An MFC application need an edit ctrl in dialog for edit Tamil language.
But I found the Tamil language does not have code page in Windows (Yes, there isn't Tamil system locale), and the Unicode option is not in my situation.
Saw someone idea, Embedding HWND into external process using SetParent
I wanna to create another application built with UNICODE option, embed its window to the dialog, but failed.
Check the MSDN, SetParent need the parent and child window in one application.
So, how can I implement it?
#MSalters
I solved it by override virtual BOOL CWinThread::PumpMessage(), force the message loop use W version API.
BOOL CtamildlgApp::PumpMessage()
{
_AFX_THREAD_STATE *pState = AfxGetThreadState();
if ( !::GetMessageW( &( pState->m_msgCur ), NULL, NULL, NULL ) )
{
// Note: prevents calling message loop things in 'ExitInstance'
// will never be decremented
return FALSE;
}
// process this message
if ( pState->m_msgCur.message != WM_KICKIDLE )
{
::TranslateMessage( &( pState->m_msgCur ) );
::DispatchMessageW( &( pState->m_msgCur ) );
}
return TRUE;
}
Then CreateWindowExW(... MSFTEDIT_CLASS ...)
Tamil is indeed harder than usual. But still there's one thing obvious: use Unicode, not MBCS. Internally, all Windows functions are Unicode. The MBCS wrappers use the current code page to translate from multi-byte encodings to UTF-16. E.g. when you call MessageBoxA("Some String"), the current code page is used to translate that into a call of MessageBoxW(L"Some String").
Now, this directly means that you cannot call MessageBoxA("Narrow Tamil String") since there's no code page to convert that into the appropriate wide string. You MUST call the Unicode function MessageBoxW("Narrow Tamil String") directly.
MFC cannot magically make this problem go away. It may provide a nicer syntax for some calls, wrapping Win32 idioms in classes, constructors and destuctors. But it can't create missing code pages out of thin air.
Related
The RichEdit control has this very annoying feature. It beeps every time the user tries to move the cursor past its "end point". For instance, you can test it with the WordPad that also implements RICHEDIT. Open it up, type in some text, then hit the Home key. If the cursor was not in the beginning of the line:
hitting Home key will move it there, but then hitting the Home key again will produce this beep.
At first glance it seemed like overriding WM_KEYDOWN and WM_KEYUP messages and blocking the situations when RICHEDIT can produce that beep was a solution ... until I actually started implementing it. Unfortunately though, it's not as simple as it sounds, as that control beeps in a LOT OF CASES! So my keystroke blocking code literally ballooned to over 300+ lines, and I still see that there are some key-presses that I either didn't account for, or worse, I might have overridden some useful behavior with. (Read below for more details.)
Then I decided to look inside the implementation of the RICHEDIT control itself. And sure enough, for instance if we look at the implementation of the Home key press, the C:\WINDOWS\SysWOW64\msftedit.dll on my Windows 10 OS, has the function called ?Home#CTxtSelection##QAEHHH#Z (or public: int __thiscall CTxtSelection::Home(int,int) demangled) at the mapped offset 0x3FC00, that is hard-coded to call the MessageBeep(MB_OK), or exactly what I'm trying to eliminate:
And if you look at the address 0x6B64FD38 in the screenshot above, there's a built-in way to bypass it, with what looks to be flag 0x800.
So having dug into msftedit.dll a little bit more, there appears to be a function called ?OnAllowBeep#CTxtEdit##QAEJH#Z (or public: long __thiscall CTxtEdit::OnAllowBeep(int) demangled) that can modify this flags:
After a bit more research I found out that there are COM interfaces built into RICHEDIT control, such as ITextServices and ITextHost that reference that flag as TXTBIT_ALLOWBEEP in ITextServices::OnTxPropertyBitsChange method.
Unfortunately though, I can't seem to find the way how I can directly change that TXTBIT_ALLOWBEEP flag (COM is not my forte.) I tried looking into implementing ITextHost, but it has a lot of virtual methods that have nothing to do with what I'm trying to achieve that I don't know how to implement.
