i wanna make a program runs in the background and shows an icon in notification area of taskbar. I'm using win32. What api should i use? Do you know any good tutorials?
To make a program run in the background, you either add it as a service or make it "unavailable" to shutdown (for instance, hide the window for the program). To add an icon in the toolbar you use winapi. Call Shell_NotifyIcon and pass in a NOTIFYICONDATA structure
This should be defined somewhere
enum TrayIcon {
ID = 13, CALLBACKID = WM_APP+1
};
Also, in the below code the hWnd is a HWND, which is the window that you want to associate with the notification icon. This HWND's wndProc will receive the messages for the icon.
Notes:
the NIF_ICON flag makes the hIcon valid in the NOTIFICATIONICONDATA structure. So if you don't want to have an icon, don't specify it.
the NIF_MESSAGE flag makes the uCallbackMessage valid. If you don't want to handle any messages, don't specify this flag.
You have to remove the icon before you shut down your program, or it will get stuck there until you hover over it
At startup of your computer, Shell_NotifyIcon may have some difficulties to succeed. I can't find the reference for it, but I know I have read it somewhere.. So, when not successful, don't assume that it will not work at all - just try again.
With this said, this is how you add, remove and handle the messages for the tray icon
To add the icon
// in HICON hIcon: this is the icon you want as the image in the tray
NOTIFYICONDATA nid;
nid.cbSize = sizeof(NOTIFYICONDATA);
nid.hWnd = hWnd;
nid.uID = ID;
nid.uFlags = NIF_ICON | NIF_MESSAGE;
nid.hIcon = hIcon;
nid.uCallbackMessage = /*TrayIcon::*/CALLBACKID;
Shell_NotifyIcon(NIM_ADD, &nid);
To remove the icon
NOTIFYICONDATA nid;
nid.cbSize = sizeof(NOTIFYICONDATA);
nid.hWnd = hWnd;
nid.uID = /*TrayIcon::*/ID;
Shell_NotifyIcon(NIM_DELETE, &nid);
Handling the messages for the icon
LRESULT wndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam){
switch (msg){
// ...
case /*TrayIcon::*/CALLBACKID:
{
// here, you handle the messages for your tray icon
}
break;
// ...
}
}
http://www.winprog.org/tutorial/ is good for learning winapi and basically how Windows apps work. For the tray icon, use Shell_NotifyIcon. You will need a window, and a message loop for this.
CSystemTray works well from coeproject.
It is a wrapper around Shell_NotifyIcon.
Related
This is a Windows Desktop Application project created by Visual Studio.
I have a Dialog resource created from the Resource View that has a Static Text.
I'm using this dialog in order to show errors to the user:
DialogBox(hInst, MAKEINTRESOURCE(IDD_MY_MESSAGE_BOX), hWnd, MyMessageBoxProc);
The reason I'm using a DialogBox is that I need it to stop the code execution, because the next line of code will close the application I mean the user should be aware of the error message before application exits. I know a way to change the Static Text:
HWND myMessageBox = CreateDialog(hInst, MAKEINTRESOURCE(IDD_MY_MESSAGE_BOX), nullptr, MyMessageBoxProc);
HWND staticText = GetDlgItem(myMessageBox, IDC_STATIC);
SetWindowText(staticText, L"Text changed.");
But that approach doesn't stop code execution.
Since it's a Windows Desktop Application project I cannot create MFC classes and try the following approach:
// Find the Static Text.
// If called from within MyMessageBox class.
CWnd *staticText = GetDlgItem(IDC_STATIC);
staticText->SetWindowText("Text changed.");
// If called from elsewhere.
MyMessageBox myMessageBox;
CWnd *staticText = myMessageBox.GetDlgItem(IDC_STATIC);
staticText->SetWindowText("Text changed.");
So what would be a workaround in order to change the Static Text using a DialogBox without the need of MFC classes or even another approach that allows me to change the Static Text and still stop code execution like a DialogBox.
Just change the text in your window procedure (MyMessageBoxProc) by handling WM_INITDIALOG message. If you wish to supply the text to the dialog, then create it using DialogBoxParam instead, which is then accessible via the lParam parameter.
e.g.
INT_PTR MyMessageBoxProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
if (message == WM_INITDIALOG) {
HWND hCtrl = GetDlgItem(hWnd, IDC_STATIC);
SetWindowText(hCtrl, reinterpret_cast<LPCTSTR>(lParam));
}
return FALSE;
}
The creation would be something like:
LPCTSTR text = _T("Text changed.");
DialogBoxParam(hInst, MAKEINTRESOURCE(IDD_MY_MESSAGE_BOX), hWnd, MyMessageBoxProc,
reinterpret_cast<LPARAM>(text));
Note that there is a standard message box that ships with windows, which you may want to use instead of writing your own. That's available via the function MessageBox
About
I am trying to build a custom mouse input for Unity that gets the data directly from the HID. I do this because I want to try if there is any difference (when using my own custom mouse input) to the Unity API that gives me raw mouse input.
