第六章 键盘part2

6.3字符消息

四类字符消息:

非系统字符WM_CHAR和WM_DEADCHAR消息是从WM_KEYDOWN得到的；而系统字符WM_SYSCHAR和WM_SYSDEADCHAR消息是从WM_SYSKEYDOWN消息得到的。在大多数情况下，Windows程序会忽略除WM_CHAR之外的任何消息。伴随四个字符消息的lParam参数与产生字符代码消息的按键消息之lParam参数相同。如果您的窗口消息处理程序需要晓得目前窗口是否处理Unicode消息，则它可以呼叫：fUnicode = IsWindowUnicode(hwnd);

消息顺序:

TranslateMessage函数从WM_KEYDOWN和WM_SYSKEYDOWN消息产生了字符消息，所以字符消息是夹在按键消息之间传递给窗口消息处理程序的。

1.按下A键的消息顺序：WM_KEYDOWN -- WM_CHAR --WM_KEYUP

2.按下Shift键，再按下A键，然后释放A键，再释放Shift键：WM_KEYDOWN -- WM_KEYDOWN -- WM_CHAR -- WM_KEYUP -- WM_KEYUP (Shift键本身不产生字符消息)

3.自动重复按住A键:WM_KEYDOWN -- WM_CHAR -- WM_KEYDOWN -- WM_CHAR -- WM_KEYDOWN -- WM_CHAR  -- WM_KEYUP

处理控制字符:

如果需要读取输入到窗口的键盘字符，那么可以处理WM_CHAR消息。如果需要读取光标键、功能键、Delete、Insert、Shift、Ctrl以及Alt键，那么您可以处理WM_KEYDOWN消息。Tab、Enter、Backspace和Escape键处理成控制字符而不是虚拟键。

死字符消息：

Windows程序经常忽略WM_DEADCHAR和WM_SYSDEADCHAR消息

在某些非U.S.英语键盘上，有些键用于给字母加上音调。因为它们本身不产生字符，所以称之为「死键」。当使用者按下这个死键时，窗口消息处理程序接收到一个wParam等于音调本身的ASCII或者Unicode代码的WM_DEADCHAR消息。

 

6.4键盘消息和字符集

KeyView1:

#include <windows.h> LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT ("KeyView1") ; HWND hwnd ; MSG msg ; WNDCLASS wndclass ; wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; wndclass.cbClsExtra = 0 ; wndclass.cbWndExtra = 0 ; wndclass.hInstance = hInstance ; wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ; wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ; wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ; wndclass.lpszMenuName = NULL ; wndclass.lpszClassName = szAppName ; if (!RegisterClass (&wndclass)) { MessageBox (NULL, TEXT ("This program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow (szAppName, TEXT ("Keyboard Message Viewer #1"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ; while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ; } /************************************************************************//*KEYVIEW1显示窗口消息处理程序接收到的每次按键和字符消息的内容，并将这些消息储存在一个MSG结构的数组中*//************************************************************************/LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { static int cxClientMax, cyClientMax, cxClient, cyClient, cxChar, cyChar ; static int cLinesMax, cLines ; static PMSG pmsg ; static RECT rectScroll ;//标题文字static TCHAR szTop[] = TEXT ("Message Key Char ") TEXT ("Repeat Scan Ext ALT Prev Tran") ; //底线static TCHAR szUnd[] = TEXT ("_______ ___ ____ ") TEXT ("______ ____ ___ ___ ____ ____") ; static TCHAR * szFormat[2] = { TEXT ("%-13s %3d %-15s%c%6u %4d %3s %3s %4s %4s"), TEXT ("%-13s 0x%04X%1s%c %6u %4d %3s %3s %4s %4s") } ; static TCHAR * szYes = TEXT ("Yes") ; static TCHAR * szNo = TEXT ("No") ; static TCHAR * szDown = TEXT ("Down") ; static TCHAR * szUp = TEXT ("Up") ; static TCHAR * szMessage [] = { TEXT ("WM_KEYDOWN"), TEXT ("WM_KEYUP"),TEXT ("WM_CHAR"), TEXT ("WM_DEADCHAR"), TEXT ("WM_SYSKEYDOWN"),TEXT ("WM_SYSKEYUP"), TEXT ("WM_SYSCHAR"), TEXT ("WM_SYSDEADCHAR") } ; HDC hdc ; int i, iType ; PAINTSTRUCT ps ; TCHAR szBuffer[128], szKeyName [32] ; TEXTMETRIC tm ; switch (message) { case WM_CREATE: case WM_DISPLAYCHANGE: // Get maximum size of client area cxClientMax = GetSystemMetrics(SM_CXMAXIMIZED); cyClientMax = GetSystemMetrics(SM_CYMAXIMIZED); // Get character size for fixed-pitch font hdc = GetDC(hwnd); SelectObject(hdc, GetStockObject(SYSTEM_FIXED_FONT)); GetTextMetrics(hdc, &tm); cxChar = tm.tmAveCharWidth; cyChar = tm.tmHeight; ReleaseDC(hwnd, hdc); // Allocate memory for display lines if (pmsg) free(pmsg);//最大的行数cLinesMax = cyClientMax / cyChar;//申请出每行的内存pmsg = (PMSG)malloc(cLinesMax * sizeof(MSG)); cLines = 0 ; // fall through case WM_SIZE: if (message == WM_SIZE) { cxClient = LOWORD (lParam) ; cyClient = HIWORD (lParam) ; } // Calculate scrolling rectangle rectScroll.left = 0 ; rectScroll.right = cxClient ; rectScroll.top = cyChar ; rectScroll.bottom = cyChar * (cyClient / cyChar) ; //窗体添加一个矩形，然后窗口客户区域的这一部分将被重新绘制InvalidateRect(hwnd, NULL, TRUE); return 0 ; case WM_KEYDOWN: case WM_KEYUP: case WM_CHAR: case WM_DEADCHAR: case WM_SYSKEYDOWN: case WM_SYSKEYUP: case WM_SYSCHAR: case WM_SYSDEADCHAR: //把最新的消息放到第一个位置// Rearrange storage array for (i = cLinesMax - 1 ; i > 0 ; i--) { pmsg[i] = pmsg[i - 1] ; } // Store new message pmsg[0].hwnd = hwnd ; pmsg[0].message = message ; pmsg[0].wParam = wParam ; pmsg[0].lParam = lParam ; cLines = min(cLines + 1, cLinesMax); //该函数滚动所指定的窗口客户区域内容。//函数提供了向后兼容性，新的应用程序应使用ScrollWindowEXScrollWindow(hwnd, 0, -cyChar, &rectScroll, &rectScroll) ; break ;// i.e., call DefWindowProc so Sys messag work case WM_PAINT: hdc = BeginPaint(hwnd, &ps); SelectObject (hdc, GetStockObject(SYSTEM_FIXED_FONT)) ;//设置透明背景SetBkMode(hdc, TRANSPARENT) ;//画标题文字和底线TextOut (hdc, 0, 0, szTop, lstrlen (szTop)) ; TextOut (hdc, 0, 0, szUnd, lstrlen (szUnd)) ; //循环行数for (i = 0 ; i < min (cLines, cyClient / cyChar - 1) ; i++) { iType = pmsg[i].message == WM_CHAR || pmsg[i].message == WM_SYSCHAR || pmsg[i].message == WM_DEADCHAR || pmsg[i].message == WM_SYSDEADCHAR ; //显示了按键消息的虚拟键代码GetKeyNameText(pmsg[i].lParam, szKeyName, sizeof (szKeyName) / sizeof (TCHAR)) ; TextOut(hdc, 0, (cyClient / cyChar - 1 - i) * cyChar, szBuffer, wsprintf (szBuffer, szFormat [iType], szMessage [pmsg[i].message - WM_KEYFIRST], pmsg[i].wParam, (PTSTR) (iType ? TEXT (" ") : szKeyName), (TCHAR) (iType ? pmsg[i].wParam : ' '), LOWORD (pmsg[i].lParam), HIWORD (pmsg[i].lParam) & 0xFF, 0x01000000 & pmsg[i].lParam ? szYes : szNo, 0x20000000 & pmsg[i].lParam ? szYes : szNo, 0x40000000 & pmsg[i].lParam ? szDown : szUp, 0x80000000 & pmsg[i].lParam ? szUp : szDown)) ; } EndPaint(hwnd, &ps) ; return 0 ; case WM_DESTROY:PostQuitMessage(0); return 0 ; } return DefWindowProc(hwnd, message, wParam, lParam) ; }