Does anyone have any idea how to clear that TXTBIT_ALLOWBEEP flag?
PS. Here's why I didn't go the route of overriding key-presses:
Just to give you an example. Say, if I override the VK_HOME key press. I need to make sure that the cursor is not at the beginning of the line, but also that there's no selection. Yet, I need to make sure that Ctrl key is not down in a situation when the cursor is at the very top of the window. Then the same with the Shift key, and I'm not even sure what Alt does with it ... and so forth. Oh, and this is just the Home key. There's also Up, Down, Left, Right, PageUp, PageDown, End, Delete, Backspace. (And that's what I was aware of. There may be more, plus I'm not even talking about IME or other keyboard layouts, etc.) In other words, it becomes a mess!
So, eventually I realized that anticipating a keystroke is not the way to go.
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 with TXTBIT_ALLOWBEEP mask
code example:
#include <textserv.h>
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();
}
}
}
}
}
I created a dialog MainDialog.cpp with 2 edit controls whose IDs are IDC_EDITCONTROL_A and IDC_EDITCONTROL_B, and have variables defined as m_editControlA and m_editControlB, respectively.
Also, I have 2 buttons whose IDs are IDC_MFCBUTTON_KEY_X and IDC_MFCBUTTON_KEY_Y, and variables are m_buttonKeyX and m_buttonKeyY, respectively.
Below is the code in the source file
#include "afxdialogex.h"
IMPLEMENT_DYNAMIC(CMainDialog, CDialogEx)
CMainDialog::CMainDialog(CWnd* pParent): CDialogEx(IDD_MAIN_DIALOG, pParent)
{
}
CMainDialog::~CMainDialog()
{
}
void CMainDialog::DoDataExchange(CDataExchange* pDX)
{
CDialogEx::DoDataExchange(pDX);
DDX_Control(pDX, IDC_EDITCONTROL_A, m_editControlA);
DDX_Control(pDX, IDC_EDITCONTROL_B, m_editControlB);
DDX(Control(pDX, IDC_MFCBUTTON_KEY_X, m_buttonKeyX);
DDX(Control(pDX, IDC_MFCBUTTON_KEY_Y, m_buttonKeyY);
}
BEGIN_MESSAGE_MAP(CMainDialog, CDialogEx)
ON_EN_CHANGE(IDC_EDITCONTROL, &CMainDialog::OnEnChangeEditA)
ON_BN_CLICKED(IDC_MFCBUTTON_KEY_X, &CMainDialog::OnBnClickedButtonX)
ON_BN_CLICKED(IDC_MFCBUTTON_KEY_Y, &CMainDialog::OnBnClickedButtonY)
END_MESSAGE_MAP()
void CMainDialog::OnBnClickedButtonX()
{
m_editControlA.SetWindowTextW(_T("X")); // test
}
void CMainDialog::OnBnClickedButtonX()
{
m_editControlA.SetWindowTextW(_T("Y")); // test
}
I am trying to understand how I can have each button send their respective character (i.e. X or Y in this example) to the selected edit control if one is selected. Essentially, I would like to simulate keyboard input.
I have read the docs about how to simulate keyboard events and also the sendMessage but I could not understand how to implement it since my C++ knowledge is very basic. Also, following my previous question I have found that the GetFocus would be useful but still my main issue currently is sending the input.
Any example code or useful link could be very useful for me to learn how I can simulate a keyboard input inside an app.
The characters are sent from the OS to the edit controls using the WM_CHAR message.
In reality it is a bit more complex than that, but you do not need to emulate the entire WM_KEYUP WM_KEYDOWN message sequence, since its end result is to generate a WM_CHAR message.
You can use CWnd::PostMessage to send characters directly to your edit controls, even when they do not have the focus.
