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1.1 root 1: /*************************************************************************\
2: * PROGRAM: sharemem.c
3: *
4: * PURPOSE:
5: *
6: * To demonstrate the use of named shared memory between two independent
7: * processes.
8: *
9: * GLOBAL VARIABLES:
10: *
11: * HANDLE hInst: - Instance handle.
12: *
13: * HWND hWnd: - Client window handle.
14: *
15: * HWND hWndDlg: - Handle to the dialog box which is imposed over the
16: * parent window.
17: *
18: * LONG *MapView: - Address of where the file will be mapped to.
19: *
20: * HANDLE hMapObject:
21: * - Handle to the file mapping object.
22: *
23: *
24: * FUNCTIONS:
25: *
26: * WinMain() - Initializes the window, and process the message loop.
27: * MainWndProc() - To handle the messages to the main window.
28: *
29: * COMMENTS:
30: *
31: * Overview:
32: * This sample is accompanied by the Othrproc (Other Procedure)
33: * application. Basically this code traps WM_MOUSEMOVE messages
34: * and writes them to the shared memory. The Otherproc code
35: * reads the share memory and blts a small bitmap in the same
36: * relative coordinates. The effect is to have the mouse move
37: * in one window, while the bitmap moves in the same relative
38: * position in the other window. The mouse coordinates will appear
39: * in the edit fields of the dialog box at the top of the parent
40: * windows.
41: *
42: * To Use:
43: * First start Sharemem, then start Otherproc. The visual effect
44: * is better if the focus remains with Otherproc, while the mouse
45: * moves with the Sharemem window.
46: *
47: \*************************************************************************/
48:
49: #include <windows.h>
50: #include <stdlib.h>
51: #include <stdio.h>
52: #include "sharemem.h"
53:
54: #define WERR(who,where) {sprintf(Buf,"ERROR: %s returned %u, line: %u", who, GetLastError(), __LINE__);\
55: sprintf(Buf2,"From within %s", where);\
56: MessageBox(hwnd, Buf, Buf2, MB_OK);}
57:
58: CHAR Buf[80];
59: CHAR Buf2[80];
60:
61:
62: HANDLE hInst;
63: HANDLE hMapObject;
64: HWND hWnd, hWndDlg;
65: LONG *MapView;
66:
67:
68:
69: /*************************************************************************\
70: *
71: * FUNCTION: WinMain(HANDLE, HANDLE, LPSTR, int)
72: *
73: * PURPOSE: Initializes the window, processes message loop.
74: *
75: * COMMENTS: A fairly standard WinMain except that it creates a dialog
76: * box which is imposed on the upper part of the window. This
77: * dialog box is used to show the mouse coordinates.
78: *
79: \*************************************************************************/
80:
81: int APIENTRY WinMain (HANDLE hInstance,
82: HANDLE hPrevInstance,
83: LPSTR lpCmdLine,
84: int nCmdShow)
85:
86:
87: {
88:
89: MSG msg;
90: WNDCLASS wc;
91: RECT rect;
92:
93: UNREFERENCED_PARAMETER( lpCmdLine );
94: UNREFERENCED_PARAMETER( hPrevInstance );
95:
96: hInst = hInstance;
97:
98: wc.style = NULL;
99: wc.lpfnWndProc = (WNDPROC)MainWndProc;
100: wc.cbClsExtra = 0;
101: wc.cbWndExtra = 0;
102: wc.hInstance = hInstance;
103: wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
104: wc.hCursor = LoadCursor (NULL, IDC_ARROW);
105: wc.hbrBackground = GetStockObject (WHITE_BRUSH);
106: wc.lpszMenuName = "";
107: wc.lpszClassName = "ShareMemWClass";
108:
109: RegisterClass(&wc);
110:
111: hWnd = CreateWindow ("ShareMemWClass",
112: "Shared Memory Sample",
113: WS_OVERLAPPEDWINDOW,
114: CW_USEDEFAULT,
115: CW_USEDEFAULT,
116: CW_USEDEFAULT,
117: CW_USEDEFAULT,
118: NULL,
119: NULL,
120: hInstance,
121: NULL);
122:
123: hWndDlg = CreateDialog (hInst, "StatusDlg", hWnd, NULL);
124:
125: GetClientRect (hWnd, &rect);
126: SendMessage (hWnd, WM_SIZE, 0, (rect.right - rect.left));
127: ShowWindow (hWndDlg, SW_SHOW);
128: ShowWindow (hWnd, nCmdShow);
129:
130: while (GetMessage (&msg, NULL, NULL, NULL))
131: if (!IsDialogMessage (hWndDlg, &msg))
132: {
133: DispatchMessage (&msg); // Dispatch message to window.
