![第4章，[标签 Win32] ：加入滚动条的 SysMets](images/news1.jpg)
专栏导航上一篇第4章[标签 Win32] 滚动条消息回到目录下一篇第4章[标签 Win32] SysMets2 初步讲解本节前言对于本节所讲解的知识有可能你会需要时不时地参考本专栏的其它文章。真的遇到了需要参考之前的文章的知识点请你自行查阅。我呢也会提到一部分的参考课节。但是呢你不应该依赖于我的主动提及。最好呢你自己能够多去了解和查看本专栏目录。在学习完了基础版滚动条函数的知识以后我们尝试着在之前的 SysMets1 程序的基础上加入滚动条代码构建本节的 SysMets2 。我们开始本节的学习。一. 本节代码本节我们仅仅是在原有的 SysMets1 的基础上加入垂直滚动条。至于水平滚动条我们暂且不添加。实际上仅仅是加入垂直滚动条就够你品味一会儿了。下面分别展示本节代码。一SysMets.h代码如下。/*----------------------------------------------- SYSMETS.H -- System metrics display structure -----------------------------------------------*/ #define NUMLINES ((int) (sizeof sysmetrics / sizeof sysmetrics [0])) struct { int iIndex; TCHAR* szLabel; TCHAR* szDesc; } sysmetrics[] { SM_CXSCREEN, TEXT(SM_CXSCREEN), TEXT(Screen width in pixels), SM_CYSCREEN, TEXT(SM_CYSCREEN), TEXT(Screen height in pixels), SM_CXVSCROLL, TEXT(SM_CXVSCROLL), TEXT(Vertical scroll width), SM_CYHSCROLL, TEXT(SM_CYHSCROLL), TEXT(Horizontal scroll height), SM_CYCAPTION, TEXT(SM_CYCAPTION), TEXT(Caption bar height), SM_CXBORDER, TEXT(SM_CXBORDER), TEXT(Window border width), SM_CYBORDER, TEXT(SM_CYBORDER), TEXT(Window border height), SM_CXFIXEDFRAME, TEXT(SM_CXFIXEDFRAME), TEXT(Dialog window frame width), SM_CYFIXEDFRAME, TEXT(SM_CYFIXEDFRAME), TEXT(Dialog window frame height), SM_CYVTHUMB, TEXT(SM_CYVTHUMB), TEXT(Vertical scroll thumb height), SM_CXHTHUMB, TEXT(SM_CXHTHUMB), TEXT(Horizontal scroll thumb width), SM_CXICON, TEXT(SM_CXICON), TEXT(Icon width), SM_CYICON, TEXT(SM_CYICON), TEXT(Icon height), SM_CXCURSOR, TEXT(SM_CXCURSOR), TEXT(Cursor width), SM_CYCURSOR, TEXT(SM_CYCURSOR), TEXT(Cursor height), SM_CYMENU, TEXT(SM_CYMENU), TEXT(Menu bar height), SM_CXFULLSCREEN, TEXT(SM_CXFULLSCREEN), TEXT(Full screen client area width), SM_CYFULLSCREEN, TEXT(SM_CYFULLSCREEN), TEXT(Full screen client area height), SM_CYKANJIWINDOW, TEXT(SM_CYKANJIWINDOW), TEXT(Kanji window height), SM_MOUSEPRESENT, TEXT(SM_MOUSEPRESENT), TEXT(Mouse present flag), SM_CYVSCROLL, TEXT(SM_CYVSCROLL), TEXT(Vertical scroll arrow height), SM_CXHSCROLL, TEXT(SM_CXHSCROLL), TEXT(Horizontal scroll arrow width), SM_DEBUG, TEXT(SM_DEBUG), TEXT(Debug version flag), SM_SWAPBUTTON, TEXT(SM_SWAPBUTTON), TEXT(Mouse buttons swapped flag), SM_CXMIN, TEXT(SM_CXMIN), TEXT(Minimum window width), SM_CYMIN, TEXT(SM_CYMIN), TEXT(Minimum window height), SM_CXSIZE, TEXT(SM_CXSIZE), TEXT(Min/Max/Close button width), SM_CYSIZE, TEXT(SM_CYSIZE), TEXT(Min/Max/Close button height), SM_CXSIZEFRAME, TEXT(SM_CXSIZEFRAME), TEXT(Window sizing frame width), SM_CYSIZEFRAME, TEXT(SM_CYSIZEFRAME), TEXT(Window sizing frame height), SM_CXMINTRACK, TEXT(SM_CXMINTRACK), TEXT(Minimum window tracking width), SM_CYMINTRACK, TEXT(SM_CYMINTRACK), TEXT(Minimum window tracking height), SM_CXDOUBLECLK, TEXT(SM_CXDOUBLECLK), TEXT(Double click x tolerance), SM_CYDOUBLECLK, TEXT(SM_CYDOUBLECLK), TEXT(Double click y tolerance), SM_CXICONSPACING, TEXT(SM_CXICONSPACING), TEXT(Horizontal icon spacing), SM_CYICONSPACING, TEXT(SM_CYICONSPACING), TEXT(Vertical icon spacing), SM_MENUDROPALIGNMENT, TEXT(SM_MENUDROPALIGNMENT), TEXT(Left