WM_SYSDEADCHAR 消息问题

付笑

代码如下:

1. /*--------------------------------------------------------
   
2. KEYVIEW1.C -- Displays Keyboard and Character Messages
   
3. (c) Charles Petzold, 1998
   
4. --------------------------------------------------------*/
   
5. 
   
6. #include <windows.h>
   
7. 
   
8. LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
   
9. 
   
10. int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
    
11. PSTR szCmdLine, int iCmdShow)
    
12. {
    
13. static TCHAR szAppName[] = TEXT ("KeyView1") ;
    
14. HWND hwnd ;
    
15. MSG msg ;
    
16. WNDCLASS wndclass ;
    
17. 
    
18. wndclass.style = CS_HREDRAW | CS_VREDRAW ;
    
19. wndclass.lpfnWndProc = WndProc ;
    
20. wndclass.cbClsExtra = 0 ;
    
21. wndclass.cbWndExtra = 0 ;
    
22. wndclass.hInstance = hInstance ;
    
23. wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
    
24. wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;
    
25. wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
    
26. wndclass.lpszMenuName = NULL ;
    
27. wndclass.lpszClassName = szAppName ;
    
28. 
    
29. if (!RegisterClass (&wndclass))
    
30. {
    
31. MessageBox (NULL, TEXT ("This program requires Windows NT!"),
    
32. szAppName, MB_ICONERROR) ;
    
33. return 0 ;
    
34. }
    
35. 
    
36. hwnd = CreateWindow (szAppName, TEXT ("Keyboard Message Viewer #1"),
    
37. WS_OVERLAPPEDWINDOW,
    
38. CW_USEDEFAULT, CW_USEDEFAULT,
    
39. CW_USEDEFAULT, CW_USEDEFAULT,
    
40. NULL, NULL, hInstance, NULL) ;
    
41. 
    
42. ShowWindow (hwnd, iCmdShow) ;
    
43. UpdateWindow (hwnd) ;
    
44. 
    
45. while (GetMessage (&msg, NULL, 0, 0))
    
46. {
    
47. TranslateMessage (&msg) ;
    
48. DispatchMessage (&msg) ;
    
49. }
    
50. return msg.wParam ;
    
51. }
    
52. 
    
53. LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
    
54. {
    
55. static int cxClientMax, cyClientMax, cxClient, cyClient, cxChar, cyChar ;
    
56. static int cLinesMax, cLines ;
    
57. static PMSG pmsg ;
    
58. static RECT rectScroll ;
    
59. static TCHAR szTop[] = TEXT ("Message Key Char ")
    
60. TEXT ("Repeat Scan Ext ALT Prev Tran") ;
    
61. static TCHAR szUnd[] = TEXT ("_______ ___ ____ ")
    
62. TEXT ("______ ____ ___ ___ ____ ____") ;
    
63. 
    
64. static TCHAR * szFormat[2] = {
    
65. 
    
66. TEXT ("%-13s %3d %-15s%c%6u %4d %3s %3s %4s %4s"),
    
67. TEXT ("%-13s 0x%04X%1s%c %6u %4d %3s %3s %4s %4s") } ;
    
68. 
    
69. static TCHAR * szYes = TEXT ("Yes") ;
    
70. static TCHAR * szNo = TEXT ("No") ;
    
71. static TCHAR * szDown = TEXT ("Down") ;
    
72. static TCHAR * szUp = TEXT ("Up") ;
    
73. 
    
74. static TCHAR * szMessage [] = {
    
75. TEXT ("WM_KEYDOWN"), TEXT ("WM_KEYUP"),
    
76. TEXT ("WM_CHAR"), TEXT ("WM_DEADCHAR"),
    
77. TEXT ("WM_SYSKEYDOWN"), TEXT ("WM_SYSKEYUP"),
    
78. TEXT ("WM_SYSCHAR"), TEXT ("WM_SYSDEADCHAR") } ;
    
79. HDC hdc ;
    
80. int i, iType ;
    
81. PAINTSTRUCT ps ;
    
82. TCHAR szBuffer[128], szKeyName [32] ;
    
83. TEXTMETRIC tm ;
    
84. 
    
85. switch (message)
    
86. {
    
87. case WM_CREATE:
    
88. case WM_DISPLAYCHANGE:
    
89. 
    
90. // Get maximum size of client area
    
91. 
    
92. cxClientMax = GetSystemMetrics (SM_CXMAXIMIZED) ;
    
93. cyClientMax = GetSystemMetrics (SM_CYMAXIMIZED) ;
    
94. 
    
95. // Get character size for fixed-pitch font
    
96. 
    
97. hdc = GetDC (hwnd) ;
    
98. 
    
99. SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
    
100. GetTextMetrics (hdc, &tm) ;
     
101. cxChar = tm.tmAveCharWidth ;
     
102. cyChar = tm.tmHeight ;
     
103. 
     
104. ReleaseDC (hwnd, hdc) ;
     
105. 
     
106. // Allocate memory for display lines
     
107. 
     
108. if (pmsg)
     
109. free (pmsg) ;
     
110. 
     
