case WM_CREATE:
{
int randomsize=0;
//std::string lineofquote;
char lineofquote[255];
std::ifstream infile;
infile.open("quotes.txt",std::ios::in);
if (infile)
{
MessageBox(NULL,"infile failed","Error reading file", MB_OK);
return 0;
}
newhandler = CreateWindow(TEXT("static"),TEXT("Quote here") ,WS_CHILD | WS_VISIBLE , 0,0,550,150,hWnd,NULL,NULL,NULL);
while(!infile.eof())//get file size
{
infile.getline(lineofquote,255,'\n');
SetWindowText(newhandler,lineofquote);
randomsize++;
}
infile.close();
//std::cout<<randomsize;
break;
}
When i run this program, i dont seem to see my windows at all. What might be the problem here?
That is not the way you create a window. You create a window using CreateWindow API. There are a couple of things you need to do along with it. May be this MSDN tutorial can help.
WM_CREATE is an event fired when a window is created, typically using the above API.
Always read the documentation properly. As long as you are dealing with Win32 APIs, MSDN will be your bible.
Check your ShowWindow() function. You could set CmdShow parameter to 0 which means that your window will not be visible, or just simply you forgot to call this function. Also, you could check if RegisterClassEx(...) worked propely.
Related
I'm working on an application for taking screenshots on Windows, OSX and Linux in C++/Qt. Now I need to set global hotkeys, so the user can take screenshots when the application is running in the background. I tried with Qxt and UGlobalHotkey, which are both Qt libraries, but neither of them seemed to work.
I tried to implement it for OSX with Carbon (tutorial), but I need to call a class member function, which just doesn't work. Could someone provide me with an example? You can find my code here. The function i need to call is new_screenshot().
Or is there any other way to achieve something like this? I really need my application to take a screenshot from the background, otherwise it's pretty useless (yes, I should probably have implemented it at the very beginning to see if it even works). Would it maybe be better to have a separate client for every platform (Cocoa Swift for OSX, GTK for Linux, C# client for Windows)? I have often thought about this the past few days.
Do I understand correctly that you want to call new_screenshot from the hot key event handler? If so, InstallApplicationEventHandler lets you pass a pointer to user data in 4th argument. Pass a pointer to your MainWindow instance (based on code from the tutorial):
MainWindow *mainWindow = ... // get main window somehow
InstallApplicationEventHandler(&MyHotKeyHandler,1,&eventType,mainWindow,NULL);
Then you can use it in the event handler.
OSStatus MyHotKeyHandler(EventHandlerCallRef nextHandler,EventRef theEvent, void *userData)
{
//Do something once the key is pressed
static_cast<MainWindow*>(userData)->new_screenshot();
return noErr;
}
I did something in the past with MFC and WIN32 API....so it only works on Windows...but pressing ALT+F10 was able to hide/show a window...
void CWinHideDlg::OnButtonActive()
{
CString tmp;
GetDlgItemText(IDC_BUTTON_ACTIVE,tmp);
if(0 == strcmp(tmp.GetBuffer(tmp.GetLength()),"Activate"))
{
m_myAtom=GlobalAddAtom("MY_GLOBAL_HOT_HIDE_KEY");
int err=RegisterHotKey(this->GetSafeHwnd(),m_myAtom,MOD_ALT,VK_F10);
SetDlgItemText(IDC_BUTTON_ACTIVE,"Stop");
CButton *pBtn = (CButton *)GetDlgItem(IDC_BUTTON_UNHIDE);
pBtn->EnableWindow(TRUE);
SetDlgItemText(IDC_STATIC_INFO,"Set the mouse over the window \nand press ALT + F10 to hide it...");
}
else
{
UnregisterHotKey(this->GetSafeHwnd(),m_myAtom);
GlobalDeleteAtom(m_myAtom);
CButton *pBtn = (CButton *)GetDlgItem(IDC_BUTTON_UNHIDE);
pBtn->EnableWindow(FALSE);
SetDlgItemText(IDC_BUTTON_ACTIVE,"Activate");
}
}
Basically this code activates/deactivates the hot key ALT+F10, once it activates you can hide/unhide a running window on the system by setting the mouse pointer over the window and press ALT+F10...
This is from the WindowProc function:
if(message == WM_HOTKEY)
{
CString tmp;
POINT pc;
GetCursorPos(&pc);
if(GetAsyncKeyState(VK_F10))
{
HWND hwnd=::WindowFromPoint(pc);
if(hwnd)
{
tmp.Format("%08Xh",hwnd);
m_HideWins.InsertString(m_HideWins.GetCount(),tmp);
::ShowWindow(hwnd,SW_HIDE);
}
}
}
You can use the code to register your own HOT Key and use it to take a screenshot...
Hope it helps...