Also I need to say that everything I am doing right now does not happen within Unity. I want to build an C++ application and then pass the data to Unity (that's not a part of this question).
This link (MSDN High-Definition Mouse Movement) shows that there are three different types of messages I can use. Due to I need so called "High-Definition Mouse Movement" I need to go with WM_INPUT.
This message can be caught with the WinProc handler as the documentation says. Within that callback the raw mouse data can be accessed. This is what I want to achieve and where I need help.
My current approach
The documentation (link above) gives me this example to register the mouse:
RAWINPUTDEVICE Rid[1];
Rid[0].usUsagePage = HID_USAGE_PAGE_GENERIC;
Rid[0].usUsage = HID_USAGE_GENERIC_MOUSE;
Rid[0].dwFlags = RIDEV_INPUTSINK;
Rid[0].hwndTarget = gameWindowHandle;
regDeviceDone = RegisterRawInputDevices(Rid, 1, sizeof(Rid[0]));
The following two lines were modified by me:
Rid[0].hwndTarget = gameWindowHandle;
There I define the Unity window as target. gameWindowHandle is set by EnumWindows.
The other line I changed is the last one due to there is a syntax error (missing parenthesis).
As far as I understood the documentation right this should be it. Now the following callback should be called when there are WM_INPUT messages sent to the Unity window.
LRESULT CALLBACK WindowProc(
_In_ HWND hwnd,
_In_ UINT uMsg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
) {
printf("%d", uMsg);
switch (uMsg) {
case WM_INPUT:
UINT dwSize = 40;
static BYTE lpb[40];
GetRawInputData((HRAWINPUT)lParam, RID_INPUT,
lpb, &dwSize, sizeof(RAWINPUTHEADER));
RAWINPUT* raw = (RAWINPUT*)lpb;
if (raw->header.dwType == RIM_TYPEMOUSE)
{
int xPosRelative = raw->data.mouse.lLastX;
int yPosRelative = raw->data.mouse.lLastY;
printf("X: %d, Y: %d", xPosRelative, yPosRelative);
}
break;
}
return NULL;
}
My problems
The first problem I have is that calling this
regDeviceDone = RegisterRawInputDevices(Rid, 1, sizeof(Rid[0]));
does not return true as it should. Instead it returns false and GetLastError gives me error 87 (after googling this I found out it has to do with wrong parameters).
The documentation says to do so but unfortunately it does not work the way I do it.
Another problem is how to keep the application alive. After registering the device I need to wait for the callbacks to trigger (if they would work). How can I achieve that the application does nothing than waiting for the callbacks?
Is my approach even reasonable or am I doing completely wrong and have to use different APIs?
Your approach is wrong. First, RawInput requires Window. A Window under your control with your own WndProc. Hence in your C++ library, you should define a window procedure. Start a thread. In this thread register window class with that procedure. After you succeed in registering your class, create HWND_MESSAGE window, register your devices and enter a while GetMessage... DispatchMessage loop. This should be done in a separate thread. In your window procedure you must now catch WM_INPUT messages. Enjoy.
I would like to know if its possible to specify a WndProc for a Child Window created by CreateWindowEx.
I have created a Window Class, the Main Window, the Window Procedure and a Message Loop already. The code works and I decided to keep it out for the clarity of my question.
This is my Window Proc, so far:
LRESULT CALLBACK WndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
// Creation of the Win32 Window
case WM_CREATE:
// Add an Edit Field
CreateWindowEx(
WS_EX_CLIENTEDGE,
"EDIT",
"",
WS_CHILD | WS_VISIBLE,
5, 5, 200, 24,
hwnd,
(HMENU)100,
g_Instance, // Comming from WinMain
NULL
);
return DefWindowProc(hwnd, uMsg, lParam, wParam);
case WM_KEYDOWN:
// Track key presses on the edit field
std::cout << "The key with the code " << wParam << " was pressed." << std::endl;
return 0;
case WM_PAINT:
// Some painting code...
return DefWindowProc(hwnd, uMsg, lParam, wParam);
default:
return DefWindowProc(hwnd, uMsg, lParam, wParam);
}
}
I expected key presses on the child Edit Field that I created to throw a WM_KEYDOWN message, but they dont! The keys just get added to the Edit Field in my Window but do not cause a WM_KEYDOWN message.