字符集和字体
用于在屏幕上显示字符的字体和键盘接收的字符代码不一致。Windows支持三类字体－点阵字体、向量字体和（从Windows 3.1开始的）TrueType字体。在内定的设备内容下获得的点阵字体称为系统字体。您可通过呼叫带有SYSTEM_FONT标识符的GetStockObject函数来获得字体句柄。

StokFont:

#include <windows.h> LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT ("StokFont") ; HWND hwnd ; MSG msg ; WNDCLASS wndclass ; wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; wndclass.cbClsExtra = 0 ; wndclass.cbWndExtra = 0 ; wndclass.hInstance = hInstance ; wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ; wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ; wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH); wndclass.lpszMenuName = NULL ; wndclass.lpszClassName = szAppName ; if (!RegisterClass (&wndclass)) { MessageBox ( NULL, TEXT ("Program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow ( szAppName, TEXT ("Stock Fonts"), WS_OVERLAPPEDWINDOW | WS_VSCROLL, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ; while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ; } typedef struct _StockFont { int idStockFont;const char* szStockFont; }StockFont; LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wParam,LPARAM lParam) { static StockFont stockfont[] = { OEM_FIXED_FONT, "OEM_FIXED_FONT", ANSI_FIXED_FONT, "ANSI_FIXED_FONT", ANSI_VAR_FONT, "ANSI_VAR_FONT", SYSTEM_FONT, "SYSTEM_FONT", DEVICE_DEFAULT_FONT, "DEVICE_DEFAULT_FONT", SYSTEM_FIXED_FONT, "SYSTEM_FIXED_FONT", DEFAULT_GUI_FONT, "DEFAULT_GUI_FONT"}; static int iFont, cFonts = sizeof stockfont / sizeof stockfont[0] ; HDC hdc ; int i, x, y, cxGrid, cyGrid ; PAINTSTRUCT ps ; TCHAR szFaceName[LF_FACESIZE], szBuffer[LF_FACESIZE + 64] ; TEXTMETRIC tm ;switch (message) { case WM_CREATE: SetScrollRange(hwnd, SB_VERT, 0, cFonts - 1, TRUE); return 0 ; //当显示分辨率发生改变时,该消息发送给所有的窗口case WM_DISPLAYCHANGE: InvalidateRect(hwnd, NULL, TRUE); return 0 ; case WM_VSCROLL: switch (LOWORD(wParam)) { case SB_TOP: iFont = 0; break; case SB_BOTTOM: iFont = cFonts - 1; break; case SB_LINEUP: case SB_PAGEUP: iFont -= 1;break ; case SB_LINEDOWN: case SB_PAGEDOWN:iFont += 1; break ; case SB_THUMBPOSITION:iFont = HIWORD(wParam);break ; } //一共有七个iFont = max(0, min (cFonts - 1, iFont)) ;// 该函数设置所指定滚动条中的滚动按钮的位置，// 如果需要，可重绘滚动条以反映出滚动按钮的新位置SetScrollPos(hwnd, SB_VERT, iFont, TRUE) ; InvalidateRect(hwnd, NULL, TRUE) ; return 