIENTEDGE,"Button",
                                  "Trennen",
                                  WS_CHILD | WS_VISIBLE,
                                  415, // x-pos
                                  10, //y-pos
                                  100, // width
                                  25, //height
                                  hwnd, (HMENU)BTN_DICONNECT, ((LPCREATESTRUCT) lParam) -> hInstance, NULL);

             /* ::: Chat Control (RichText) */
             hChat = CreateWindowEx(WS_EX_CLIENTEDGE, "RichEdit", "", 
                 WS_VISIBLE|WS_CHILD|WS_VSCROLL|ES_MULTILINE|ES_READONLY|ES_AUTOVSCROLL, // style
                 10, // x -Position
                 40, // y-Postiotns
                 580,  // länge
                 290, // höhe
                 hwnd, (HMENU)TXT_CHAT, ((LPCREATESTRUCT) lParam) -> hInstance, 0);
                SendMessage(hChat, EM_SETEVENTMASK, 0, ENM_LINK);
             PrevhChat = SetWindowLongPtr (hChat, GWLP_WNDPROC, (LONG_PTR) ChatControl);
             /* ::: MSG Control (EditBox) */
             hMsg = CreateWindowEx(WS_EX_CLIENTEDGE, "Edit", "", 
                 WS_VISIBLE|WS_CHILD|WS_BORDER|ES_AUTOHSCROLL, // style
                 10, // x -Position
                 335, // y-Postiotns
                 510,  // länge
                 25, // höhe
                 hwnd, (HMENU)TXT_MSG, ((LPCREATESTRUCT) lParam) -> hInstance, 0);
                 /* CALLBACK */
             PrevhMsg = SetWindowLongPtr (hMsg, GWLP_WNDPROC, (LONG_PTR) MsgControl);
             /* ::: Button Send Controll ::: */
             hSend = CreateWindowEx(WS_EX_CLIENTEDGE,"Button",
                                  "Send",
                                  WS_CHILD | WS_VISIBLE,
                                  525, // x-pos
                                  335, //y-pos
                                  65, // width
                                  25, //height
                                  hwnd, (HMENU)BTN_SEND, ((LPCREATESTRUCT) lParam) -> hInstance, NULL);
            /* SEND MESSAGES */
            index_design_0 = SendMessage(hChannel, CB_ADDSTRING, 0, (LPARAM)"Design Channel");
            index_code_0 = SendMessage(hChannel, CB_ADDSTRING, 0, (LPARAM)"Programmierer Channel");
            index_info_0 = SendMessage(hChannel, CB_ADDSTRING, 0, (LPARAM)"Info Channel (allgemein)#1");
            index_info_1 = SendMessage(hChannel, CB_ADDSTRING, 0, (LPARAM)"Info Channel (allgemein) #2");
            index_support_0 = SendMessage(hChannel, CB_ADDSTRING, 0, (LPARAM)"Techn. SupportChannel ");
            SetFocus(hMsg);
             break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
        case WM_COMMAND:
            if (wParam == BTN_SEND)
            {
                SendMessage(hMsg, WM_GETTEXT, sizeof(text), (ULONG)text);
                SendMessage(hChat, WM_GETTEXT, sizeof(txt), (ULONG)txt);
                send_msg(text, txt); 
            }
            break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
        case WM_PAINT:
            PAINTSTRUCT ps;
            HDC         hDC;
            hDC = BeginPaint(hwnd, &ps);
            {
                SetBkMode(hDC,TRANSPARENT);// background color
                TextOut(hDC, 10, 12, "Channel :", sizeof("Channel:"));  // Text asugben 
            }
            EndPaint(hwnd, &ps);
            break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
        case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/          
        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }
    return 0;
}