I have been stuck here for 4 days. I made a function that puts a program in the system tray but the problem here is that it wont show balloon title and message. What Am I doing Wrong? I even made a separate function to determine what windows os we are running on and initialize cbSize based on the Os detected. Any help will be appreciated. Bellow is the function.
EDIT: I am using Windows 7 and the Icon shows up in the system tray but wont show the message or title. I am also doing this Console Application right now as this will be used as a plugin in Unity3D. I want a solution that uses windows api but not windows form as I don't want any new window to open from this.
void createSystemTray()
{
HWND wHandler = GetDesktopWindow();
NOTIFYICONDATA iData;
ZeroMemory(&iData,sizeof(iData));
if(getOsVersion()=="Windows Vista" || getOsVersion()=="Windows 7" || getOsVersion()=="Windows 8" || getOsVersion()=="Windows 8.1")
{
iData.cbSize = sizeof(NOTIFYICONDATA);
}
else if (getOsVersion()=="Windows XP"||getOsVersion()=="Windows XP Professional x64 Edition")
{
iData.cbSize = NOTIFYICONDATA_V3_SIZE;
}
else if (getOsVersion()=="Windows 2000")
{
iData.cbSize = NOTIFYICONDATA_V2_SIZE;
}
else if (getOsVersion()=="UNKNOWN OS")
{
//Assume we have old Windows Os such as Me,95....
iData.cbSize = NOTIFYICONDATA_V1_SIZE;
}
iData.hWnd = wHandler;
iData.uID = 100;
iData.uVersion = NOTIFYICON_VERSION_4;
iData.uCallbackMessage = WM_MESSAGE;
iData.hIcon = LoadIcon(NULL,(LPCTSTR)IDI_WARNING);
lstrcpy(iData.szTip,"My First Tray Icon");
lstrcpy(iData.szInfo,"My App Info");
lstrcpy(iData.szInfoTitle,"My Info Title");
iData.uFlags = NIF_MESSAGE|NIF_ICON|NIF_TIP;
Shell_NotifyIcon(NIM_SETVERSION,&iData); //called only when usingNIM_ADD
Shell_NotifyIcon(NIM_ADD,&iData);
}
I added NIF_INFO to the uFlags and the problem is gone. Now it displays everything including text, title and info title.
The code below is what solved it.
iData.uFlags = NIF_MESSAGE|NIF_ICON|NIF_TIP|NIF_SHOWTIP|NIF_INFO;
Your biggest problem with the code in the question is that you pass the wrong window handle. You have to pass one of your window handles. But instead you pass the window handle of the desktop.
You will need to create a window and use its handle. The window does not need to be visible. I believe that you can use a message only window.
You must also call NIM_SETVERSION after NIM_ADD.
I'm very sceptical of your version switching being based on string equality testing. Your code will break on Windows 9 for instance. Use the version helper functions.
You also perform no error checking. This isn't the easiest function to call but your failure to check for errors makes things even harder than they need to be. Please read the documentation and add error checking code.
I want to send keystrokes to multiple processes. For example, if I press “1”, then I want to send the “1” to 3 "Notepad windows". Frist I want to try to send a keystroke to notepad, but it fails on the HWND:
//HANDLE hWin;
HWND windowHandle = FindWindowA(NULL, "Notepad"); //Can’t find a proccess
//Send a key
if( windowHandle ) //This one fails
{
while(true)
{
if( GetAsyncKeyState(VK_F12) != 0 )
{
SendMessageA(windowHandle, WM_KEYDOWN, VK_NUMPAD1, 0);
Sleep(1000);
SendMessageA(windowHandle, WM_KEYUP, VK_NUMPAD1, 0);
}
Sleep(100);
}
}
But the "FindWindow" method is not good enough for my program. There is also no way to get 3 different processes with the same name. So how can I make 3 handles to 3 different processes with the same name? And how can I send key’s to the processes?
You can use EnumWindows for enumerating all the top level windows on the system. You then need to filter through these windows to get the ones you are interested in. Class name is probably a better choice for filtering rather than the window name though. Here is some example code (not tested) of what I have in mind:
BOOL CALLBACK BroadcastToNotepad(HWND hwnd, LPARAM lParam)
{
wchar_t lpClassName[16];
/*
* More reliable to filter by class name. We could additionally filter
* by caption name too if necessary.
*/
if(GetClassName(hwnd, lpClassName, _countof(lpClassName))) {
if(wcscmp(lpClassName, L"Notepad") == 0) {
SendMessage(hwnd, WM_KEYDOWN, (WPARAM)lParam, 0);
Sleep(1000);
SendMessage(hwnd, WM_KEYUP, (WPARAM)lParam, 0);
}
}
return TRUE;
}
// Some handler which gets invoked when your hotkey is hit.
void handlerKey1(...)
{
EnumWindows(BroadcastToNotepad, (lParam)VK_NUMPAD1)
}
Note the usage of BroadcastToNotepad and how you can have different handlers pass in a different lParam.