0 ; case WM_KEYDOWN: switch (wParam) {case VK_HOME: SendMessage(hwnd, WM_VSCROLL, SB_TOP, 0); break ; case VK_END: SendMessage(hwnd, WM_VSCROLL, SB_BOTTOM, 0);break ; case VK_PRIOR: case VK_LEFT: case VK_UP: SendMessage(hwnd, WM_VSCROLL, SB_LINEUP, 0); break ; case VK_NEXT: case VK_RIGHT: case VK_DOWN: SendMessage(hwnd, WM_VSCROLL, SB_PAGEDOWN, 0); break; } return 0; case WM_PAINT: hdc = BeginPaint(hwnd, &ps) ; SelectObject(hdc, GetStockObject(stockfont[iFont].idStockFont));//得到的字体样式名称GetTextFace(hdc, LF_FACESIZE, szFaceName); GetTextMetrics(hdc, &tm); cxGrid = max (3 * tm.tmAveCharWidth, 2 * tm.tmMaxCharWidth); cyGrid = tm.tmHeight + 3; TextOut (hdc, 0, 0, szBuffer, wsprintf (szBuffer, TEXT (" %s: Face Name = %s, CharSet = %i"), stockfont[iFont].szStockFont, szFaceName, tm.tmCharSet)); SetTextAlign (hdc, TA_TOP | TA_CENTER); // vertical and horizontal lines for (i = 0 ; i < 17 ; i++) { MoveToEx (hdc, (i + 2) * cxGrid, 2 * cyGrid, NULL); LineTo(hdc, (i + 2) * cxGrid, 19 * cyGrid); MoveToEx(hdc, cxGrid, (i + 3) * cyGrid, NULL); LineTo(hdc, 18 * cxGrid, (i + 3) * cyGrid); } // vertical and horizontal headings for (i = 0 ; i < 16 ; i++) { TextOut (hdc, (2 * i + 5) * cxGrid / 2, 2 * cyGrid + 2, szBuffer, wsprintf (szBuffer, TEXT ("%X-"), i)) ; TextOut (hdc, 3 * cxGrid / 2, (i + 3) * cyGrid + 2, szBuffer, wsprintf (szBuffer, TEXT ("-%X"), i)) ; } //输出字符for (y = 0 ; y < 16 ; y++) for (x = 0 ; x < 16 ; x++) { TextOut (hdc, (2 * x + 5) * cxGrid / 2, (y + 3) * cyGrid + 2, szBuffer, wsprintf (szBuffer, TEXT ("%c"), 16 * x + y)) ; } EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY: PostQuitMessage(0); return 0 ; } return DefWindowProc(hwnd, message, wParam, lParam) ; }

TrueType和大字体：
点阵字体（在日文版Windows中带有附加字体）最多包括256个字符。

 

 

6.5插入符号（不是光标）

插入符号函数:

CreateCaret  建立与窗口有关的插入符号
SetCaretPos  在窗口中设定插入符号的位置
ShowCaret  显示插入符号
HideCaret  隐藏插入符号
DestroyCaret  撤消插入符号

另外还有取得插入符号目前位置（GetCaretPos）和取得以及设定插入符号闪烁时间（GetCaretBlinkTime和SetCaretBlinkTime）的函数。

一个消息队列只能支持一个插入符号。因此，如果您的程序有多个窗口，那么各个窗口必须有效地共享相同的插入符号。

通过处理WM_SETFOCUS和WM_KILLFOCUS消息，程序就可以确定它是否有输入焦点。

使用插入符号的主要规则很简单： 窗口消息处理程序在WM_SETFOCUS消息处理期间呼叫CreateCaret，在WM_KILLFOCUS消息处理期间呼叫DestroyCaret。
插入符号刚建立时是隐蔽的。如果想使插入符号可见，那么您在呼叫CreateCaret之后，窗口消息处理程序还必须呼叫ShowCaret。

