Thread: Using Arrow Keys in Windows

First let me tell you what I'm trying to accomplish. I am making a windows app where the user hits the up arrow key and somthing happens...obviously I am starting to lean towards a windows game. Anyway, here is my WM_MOVE message, I think this is where my action is:

Code:

case WM_MOVE:
         {
         // extract the position
         int xpos = LOWORD(lparam);
         int ypos = HIWORD(lparam);

         // get a graphics context
         hdc = GetDC(hwnd);

         // set the foreground color to green
         SetTextColor(hdc, RGB(0,255,0));
         
         // set the background color to black
         SetBkColor(hdc, RGB(0,0,0));
         
         // set the transparency mode to OPAQUE
         SetBkMode(hdc, OPAQUE);

         // get the up arrow key from the user
         char key=getch();
		 if(key == VK_UP){
         TextOut(hdc, 0,0, "Hi", strlen("Hi"));
		 }
         // release the dc back
         ReleaseDC(hwnd, hdc);

         } break;

if I get rid of 'if key == VK_UP' stuff then the Textout thing works. But with it, I press the up arrow key and it doesn't work. Could someone please tell me why? thanks.

look for the WM_KEYDOWN message

like so...

case WM_KEYDOWN:
// the key pressed is stored in wParam
// do something or set a flag for the key(i recommend the flag and doing the actions elsewhere)

case WM_KEYUP:
// the key pressed is stored in wParam
// reset the flag, or finish what your doing...

You might also try DirectInput for keyboard handling -- it allows you to capture keystrokes bypassing windows messaging entirely. It would allow you to directly read the state of any key, with less hassle.

you can also put this a the top of you program

#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1)

and then have statements like this
if (KEY_DOWN(VK_SPACE))
in your main event loop