One final thing to note is that PostMessage/SendMessage is not a reliable way to simulate keyboard input. This is noted by Raymond Chen here. SendInput is the preferred way for injecting input. However, to use that you will need to ensure the window you want to send to has the keyboard focus.
I recall vaguely having played with something similar to what you are doing in the past. If I remember correctly, you need to send to Notepad's child window (class name = Edit). So the code above needs to be modified as so:
if(wcscmp(lpClassName, L"Notepad") == 0) {
HWND hwndChild = FindWindowEx(hwnd, NULL, L"Edit", NULL);
SendMessage(hwndChild, WM_KEYDOWN, (WPARAM)lParam, 0);
Sleep(1000);
SendMessage(hwndChild, WM_KEYUP, (WPARAM)lParam, 0);
}
Firstly install Spy++ from Visual Studio which lets you see all the HWND windows in hierarchy ( and which process owns them).
Then you'll see why your FindWindow is failing. You'll also know the exact hierarchy calls to make on FindWindow and GetWindow().
Be aware that since Vista some HWNDs are protected and you cant send to them - but notepad is probably fine.
For sending the key, you can probably just use PostMessage to fire and forget.
First of all, why is while(true) there? Wouldn't you rather want to activate your software on F12 key press than having an infinite loop? That handle is not valid forever, you know.
Second, you'd probably want to use EnumWindows to go through all the windows and find the one you're interested in. Then you'd implement a callback function that'll need to decide on some basis if it wants to act on some window or not (be it name or something else).
SendMessage/SendMessageA/SendMessageW should work just fine when you've found a proper handle for the window you want to target for (save for some special windows that are protected from this).
I am working on writing a simple game engine and I am having trouble handling Windows console events; specifically, I cannot figure out how to pass custom data to the callback handler.
I first call this code to specify my callback function:
SetConsoleCtrlHandler((PHANDLER_ROUTINE)WindowsSystemManager::ConsoleControlHandler, true);
My static-member callback function is defined as:
bool WINAPI WindowsSystemManager::ConsoleControlHandler(DWORD controlType){
if(controlType == CTRL_CLOSE_EVENT){
MessageBox(NULL, L"Close Event Captured", L"Close Event Captured", NULL);
}
return true;
}
Everything works fine - when I click on the close button in the console, this MessageBox pops up. Only problem is, I need to call code that flushes a logging buffer to a log file on this type of shutdown (as well as other clean-up), and the Logger instance is a member in my WindowsSystemManager.
I have dealt with a similar problem of passing custom data to window handles by using SetWindowLongPtr and GetWindowLongPtr successfully, but I can't find any information on how to do this type of thing with console control handlers. Any thoughts?
EDIT: I got this functionality working based on MSalters' suggestions. The final code for the console control handler is here:
bool WINAPI WindowsSystemManager::ConsoleControlHandler(DWORD controlType){
BerserkEngine* engine = (BerserkEngine*)GetWindowLongPtr(GetConsoleWindow(), GWLP_USERDATA);
if(controlType == CTRL_CLOSE_EVENT){
engine->~BerserkEngine();
PostQuitMessage(0);
}
return true;
}
Where I set this custom data pointer in the WindowsSystemManager constructor:
SetWindowLongPtr(GetConsoleWindow(), GWL_USERDATA, (LONG_PTR)this->engine);
I'm not sure why you'd need this. You can have multiple windows, but only one console.
However, GetConsoleWindow will give you the console HWND, on which you might call SetWindowLongPtr. Not very clean (you're not supposed to do this on windows that you don't manage), but it might just work.
How can I get a window visible before processing?
I'm trying to do something like this:
void CMyClass::OnButton1Clicked()
{
CString class_str = AfxRegisterWndClass(CS_VREDRAW | CS_HREDRAW, ::LoadCursor(NULL,IDC_ARROW),(HBRUSH)::GetStockObject(WHITE_BRUSH),::LoadIcon(NULL, IDI_APPLICATION));
CWnd* wnd = new CWnd();
wnd->Create(class_str,"Test",WS_CHILD | WS_VISIBLE | WS_BORDER, CRect(0,0,100,100), AfxGetMainWnd(), 1432);
//AfxMessageBox("test"); // <- if this is executed wnd gets visible before sleep()
Sleep(5000); //this would be processing
wnd->DestroyWindow();
delete wnd;
return;
}
The window doesn't show at all. I've tried displaying it in an UI thread but it doesn't show either. If I do a message loop until window is created, it shows up but after a while the main message loop asserts.
I know it shouldn't be made like this but rather processing in worker thread, but with current code I'm working with it would require changes too big.
Disclaimer: I don't know MFC, but I know the windows API, which is what MFC was built on top of.
Perhaps you need to make a call to ShowWindow(). Also, are you handling the WM_CREATE message? If so, perhaps you are returning the wrong value.
If the above doesn't apply or make sense, disregard.