I need getRTF() example for win32 api richedit control [duplicate] - winapi

Question

(Sorry for my crazy English)
I want to get all the text in Rich Edit with RTF format, not plain text to a variable. I tried SendMessage() with EM_STREAMOUT to write directly Rich Edit to file, but I can't save the content to specific variables, for example LPWSTR. Please remember, only Win API, not MFC. Thanks for you help!

Answer 1

You can pass your variable to the EM_STREAMOUT callback so it can be updated as needed, eg:
DWORD CALLBACK EditStreamOutCallback(DWORD_PTR dwCookie, LPBYTE pbBuff, LONG cb, LONG *pcb)
{
std::stringstream *rtf = (std::stringstream*) dwCookie;
rtf->write((char*)pbBuff, cb);
*pcb = cb;
return 0;
}
.
std::stringstream rtf;
EDITSTREAM es = {0};
es.dwCookie = (DWORD_PTR) &rtf;
es.pfnCallback = &EditStreamOutCallback;
SendMessage(hRichEditWnd, EM_STREAMOUT, SF_RTF, (LPARAM)&es);
// use rtf.str() as needed...
Update: to load RTF data into the RichEdit control, use EM_STREAMIN, eg:
DWORD CALLBACK EditStreamInCallback(DWORD_PTR dwCookie, LPBYTE pbBuff, LONG cb, LONG *pcb)
{
std::stringstream *rtf = (std::stringstream*) dwCookie;
*pcb = rtf->readsome((char*)pbBuff, cb);
return 0;
}
.
std::stringstream rtf("...");
EDITSTREAM es = {0};
es.dwCookie = (DWORD_PTR) &rtf;
es.pfnCallback = &EditStreamInCallback;
SendMessage(hRichEditWnd, EM_STREAMIN, SF_RTF, (LPARAM)&es);

Answer 2

Using the EM_STREAMOUT message is the answer.
Here is the simplest example that I can construct to demonstrate. This will save the contents of a rich edit control to a file.
DWORD CALLBACK EditStreamOutCallback(DWORD_PTR dwCookie, LPBYTE pbBuff, LONG cb, LONG *pcb)
{
HANDLE hFile = (HANDLE)dwCookie;
DWORD NumberOfBytesWritten;
if (!WriteFile(hFile, pbBuff, cb, &NumberOfBytesWritten, NULL))
{
//handle errors
return 1;
// or perhaps return GetLastError();
}
*pcb = NumberOfBytesWritten;
return 0;
}
void SaveRichTextToFile(HWND hWnd, LPCWSTR filename)
{
HANDLE hFile = CreateFile(filename, GENERIC_WRITE, 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile == INVALID_HANDLE_VALUE)
{
//handle errors
}
EDITSTREAM es = { 0 };
es.dwCookie = (DWORD_PTR) hFile;
es.pfnCallback = EditStreamOutCallback;
SendMessage(hWnd, EM_STREAMOUT, SF_RTF, (LPARAM)&es);
CloseHandle(hFile);
if (es.dwError != 0)
{
//handle errors
}
}