It seems that the created Edit Window does not use my WndProc. How can I change that?
Your WndProc don't get WM_KEYDOWN messages because, if the user is typing inside the edit control, it means that it has the focus (not your window), so they are sent to the edit control window proc, not yours. However, the edit control window proc will send notifications to your WndProc (his parent window proc).
So, if you only want to react to the user changing the content of your child edit control, you don't need another window procedure. Your current WndProc will receive EN_CHANGE notification code through a WM_COMMAND message.
See https://msdn.microsoft.com/en-us/library/windows/desktop/bb761676(v=vs.85).aspx
If you really want to catch WM_KEYDOWN messages, you need to subclass the edit control, like this:
OldWndProc = (WNDPROC)SetWindowLongPtr (hButton, GWLP_WNDPROC, (LONG_PTR)NewWndProc);
You also need to define a new windows procedure (the NewWndProc), that should handle WM_KEYDOWN message (and any other message you want to handle). You also need to call OldWndProc as you would call DefWndProc in a standard WndProc, unless you want to prevent the edit control to do its normal processing.
For details on subclassing, see https://msdn.microsoft.com/en-us/library/windows/desktop/bb773183(v=vs.85).aspx
Edit
Responding to OP comment here.
If your window is a dialog box, you should be notified of enter key, in your WndProc:
case WM_COMMAND:
if(wParam == IDOFDEFBUTTON || wParam == IDOK) ...
See https://support2.microsoft.com/Default.aspx?scid=kb;en-us;Q102589
To be honest, I never took the time to understand what a dialog box really is. But if I recall correctly, you can get your window to get theses special notifications by calling IsDialogMessage in your message pump:
if(!IsDialogMessage(hWnd,&msg)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
For interesting information about IsDialogMessage, see http://blogs.msdn.com/b/oldnewthing/archive/2012/04/16/10293933.aspx
If this doesn't give you enough control, you probably have to subclass the edit control.
Your call to CreateWindowsEx creates a new window with "EDIT" wnd class having its own Window procedure. You need a new WndProc and set it to the newly created window (whose handle is returned by CreateWindowEx) via SetClassLong function
As I found out by searching, it is not possible to create a MessageBox() with center-aligned text.
So is there some simple alternative providing the MessageBox() functionality (including program wait for closing/accepting the box) that has an option to center-align the text?
Thanks for suggestions/examples.
PS: On Windows7+, using C++ Windows API (compiled in MS Visual Studio 2012)
EDIT:
Some useful tips:
1) Express version of Visual Studio does NOT have a resource editor/file create option:
You do have a Visual Studio "higher" than express - How to: Add a
Resource File
You have just Express version :
How to
add a resource editor for Express version
Free editor
ResEdit
This MSDN forum page contains some other useful tips like:
From the 'solution explorer', right-click the *.rc file and select
'open with..', then select 'source code (text) editor' from the list.
You might want to 'set as default' to save you repeating those
intitial steps. Once done, you should be able to manually edit the
resource script within Express.
Free XN Resource Editor
2) Visual Studio C++ how to display a dynamic message (i.e., string) in my About box?
As I found out by searching, it is not possible to create a MessageBox() with center-aligned text.
It is not possible to create a center-aligned MessageBox() dialog, as the API does not expose an option for that. But it is possible to manipulate the standard MessageBox()` dialog with some slight trickery to force it to be center-aligned.
Use SetWindowsHookEx() to create a WH_CBT hook for the thread that is calling MessageBox() (no DLL needed). The hook callback allows you to discover the HWND of the dialog that MessageBox() creates. With that, you can manipulate it however you want. In this case, you can use FindWindowEx() to get the HWND of the STATIC control for the dialog's text and then apply the SS_CENTER style to it using SetWindowLong(). For example:
LRESULT CALLBACK CenterMsgBoxTextProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode == HCBT_ACTIVATE)
{
HWND hDlg = (HWND) wParam;
HWND hTxt = FindWindowEx(hDlg, NULL, TEXT("STATIC"), NULL);
if (hTxt)
SetWindowLong(hTxt, GWL_STYLE, GetWindowLong(hTxt, GWL_STYLE) | SS_CENTER);
}
return CallNextHookEx(NULL, nCode, wParam, lParam);
}
HHOOK hHook = SetWindowsHookEx(WH_CBT, (HOOKPROC) &CenterMsgBoxTextProc, NULL, GetCurrentThreadId());
MessageBox(...);
if (hHook) UnhookWindowsHookEx(hHook);
Alternatively, you can use SetWinEventHook() instead of SetWindowsHookEx():
void CALLBACK CenterMsgBoxTextProc(HWINEVENTHOOK hWinEventHook, DWORD event, HWND hwnd, LONG idObject, LONG idChild, DWORD dwEventThread, DWORD dwmsEventTime)
{
HWND hTxt = FindWindowEx(hwnd, NULL, TEXT("STATIC"), NULL);
if (hTxt)
SetWindowLong(hTxt, GWL_STYLE, GetWindowLong(hTxt, GWL_STYLE) | SS_CENTER);
}
HWINEVENTHOOK hHook = SetWinEventHook(EVENT_OBJECT_CREATE, EVENT_OBJECT_CREATE, NULL, &CenterMsgBoxTextProc, GetCurrentProcessId(), GetCurrentThreadId(), 0);
MessageBox(NULL, TEXT("test"), TEXT("test"), MB_OK);
if (hHook) UnhookWinEvent(hHook);
Here is what the result looks like in both cases:
Afaik there is not. But it is actually quite easy to create such a dialog using Win32 resources and the DialogBox function.