You have probably already found the documentation for WM_CHAR here: https://msdn.microsoft.com/fr-fr/library/windows/desktop/ms646276(v=vs.85).aspx
oops.. excuse my french, ths english doc is here
https://msdn.microsoft.com/en-us/library/windows/desktop/ms646276(v=vs.85).aspx
(just changing the fr-fr to en-us does the trick, it probably works for all other languages, neat!
wParam holds the character you want to send. Either an plain ASCII character, or one of the VK_ constants... I suggest you use the unicode version WM_CHARW, as most windows software uses unicode nowadays. The notation for wide chars is either L'X' or _T('X'), the unicode (UTF-16) character type is wchar_t.
lParam contains other keystroke details, 0 should be fine for what you want to do.
to send X, simply call
m_editControlA.PostMessage(WM_CHAR, _T('X'));
When using the _T() notation, the character (or string) literal between the parenthesis will be automatically converted to the right character width for your app's unicode setting (you should set that to UNICODE, since that's what the OS is using, and is also the only valid encoding for Windows CE, for example, and you should get used to manipulating this type.
the _T() macros and _t* overrides for almost all C library functions operating on strings are defined in tchar.h, which is included by Visual Studio in stdafx.h. Under MFC, you'll mostly use CString, but it's good to know where these things are.
[EDIT] When you get that running, you should start playing with WM_KEYDOWN. You will discover that PostMessage(WM_CHAR, VK_ESCAPE) directly to your dialog does not close it, while a PostMessage(WM_KEYDOWN, VK_ESCAPE) does. And that m_editBox.PostMessage(WM_KEYDOWN, _T('X')) will send a lower key 'x' to your edit box. But that's another topic to ivestigate.
Have fun with MFC!
For your last question:
Sure, but it gets a bit more complicated, as your button will gain focus, as soon as you click on it. You'd have to create handlers for EN_SETFOCUS for eeach of your edit boxes, and add a CWnd* data member to keep track of the last edit box that had focus.
Your EN_SETFOCUS handlers should look something like this
void CdlgDlg::OnEnSetfocusEdit1()
{
m_pWndLastFocus = &m_edit1;
}
Don't forget to set the pointer to NULL in your constructor and to chjeck it's valid before calling m_pWndLastFocus->PostMessage() though.
The way to synthesize input in MFC is by using the SendInput method.
First let me say that I've been searching for a solution for couple of days now...
I'm trying to get selected item for ListBox. This is my code:
CListBox * pList1 = (CListBox *)GetDlgItem(IDC_LIST1);
CString ItemSelected;
// Get the name of the item selected in the Sample Tables list box
// and store it in the CString variable declared above
pList1->GetText(pList1->GetCurSel(), ItemSelected);
MessageBox(ItemSelected, "TEST", MB_OK);
Now when i try this i get an error message saying "The Parameter is incorect"
Your code looks OK except error handling. Also MessageBox parameters look incorrect. The first parameter should be of type HWND. I believe that this is the root cause of your problems. Use MFC standard AfxMessageBox instead:
CListBox * pList1 = (CListBox *)GetDlgItem(IDC_LIST1);
int nSel = pList1->GetCurSel();
if (nSel != LB_ERR)
{
CString ItemSelected;
pList1->GetText(nSel, ItemSelected);
AfxMessageBox(ItemSelected);
}
If the CListBox is in single selection mode, the CListBox::GetCurSel will return the selected index.
If the CListBox is in multi-selection mode, you should use CListBox::GetSelItems which will return a list of indices.
You cannot mix'n'match the functions.
And always check return codes (as others already wrote).
If You already have a data member MyList(of classCListBox) :
int nSel = MyList.GetCurSel();
CString ItemSelected;
if (nSel != LB_ERR)
{
MyList.GetText(nSel, ItemSelected);
}
CWnd class has a MessageBox function which does not need a HWND parameter. But yes, AfxMessageBox is a little bit more easier to use and can be called anywhere in the MFC code without having a CWnd-derived object. And a beside note: if call a WinAPI function inside MFC code (not needed here, but possible in other cases) it's good to prepend it with scope resolution operator in order to avoid any confusion, mistake and/or name conflict (e.g. ::MessageBox...).
