How to remove annoying BEEP with RichTextBox

Question

I placed a RichTextBox control on a new form and launched the project. So the RichTextBox.Text = \"\";

Each time I press Up or Down keys I heard the annoying BEEP so

Answer 1

first we need send EM_GETOLEINTERFACE message to rich edit window - this is Retrieves an IRichEditOle object that a client can use to access a rich edit control's Component Object Model (COM) functionality.

then for retrieve an ITextServices pointer, call QueryInterface on the private IUnknown pointer returned by EM_GETOLEINTERFACE.

here exist interesting point - the IID_ITextServices not well known but need get in runtime from Msftedit.dll

from About Windowless Rich Edit Controls

Msftedit.dll exports an interface identifier (IID) called IID_ITextServices that you can use to query the IUnknown pointer for the ITextServices interface.

after we got ITextServices pointer - we simply can call OnTxPropertyBitsChange(TXTBIT_ALLOWBEEP, 0)

code example:

    if (HMODULE hmodRichEdit = LoadLibrary(L"Msftedit.dll"))
    {
        // create richedit window
        if (HWND hwndRich = CreateWindowExW(0, MSFTEDIT_CLASS, ...))
        {
            if (IID* pIID_ITS = (IID*) GetProcAddress(hmodRichEdit, "IID_ITextServices"))
            {
                IUnknown* pUnk;
                if (SendMessageW(hwndRich, EM_GETOLEINTERFACE, 0, (LPARAM)&pUnk))
                {
                    ITextServices* pTxtSrv;
                    HRESULT hr = pUnk->QueryInterface(*pIID_ITS, (void**)&pTxtSrv);
                    pUnk->Release();
                    if (0 <= hr)
                    {
                        pTxtSrv->OnTxPropertyBitsChange(TXTBIT_ALLOWBEEP, 0);
                        pTxtSrv->Release();
                    }
                }
            }
        }
    }