111. cLinesMax = cyClientMax / cyChar ;
     
112. pmsg = malloc (cLinesMax * sizeof (MSG)) ;
     
113. cLines = 0 ;
     
114. // fall through
     
115. case WM_SIZE:
     
116. if (message == WM_SIZE)
     
117. {
     
118. cxClient = LOWORD (lParam) ;
     
119. cyClient = HIWORD (lParam) ;
     
120. }
     
121. // Calculate scrolling rectangle
     
122. 
     
123. rectScroll.left = 0 ;
     
124. rectScroll.right = cxClient ;
     
125. rectScroll.top = cyChar ;
     
126. rectScroll.bottom = cyChar * (cyClient / cyChar) ;
     
127. 
     
128. InvalidateRect (hwnd, NULL, TRUE) ;
     
129. return 0 ;
     
130. 
     
131. case WM_KEYDOWN:
     
132. case WM_KEYUP:
     
133. case WM_CHAR:
     
134. case WM_DEADCHAR:
     
135. case WM_SYSKEYDOWN:
     
136. case WM_SYSKEYUP:
     
137. case WM_SYSCHAR:
     
138. case WM_SYSDEADCHAR:
     
139. 
     
140. // Rearrange storage array
     
141. 
     
142. for (i = cLinesMax - 1 ; i > 0 ; i--)
     
143. {
     
144. pmsg[i] = pmsg[i - 1] ;
     
145. }
     
146. // Store new message
     
147. 
     
148. pmsg[0].hwnd = hwnd ;
     
149. pmsg[0].message = message ;
     
150. pmsg[0].wParam = wParam ;
     
151. pmsg[0].lParam = lParam ;
     
152. 
     
153. cLines = min (cLines + 1, cLinesMax) ;
     
154. 
     
155. // Scroll up the display
     
156. 
     
157. ScrollWindow (hwnd, 0, -cyChar, &rectScroll, &rectScroll) ;
     
158. 
     
159. break ; // ie, call DefWindowProc so Sys messages work
     
160. 
     
161. case WM_PAINT:
     
162. hdc = BeginPaint (hwnd, &ps) ;
     
163. 
     
164. SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
     
165. SetBkMode (hdc, TRANSPARENT) ;
     
166. TextOut (hdc, 0, 0, szTop, lstrlen (szTop)) ;
     
167. 
     
168. TextOut (hdc, 0, 0, szUnd, lstrlen (szUnd)) ;
     
169. 
     
170. for (i = 0 ; i < min (cLines, cyClient / cyChar - 1) ; i++)
     
171. {
     
172. iType = pmsg[i].message == WM_CHAR ||
     
173. pmsg[i].message == WM_SYSCHAR ||
     
174. pmsg[i].message == WM_DEADCHAR ||
     
175. pmsg[i].message == WM_SYSDEADCHAR ;
     
176. 
     
177. GetKeyNameText (pmsg[i].lParam, szKeyName,
     
178. sizeof (szKeyName) / sizeof (TCHAR)) ;
     
179. 
     
180. TextOut (hdc, 0, (cyClient / cyChar - 1 - i) * cyChar, szBuffer,
     
181. wsprintf (szBuffer, szFormat [iType],
     
182. szMessage [pmsg[i].message - WM_KEYFIRST],
     
183. pmsg[i].wParam,
     
184. (PTSTR) (iType ? TEXT (" ") : szKeyName),
     
185. (TCHAR) (iType ? pmsg[i].wParam : ' '),
     
186. LOWORD (pmsg[i].lParam),
     
187. HIWORD (pmsg[i].lParam) & 0xFF,
     
188. 0x01000000 & pmsg[i].lParam ? szYes : szNo,
     
189. 0x20000000 & pmsg[i].lParam ? szYes : szNo,
     
190. 0x40000000 & pmsg[i].lParam ? szDown : szUp,
     
191. 0x80000000 & pmsg[i].lParam ? szUp : szDown)) ;
     
192. }
     
193. EndPaint (hwnd, &ps) ;
     
194. return 0 ;
     
195. 
     
196. case WM_DESTROY:
     
197. PostQuitMessage (0) ;
     
198. return 0 ;
     
199. }
     
200. return DefWindowProc (hwnd, message, wParam, lParam) ;
     
201. }
     

复制代码

调试这个程序的时候发现，只要按下任意一个键 窗口过程就会收到  WM_SYSDEADCHAR消息
这个消息不是要按Alt+某键 才会产生吗，为什么随便按一个键就会有  WM_SYSDEADCHAR 这个消息呢
求解答

如梦幻泡影

WM_SYSDEADCHAR
The WM_SYSDEADCHAR message is sent to the window with the keyboard focus when a WM_SYSKEYDOWN message is translated by the TranslateMessage function. WM_SYSDEADCHAR specifies the character code of a system dead key — that is, a dead key that is pressed while holding down the alt key.

感觉跟参数有关系的,感觉而已啊==!
29 Specifies the context code. The value is 1 if the ALT key is down while the key is pressed; it is 0 if the WM_SYSKEYDOWN message is posted to the active window because no window has the keyboard focus.
//谷歌翻译:29指定上下文代码。该值是1 ，如果Alt键不放，同时按下键，否则，该值为0

判断是否有按下alt,还可以用GetKeyState这个来判断