One possible cause for "invalid parameter" error in OP code is that it uses an ANSI string literal ("TEST") in a UNICODE build configuration. This case, must use an UNICODE string literal (L"TEST") or a little bit better, use _T macro (_T("TEST")) that makes it possible to build in both ANSI and UNICODE configurations.
I created two wxTextCtrl. One for log in (loginTxt) and another for password (pwdTxt) and both have readable default message.
I also installed wxEVT_LEFT_DOWN event so that when user click on either loginTxt or pwdTxt the default message will be set to empty string
Is it possible to set wxTE_PASSWORD style to the pwdTxt later? If it's possible, how can I do that?
I read wx.chm and it say,
"Note that alignment styles (wxTE_LEFT, wxTE_CENTRE and wxTE_RIGHT) can be changed dynamically after control creation on wxMSW and wxGTK. wxTE_READONLY, wxTE_PASSWORD and wrapping styles can be dynamically changed under wxGTK but not wxMSW. The other styles can be only set during control creation.".
I am writing my application on MS Windows with wxWidgets 2.9.3
You cannot change it later on Windows, since Microsoft's control does not support that. If you really need to, I suggest creating 2 different controls and show/hide the appropriate one.
Windows-only solution, probably will be useful:
void Sample::OnBUTTONClick( wxCommandEvent& event )
{
#if defined(__WXMSW__)
HWND hWnd = (HWND)m_Text->GetHandle();
SendMessage(hWnd, EM_SETPASSWORDCHAR, 0x25cf, 0); // 0x25cf is ● character
m_Text->Update();
#endif
}
Is it possible to manipulate .net controls from native code? Particularly, I'd like to set the text of a TextBox from some native code. I want it done this way to keep the business logic separated from the user interface, but it is precisely the native code which only knows how to appropriately format the data (some bytes received within a protocol).
I know I could get the window handle through the Handle property, but once there, how would I call the desired method?
Is string handling my only option? Should the native code build up the message to be displayed on the control?
The "native" way of setting the text on a textbox is to send the textbox the WM_SETTEXT message:
// handle is initialized from TextBox::Handle
PostMessage(handle, WM_SETTEXT, 0, _T("Some text"));
Read up on PostMessage and SendMessage, too. Depending on how you allocate and build up the text, you may need to use SendMessage to avoid deallocating prematurely.
If you want to keep your business logic separated from your user interface, and some of your business logic is in native code, then it would be a really good idea not to change any GUI content from the native code directly, because it is exactly the opposite of what you want to achieve. Better try to write some kind of wrapper method in C++/CLI to call the native data format routine from there, making it available for your use in your GUI code.
If you really want to make calls from native code to managed code, you can declare a (native!) static method in C++/CLI which calls a managed method. You can pass a function pointer to such a method to a lower layer of your program (for example, your native C++ layer), which can be called from there.
Something along the lines of:
// the native code layer:
// "Callbacks.h"
void (*_myNativeCallback)();
void InitCallback(void (*myNativeCallback)())
{
_myNativeCallback=myNativeCallback;
}
// now you can use _myNativeCallback within your native code
// the C++/CLI layer:
#include "Callbacks.h"
//...
static void MyNativeCallback()
{
ManagedClass::StaticMethod();
}
InitCallback(MyNativeCallback);
In ManagedClass::StaticMethod, you have access to your .NET code and you should not have any problems to manipulate a TextBox of any form you can reach from there. If you have to convert a native string to a System::String, you may find this code snippet helpful:
inline System::String StdToSysString(const std::string &s)
{
return gcnew System::String(s.c_str());
}
And the other way round (Ansi code page assumed):
inline std::string SystemToStdString(System::String ss)
{
using namespace System::Runtime::InteropServices;
const char* chars =
(const char*)(Marshal::StringToHGlobalAnsi(ss)).ToPointer();
std::string s = chars;
Marshal::FreeHGlobal(System::IntPtr((void*)chars));
return s;
}