TYPER程序:

#include <windows.h> #define BUFFER(x,y) *(pBuffer + y * cxBuffer + x) LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT ("Typer") ; HWND hwnd ; MSG msg ; WNDCLASS wndclass ; wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; wndclass.cbClsExtra = 0 ; wndclass.cbWndExtra = 0 ; wndclass.hInstance = hInstance ; wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ; wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ; wndclass.hbrBackground = (HBRUSH) GetStockObject(WHITE_BRUSH) ; wndclass.lpszMenuName = NULL ; wndclass.lpszClassName = szAppName ;if (!RegisterClass (&wndclass)) { MessageBox ( NULL, TEXT ("This program requires Windows NT!"), szAppName, MB_ICONERROR) ; return 0 ; } hwnd = CreateWindow (szAppName, TEXT ("Typing Program"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ; while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ; }LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,LPARAM lParam) { static DWORD dwCharSet = DEFAULT_CHARSET ;//xCaret和yCaret变量保存插入符号位置。static int cxChar, cyChar, cxClient, cyClient, cxBuffer, cyBuffer, xCaret, yCaret ; static TCHAR *pBuffer = NULL ; HDC hdc ; int x, y, i ; PAINTSTRUCT ps ; TEXTMETRIC tm ; switch (message) { case WM_INPUTLANGCHANGE: dwCharSet = wParam ; // fall through case WM_CREATE: hdc = GetDC (hwnd) ; SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0,dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; GetTextMetrics(hdc, &tm); cxChar = tm.tmAveCharWidth ; cyChar = tm.tmHeight ; //通过GetStockObject和SelectObject呼叫来选择等宽字体DeleteObject(SelectObject(hdc, GetStockObject (SYSTEM_FONT))); ReleaseDC(hwnd, hdc); // fall through case WM_SIZE: // obtain window size in pixels if (message == WM_SIZE) { cxClient = LOWORD (lParam) ; cyClient = HIWORD (lParam) ; } // calculate window size in characters cxBuffer = max (1, cxClient / cxChar) ; cyBuffer = max (1, cyClient / cyChar) ; // allocate memory for buffer and clear it if (pBuffer != NULL)free(pBuffer); pBuffer = (TCHAR *)malloc(cxBuffer * cyBuffer * sizeof (TCHAR)) ; for (y = 0 ; y < cyBuffer ; y++) for (x = 0 ; x < cxBuffer ; x++) BUFFER(x,y) = ' ' ; // set caret to upper left corner xCaret = 0 ; yCaret = 0 ; //GetFocus 确定当前焦点位于哪个控件上if (hwnd == GetFocus ()) SetCaretPos(xCaret * cxChar, yCaret * cyChar) ; InvalidateRect (hwnd, NULL, TRUE) ; return 0 ; case WM_SETFOCUS: //该函数为系统插入标记创建一个新的形状，//并且将插入标记的属主关系指定给特定的窗口。插入标记的形状。可以是线、块或位图//在这里是呼叫CreateCaret来建立与字符有相同宽度和高度的插入符号CreateCaret (hwnd, NULL, cxChar, cyChar) ;//该函数将插入标记移动到指定的坐标上。SetCaretPos (xCaret * cxChar, yCaret * cyChar) ;//该函数使插入标记在屏幕的当前位置上可见。//当插入标记变为可见时，它自动开始闪烁。ShowCaret (hwnd) ; return 0 ; case WM_KILLFOCUS: //该函数将屏幕上的插入标记清除。//实际上是隐藏插入标记，并不是删除其当前形状或使插入点无效。 HideCaret (hwnd) ;//该函数清除插入标记的当前形状，从窗口中释放插入标记，并且删除屏幕上的插入标记。