/* :::::::::::::::::::: CALLBACK FÜR hChat :::::::::: */
LRESULT CALLBACK ChatControl (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    static HMENU hMenu; // PopUp menu
    POINT  point; // Position
    int select;
    switch(msg)
    {
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/ 
        case WM_CONTEXTMENU:
            hMenu = CreatePopupMenu ();    
            InsertMenu (hMenu, 0, MF_BYPOSITION, 0, "Kopieren");
            POINTSTOPOINT (point, lParam);
            if ((point.x == -1) && (point.y == -1))
            {
                point.x = point.y = GetSystemMetrics (SM_CXEDGE);
                ClientToScreen (hwnd, &point); // Die Koordinaten auf unser Fenster legen 
            }
            select = (int) TrackPopupMenu (hMenu, TPM_CENTERALIGN|TPM_LEFTBUTTON|TPM_RETURNCMD, point.x, point.y, 0, hwnd, 0);
            if (select == 0)
            {
                // Copy to clipboard    
            }
            break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/ 
        case WM_NOTIFY:
                if (wParam == EN_LINK)
                {
                MessageBox(NULL, "dfsdf", "dfsdf", MB_OK);
                ShellExecute(hChat, "open", "http://www.Meine-Hompage.de/cpp", NULL,NULL,SW_SHOWDEFAULT);
                }  
            break;
/*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/ 
        case WM_DESTROY:
            DestroyMenu (hMenu);
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        default :    
        return CallWindowProc ((WNDPROC) PrevhChat, hwnd, msg, wParam, lParam);     
    }
    return 0;
}

/* :::::::::::::::::::: CALLBACK FÜR hMsg :::::::::: */
LRESULT CALLBACK MsgControl (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    char text[255]; //text von hMsg
    char txt[255];
    switch(msg)
    {
        case WM_CHAR:
        case WM_KEYDOWN:
            if (wParam == VK_RETURN)
            {
                SendMessage(hMsg, WM_GETTEXT, sizeof(text), (ULONG)text);
                SendMessage(hChat, WM_GETTEXT, sizeof(txt), (ULONG)txt);
                send_msg(text, txt);
                return 0;
            }
            break;
        default :
            return CallWindowProc ((WNDPROC) PrevhMsg, hwnd, msg, wParam, lParam);  
    }
    return 0;
}

/* ::::::::::::::::::: CALLBACK FÜR hCHANNEL ::::::::: */

LRESULT CALLBACK ChannelControl (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {

    default:
       return CallWindowProc ((WNDPROC) PrevhChannel, hwnd, msg, wParam, lParam);       
    }
    return 0;
}

/* ::::::::::::::::::::::::::::::::::::::::::::::: FUNCTIONEN :::::::::::::::::::::::::::::::::: */

/*::: SEND FUCNTION ::::*/

int send_msg(char * text, char * txt)
{
    /* Formatierung vorbereiten */
    CHARFORMAT format;
    format.cbSize = sizeof(CHARFORMAT);
    format.dwMask  = CFM_COLOR;
    format.crTextColor = RGB(99, 99, 99);
    format.dwEffects = CFE_BOLD;
    /* Den Text ausgäben */
    SendMessage(hMsg, WM_SETTEXT, 0, (ULONG)""); // Textfiel von hMsg leeren
    SendMessage(hChat, WM_SETTEXT, 0, (ULONG)strcat(strcat(txt, text), "\r\n")); // text hinzufügen
    SendMessage(hChat, EM_SETSEL, (WPARAM)sizeof(txt)-1, (LPARAM)(strlen(txt)-1)+(strlen(text)-1)); // text auswählen
    SendMessage(hChat, EM_SETCHARFORMAT, SCF_SELECTION, (LPARAM)&format); // Farbe setzen
    SendMessage(hChat, EM_SCROLL, SB_PAGEDOWN, 0); // Scrollen nach unten
    SetFocus(hMsg); // Focus setzen
    SendMessage(hChat, EM_AUTOURLDETECT, 1, 0);
    return 0;    
}

Du fängst ALLE WM_CHAR Nachrichten ab. Der code unter "default" wird ja nie ausgeführt sondern nachdem break und verlassen des Switchs gibst du dnan am ende der funktion 0 zurück. machs einfach so dann funzts auch

LRESULT CALLBACK MsgControl (HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    char text[255]; //text von hMsg
    char txt[255];

    switch(msg)
    {
        case WM_CHAR:
        case WM_KEYDOWN:
            if (wParam == VK_RETURN)
            {
                SendMessage(hMsg, WM_GETTEXT, sizeof(text), (ULONG)text);
                SendMessage(hChat, WM_GETTEXT, sizeof(txt), (ULONG)txt);
                send_msg(text, txt);
                return 0;
            }
            break;

    }
    return CallWindowProc ((WNDPROC) PrevhMsg, hwnd, msg, wParam, lParam); 
}