I have some question about WM_COMMAND.
Is it possible if I change variable x in the case branch for WM_COMMAND to get this new value in the case branch for WM_LBUTTONDOWN?
I always get 0 in the WM_LBUTTONDOWN branch and 1 in the WM_COMMAND branch.
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int x = 0;
switch (message)
{
case WM_CREATE:
break;
case WM_COMMAND:
x = 1;
cout << x;
break;
case WM_LBUTTONDOWN:
cout << x;
break;
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
x is a local variable that you initialize to 0 every time WindowProcedure is called.
Declare x outside of WindowProcedure, or make it static.
Related
Is there a way to automatically/by default set the mouse cursor to point inside a newly created window (using for e.g. the CreateWindow function)? I know that for keyboard input there is a SetFocus() function, but haven't found a similar function for a mouse.
As #IInspectable said, the following is the code implementation.
LRESULT CALLBACK WndProcNOP(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_CREATE:
{
RECT rcClient;
GetWindowRect(hwnd, &rcClient);
int x = rcClient.left + (rcClient.right - rcClient.left) / 2;
int y = rcClient.top + (rcClient.bottom - rcClient.top) / 2;
SetCursorPos(x, y);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProcW(hwnd, msg, wParam, lParam);
}
return 0;
}
The focus event on the combo box is generated twice.
this is the code for the Action Procedure of the Dialog box.
INT_PTR DialogBox::ActionProc(
HWND hwndDlg,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
switch (LOWORD(wParam))
{
case COMBOBOX:
{
if (CBN_SETFOCUS == HIWORD(wParam))
{
MessageBox(
hwndDlg,
CString("Test"),
CString("Test"),
(MB_ICONEXCLAMATION | MB_OK));
}
break;
}
default:
break;
}
break;
}
default:
break;
}
return INT_PTR(true);
}
the MessageBox Gets displayed twice(because the focus event is generated twice on the combo box). Is there a way to display it only once.
I have tried focussing to another element such as:
INT_PTR DialogBox::ActionProc(
HWND hwndDlg,
UINT message,
WPARAM wParam,
LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
switch (LOWORD(wParam))
{
case COMBOBOX:
{
if (CBN_SETFOCUS == HIWORD(wParam))
{
MessageBox(
hwndDlg,
CString("Test"),
CString("Test"),
(MB_ICONEXCLAMATION | MB_OK));
SendDlgItemMessage(
hwndDlg,
ANOTHER_CONTROL,
WM_SETFOCUS,
0,
0);
}
break;
}
default:
break;
}
break;
}
default:
break;
}
return INT_PTR(true);
}
Can some one tell me what i am doing wrong.
This is in Windows Desktop API.
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{ HDC hdc;
int count=1; int xs,ys,xe,ye;
switch (message)
{
case WM_LBUTTONDOWN
hdc=GetDC(hwnd);
if(count%2!=1){
xs=GET_X_LPARAM(lParam);
ys=GET_Y_LPARAM(lParam);}
else{
xe=GET_X_LPARAM(lParam);
ye=GET_Y_LPARAM(lParam);
drawline(hdc,xs,ys,xe,ye);
}
ReleaseDC(hwnd,hdc);
count++;
break;
case WM_DESTROY:
PostQuitMessage (0);
break;
default:
return DefWindowProc (hwnd, message, wParam, lParam);
}
I've tried , but there's something wrong with this code.
Use
if(count%2 == 1)
insted of
if(count%2 != 1)
Might work then.
Currently, I am creating my own function onPress and onRelease. However, I am having problem with my onRelease function. Apparently, my onRelease kept on triggering even if I have not release my keyboard.
I suspected it has to do with the number of cycle inside the CPU but I wasn't sure of this theory. Somehow, maybe the cycle is slower than my frame, that why the PeerMessage return false? As no event was triggered.
Solution to it:
**Under the WinProc function create a new case called WM_KEYUP. This event will trigger once the user leave the button. It help to solve the number of cycle inside the CPU issued.
**
*Note:
I have update my detail of my code.