//如果插入标记的形状是基于位图的，那么DestroyCaret不释放该位图DestroyCaret () ; return 0 ; case WM_KEYDOWN: switch (wParam) { case VK_HOME: xCaret = 0 ; break ; case VK_END: xCaret = cxBuffer - 1 ; break ; case VK_PRIOR: yCaret = 0 ; break ; case VK_NEXT: yCaret = cyBuffer - 1 ; break ; case VK_LEFT: xCaret = max (xCaret - 1, 0) ; break ; case VK_RIGHT: xCaret = min (xCaret + 1, cxBuffer - 1) ; break ; case VK_UP: yCaret = max (yCaret - 1, 0) ; break ; case VK_DOWN: yCaret = min (yCaret + 1, cyBuffer - 1) ; break ; case VK_DELETE: for (x = xCaret ; x < cxBuffer - 1 ; x++) BUFFER (x, yCaret) = BUFFER (x + 1, yCaret) ; BUFFER (cxBuffer - 1, yCaret) = ' ' ; HideCaret (hwnd) ; hdc = GetDC (hwnd) ; SelectObject (hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0,FIXED_PITCH, NULL)) ; TextOut (hdc, xCaret * cxChar, yCaret * cyChar, & BUFFER (xCaret, yCaret), cxBuffer - xCaret) ; DeleteObject(SelectObject(hdc, GetStockObject(SYSTEM_FONT))) ; ReleaseDC (hwnd, hdc) ; ShowCaret (hwnd) ; break ; }//在窗口中设定插入符号的位置SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; return 0 ;case WM_CHAR://WM_CHAR处理Backspace、Tab、Linefeed（Ctrl-Enter） 、Enter、Escape和字符键。for (i = 0 ; i < (int) LOWORD (lParam) ; i++) { switch (wParam) { case '/b':// backspace if (xCaret > 0) { xCaret-- ; SendMessage(hwnd, WM_KEYDOWN, VK_DELETE, 1) ; } break; case '/t': // tab do{ SendMessage(hwnd, WM_CHAR, ' ', 1) ; } while (xCaret % 8 != 0) ; break; case '/n': // line feed if (++yCaret == cyBuffer) yCaret = 0 ; break ; case '/r':// carriage return xCaret = 0 ; if (++yCaret == cyBuffer) yCaret = 0 ; break ; case '/x1B'://escape for (y = 0 ; y < cyBuffer ; y++) for (x = 0 ; x < cxBuffer ; x++) BUFFER (x, y) = ' '; xCaret = 0 ; yCaret = 0 ; InvalidateRect(hwnd, NULL, FALSE) ; break ; default://character codes BUFFER (xCaret, yCaret) = (TCHAR) wParam ; HideCaret(hwnd) ; hdc = GetDC(hwnd) ; //该函数创建一种有特殊性的逻辑字体，此逻辑字体可以在后面被任何设备选择SelectObject(hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; TextOut (hdc, xCaret * cxChar, yCaret * cyChar, & BUFFER (xCaret, yCaret), 1) ; DeleteObject (SelectObject(hdc, GetStockObject(SYSTEM_FONT))) ; ReleaseDC(hwnd, hdc);//显示插入符号ShowCaret(hwnd) ; if (++xCaret == cxBuffer) { xCaret = 0 ; if (++yCaret == cyBuffer) yCaret = 0 ; } break ; } } SetCaretPos (xCaret * cxChar, yCaret * cyChar) ; return 0 ; case WM_PAINT: hdc = BeginPaint(hwnd, &ps) ; SelectObject(hdc, CreateFont (0, 0, 0, 0, 0, 0, 0, 0, dwCharSet, 0, 0, 0, FIXED_PITCH, NULL)) ; for (y = 0 ; y < cyBuffer ; y++) TextOut (hdc, 0, y * cyChar, & BUFFER(0,y), cxBuffer) ; DeleteObject (SelectObject (hdc, GetStockObject (SYSTEM_FONT))) ; EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY: PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ; }