Using Visual Studio C++ with MFC. How do I center a MessageBox to it's parent window? Currently it centers to the desktop.
You need to install a hook and change the dialog box position on creation.
int MessageBoxCentered(HWND hWnd, LPCTSTR lpText, LPCTSTR lpCaption, UINT uType)
{
// Center message box at its parent window
static HHOOK hHookCBT{};
hHookCBT = SetWindowsHookEx(WH_CBT,
[](int nCode, WPARAM wParam, LPARAM lParam) -> LRESULT
{
if (nCode == HCBT_CREATEWND)
{
if (((LPCBT_CREATEWND)lParam)->lpcs->lpszClass == (LPWSTR)(ATOM)32770) // #32770 = dialog box class
{
RECT rcParent{};
GetWindowRect(((LPCBT_CREATEWND)lParam)->lpcs->hwndParent, &rcParent);
((LPCBT_CREATEWND)lParam)->lpcs->x = rcParent.left + ((rcParent.right - rcParent.left) - ((LPCBT_CREATEWND)lParam)->lpcs->cx) / 2;
((LPCBT_CREATEWND)lParam)->lpcs->y = rcParent.top + ((rcParent.bottom - rcParent.top) - ((LPCBT_CREATEWND)lParam)->lpcs->cy) / 2;
}
}
return CallNextHookEx(hHookCBT, nCode, wParam, lParam);
},
0, GetCurrentThreadId());
int iRet{ MessageBox(hWnd, lpText, lpCaption, uType) };
UnhookWindowsHookEx(hHookCBT);
return iRet;
}
::AfxMessageBox() appears on the center of the MainFrame for me. Which is basically a call to ::MessageBox() with a handle to the MainFrame as the first parameter. Isn't that working for you?
You can't. That's why a lot of people write their own MessageBox classes.
Who said "can't"?
Try this:
This is for Win32 API, written in C. Translate it as you need...
case WM_NOTIFY:{
HWND X=FindWindow("#32770",NULL);
if(GetParent(X)==H_frame){int Px,Py,Sx,Sy; RECT R1,R2;
GetWindowRect(hwnd,&R1); GetWindowRect(X,&R2);
Sx=R2.right-R2.left,Px=R1.left+(R1.right-R1.left)/2-Sx/2;
Sy=R2.bottom-R2.top,Py=R1.top+(R1.bottom-R1.top)/2-Sy/2;
MoveWindow(X,Px,Py,Sx,Sy,1);
}
} break;
Add that to the WndProc code... You can set position as you like, in this case it just centres over the main program window. It will do this for any messagebox, or file open/save dialog, and likely some other native controls. I'm not sure, but I think you may need to include COMMCTRL or COMMDLG to use this, at least, you will if you want open/save dialogs.
I experimented with looking at the notify codes and hwndFrom of NMHDR, then decided it was just as effective, and far easier, not to. If you really want to be very specific, tell FindWindow to look for a unique caption (title) you give to the window you want it to find.
This fires before the messagebox is drawn onscreen, so if you set a global flag to indicate when action is done by your code, and look for a unique caption, you be sure that actions you take will only occur once (there will likely be multiple notifiers). I haven't explored this in detail, but I managed get CreateWindow to put an edit box on a messagebox dialog. It looked as out of place as a rat's ear grafted onto the spine of a cloned pig, but it works. Doing things this way may be far easier than having to roll your own.
Crow.
EDIT: Small correction to handle the problem raised by Raymond Chen. Make sure that parent handles agree throughout, and this should work ok. It does for me, even with two instances of the same program...