Description. Window Programming
I have two std::array that store my keyboard data
1) InputCurr
2) InputPrev
std::array<char, 256> inputPrev;
std::array<char, 256> inputCurr;
While(TRUE) {
std::copy(InputCurr.begin(), InputCurr.end(), InputPrev.begin());
inputCurr.fill(0);
while(PeekMessage (&uMsg, NULL, 0, 0, PM_REMOVE))
{
TranslateMessage (&uMsg);
DispatchMessage (&uMsg);
}
if(onReleased(x030)) //Button 0
//do something
}
char onReleased(char key)
{
return (inputCurr[key] && !inputPrev[key])? 1 : 0;
}
void VEInputMessage(WPARAM key)
{
inputCurr[key]= 1; //Set to true of the keyboard key
}
LRESULT CALLBACK WinProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
HDC dc; /* device context */
PAINTSTRUCT ps; /* the paint struct */
RECT rect;
UNREFERENCED_PARAMETER(rect);
switch (msg)
{
/* when the window is created */
case WM_CREATE:
break;
/* when the rectangle is drawn */
case WM_LBUTTONDOWN:
break;
case WM_MOUSEMOVE:
break;
case WM_PAINT:
dc = BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
break;
/* When it's time for the window to be closed and removed */
case WM_DESTROY:
PostQuitMessage(0);
break;
case WM_KEYDOWN:
VEINPUT::VEInputMessage(wParam); //Updated the input key
if(wParam == AEVK_ESCAPE)
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, msg, wParam, lParam);
}
return 0;
}
I've created a custom message type for use in resizing my Window, called WM_NEED_RESIZE. I've defined it in my .h file, and initialized in my .cpp file. I have also registered my WindowProc function to accept messages. Here is the code for these items:
const uint32 WindowsGLWindow::WM_NEED_RESIZE = WM_USER + 100;
LONG WINAPI WindowsGLWindow::WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
static PAINTSTRUCT ps;// do I need this?
static sint32 newWidth = 0;
static sint32 newHeight = 0;
bool res = false;
switch (uMsg) {
case WM_PAINT:
//display();
BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
return 0;
case WM_SIZE:
//glViewport(0, 0, LOWORD(lParam), HIWORD(lParam));
res = PostMessage(hWnd, WindowsGLWindow::WM_NEED_RESIZE, wParam, lParam);
std::cout << "WM_SIZE: " << res << std::endl;
return 0;
case WindowsGLWindow::WM_NEED_RESIZE:
std::cout << "WindowsGLWindow::WM_NEED_RESIZE" << std::endl;
break;
case WM_CHAR:
switch (wParam) {
case 27: /* ESC key */
PostQuitMessage(0);
break;
}
return 0;
case WM_CLOSE:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hWnd, uMsg, wParam, lParam);
}
In another function I am running through PeekMessage(..) to collect all messages. Here is the snippet of the message pump:
MSG msg;
while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE) == TRUE) // maybe use GetInputState(?) as well?
{
if (msg.message == WM_QUIT)
retVal = -1;
if (msg.message == WindowsGLWindow::WM_NEED_RESIZE) {
uint32 newWidth = LOWORD(msg.lParam);
uint32 newHeight = HIWORD(msg.lParam);
std::cout << "PeekMessage: WindowsGLWindow::WM_NEED_RESIZE" << std::endl;
// call resize only if our window-size changed
if ((newWidth != width_) || (newHeight != height_)) {
resize(newWidth, newHeight);
}
PostMessage(msg.hwnd, WM_PAINT, 0, 0);
}
switch (msg.message) {
case WM_MOUSEMOVE:
// Retrieve mouse screen position
//int x = (short) LOWORD(lParam);
//int y = (short) HIWORD(lParam);
// Check to see if the left button is held down:
//bool leftButtonDown = wParam & MK_LBUTTON;
// Check if right button down:
//bool rightButtonDown = wParam & MK_RBUTTON;
break;
case WM_LBUTTONDOWN:
case WM_RBUTTONDOWN:
case WM_LBUTTONUP:
case WM_RBUTTONUP:
case WM_KEYUP:
case WM_KEYDOWN:
/*
switch (msg.wParam) {
case 'W':
// w key pressed
break;
case VK_RIGHT:
// Right arrow pressed
break;
default:
break;
}
*/
break;
}
TranslateMessage(&msg);
DispatchMessage(&msg);
}
My problem is that the WM_NEED_RESIZE message is only found once in the message queue when the window first opens, after which it is never found in the message queue by my PeekMessage(..). I'm really not sure why this is happening. It is, however, being received by the WindowProc(..) method (which doesn't really help me). I would appreciate any help you guys could provide.
Thanks
Jarrett
Dont use std::cout expecting to see that output in your debugger, insted use OutputDebugString(); .
You need to pass your class pointer to the last parameter of your call to CreateWindowEx, then retrieve that pointer from the LPCREATESTRUCT passed to you in the LPARAM of WM_CREATE, your class pointer will be in the lpCreateParmas feild of the struct. Set your clas pointer to the GWLP_USERDATA of your window, and on any other message calls , call GetWindowsLong , retrieve your class pointer, then pass the message, wparam, and lparam all off to your internal class message handler.
http://msdn.microsoft.com/en-us/library/ff381400%28v=VS.85%29.aspx
The message pump loop that you are showing will exit as soon as the queue is empty. I can't tell from what you've posted if it ever gets entered again.
If this is your main message pump, you should use GetMessage() instead, as it will wait until something is available before returning. Take a look at this MSDN article for more info.