134: }
135:
136: return (msg.wParam); // Returns value from PostQuitMessage.
137:
138: }
139:
140: /*************************************************************************\
141: *
142: * FUNCTION: MainWndProc (HWND, UINT, UINT, LONG)
143: *
144: * PURPOSE: To process messages. To create the shared memory.
145: *
146: * MESSAGES:
147: *
148: * WM_CREATE - Create the shared memory by calling
149: * CreateFileMapping(). This memory is the size
150: * of a DWORD, all the size that is needed to pass
151: * mouse coordinates. If the CreateFileMapping()
152: * call is successful, it then calls MapViewOfFile()
153: * to get the address of the memory.
154: *
155: * WM_MOUSEMOVE - Traps the mouse move messages, and uses structured
156: * exception handling to write the mouse coordinates
157: * to the share memory. It also sends the coordinates
158: * to the edit fields of the dialog box.
159: *
160: * WM_DESTROY - Closes the memory handle, and destroys the window.
161: *
162: * WM_SIZE - Updates the size of the dialog box to maintain
163: * its relative size to the client window.
164: *
165: * CALLED BY:
166: *
167: * WinMain();
168: *
169: \*************************************************************************/
170:
171: LONG APIENTRY MainWndProc (HWND hwnd,
172: UINT message,
173: UINT wParam,
174: LONG lParam)
175: {
176:
177: switch (message)
178: {
179:
180: case WM_CREATE:
181: hMapObject = CreateFileMapping ((HANDLE) 0xFFFFFFFF,
182: NULL,
183: PAGE_READWRITE,
184: 0,
185: sizeof(DWORD),
186: "shared_memory");
187: if (!hMapObject)
188: {
189: WERR("CreateFileMapping","WM_CREATE");
190: }
191: (LPVOID)MapView = MapViewOfFile (hMapObject,
192: FILE_MAP_WRITE,
193: 0, 0, 0);
194: if (!MapView)
195: MessageBox (hwnd, "ERROR: MapViewOfFile was not successful.",
196: "From within WM_CREATE", MB_OK);
197: return (0);
198:
199:
200: case WM_SIZE :
201: SetWindowPos (hWndDlg, NULL, 0,0, LOWORD(lParam), DIALOGHEIGHT, NULL);
202: return (0);
203:
204:
205: case WM_MOUSEMOVE:
206:
207: try
208: {
209: MapView[0] = lParam;
210: }
211: except(EXCEPTION_EXECUTE_HANDLER)
212: {
213: MessageBox( hwnd, "Trapped an exception when writing to memory.",
214: "From within WM_MOUSEMOVE", MB_OK);
215: }
216:
217: SetDlgItemInt (hWndDlg, IDE_XCOORD, LOWORD(lParam), FALSE);
218: SetDlgItemInt (hWndDlg, IDE_YCOORD, HIWORD(lParam), FALSE);
219: return (0);
220:
221: case WM_DESTROY :
222: CloseHandle (hMapObject);
223: PostQuitMessage (0);
224: return (0);
225:
226: }
227: return DefWindowProc (hwnd, message, wParam, lParam);
228: }
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