or right menu drop), SM_PENWINDOWS, TEXT(SM_PENWINDOWS), TEXT(Pen extensions installed), SM_DBCSENABLED, TEXT(SM_DBCSENABLED), TEXT(Double-Byte Char Set enabled), SM_CMOUSEBUTTONS, TEXT(SM_CMOUSEBUTTONS), TEXT(Number of mouse buttons), SM_SECURE, TEXT(SM_SECURE), TEXT(Security present flag), SM_CXEDGE, TEXT(SM_CXEDGE), TEXT(3-D border width), SM_CYEDGE, TEXT(SM_CYEDGE), TEXT(3-D border height), SM_CXMINSPACING, TEXT(SM_CXMINSPACING), TEXT(Minimized window spacing width), SM_CYMINSPACING, TEXT(SM_CYMINSPACING), TEXT(Minimized window spacing height), SM_CXSMICON, TEXT(SM_CXSMICON), TEXT(Small icon width), SM_CYSMICON, TEXT(SM_CYSMICON), TEXT(Small icon height), SM_CYSMCAPTION, TEXT(SM_CYSMCAPTION), TEXT(Small caption height), SM_CXSMSIZE, TEXT(SM_CXSMSIZE), TEXT(Small caption button width), SM_CYSMSIZE, TEXT(SM_CYSMSIZE), TEXT(Small caption button height), SM_CXMENUSIZE, TEXT(SM_CXMENUSIZE), TEXT(Menu bar button width), SM_CYMENUSIZE, TEXT(SM_CYMENUSIZE), TEXT(Menu bar button height), SM_ARRANGE, TEXT(SM_ARRANGE), TEXT(How minimized windows arranged), SM_CXMINIMIZED, TEXT(SM_CXMINIMIZED), TEXT(Minimized window width), SM_CYMINIMIZED, TEXT(SM_CYMINIMIZED), TEXT(Minimized window height), SM_CXMAXTRACK, TEXT(SM_CXMAXTRACK), TEXT(Maximum draggable width), SM_CYMAXTRACK, TEXT(SM_CYMAXTRACK), TEXT(Maximum draggable height), SM_CXMAXIMIZED, TEXT(SM_CXMAXIMIZED), TEXT(Width of maximized window), SM_CYMAXIMIZED, TEXT(SM_CYMAXIMIZED), TEXT(Height of maximized window), SM_NETWORK, TEXT(SM_NETWORK), TEXT(Network present flag), SM_CLEANBOOT, TEXT(SM_CLEANBOOT), TEXT(How system was booted), SM_CXDRAG, TEXT(SM_CXDRAG), TEXT(Avoid drag x tolerance), SM_CYDRAG, TEXT(SM_CYDRAG), TEXT(Avoid drag y tolerance), SM_SHOWSOUNDS, TEXT(SM_SHOWSOUNDS), TEXT(Present sounds visually), SM_CXMENUCHECK, TEXT(SM_CXMENUCHECK), TEXT(Menu check-mark width), SM_CYMENUCHECK, TEXT(SM_CYMENUCHECK), TEXT(Menu check-mark height), SM_SLOWMACHINE, TEXT(SM_SLOWMACHINE), TEXT(Slow processor flag), SM_MIDEASTENABLED, TEXT(SM_MIDEASTENABLED), TEXT(Hebrew and Arabic enabled flag), SM_MOUSEWHEELPRESENT, TEXT(SM_MOUSEWHEELPRESENT), TEXT(Mouse wheel present flag), SM_XVIRTUALSCREEN, TEXT(SM_XVIRTUALSCREEN), TEXT(Virtual screen x origin), SM_YVIRTUALSCREEN, TEXT(SM_YVIRTUALSCREEN), TEXT(Virtual screen y origin), SM_CXVIRTUALSCREEN, TEXT(SM_CXVIRTUALSCREEN), TEXT(Virtual screen width), SM_CYVIRTUALSCREEN, TEXT(SM_CYVIRTUALSCREEN), TEXT(Virtual screen height), SM_CMONITORS, TEXT(SM_CMONITORS), TEXT(Number of monitors), SM_SAMEDISPLAYFORMAT, TEXT(SM_SAMEDISPLAYFORMAT), TEXT(Same color format flag) };二WinMain.cpp代码如下。/*---------------------------------------------------- SYSMETS2.C -- System Metrics Display Program No. 2 (c) Charles Petzold, 1998 水饺编程改编版代码2026 ----------------------------------------------------*/ #define WINVER 0x0500 #include windows.h #include sysmets.h LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] TEXT(SysMets2); 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(注册窗口类失败), szAppName, MB_ICONERROR); return 0; } hwnd CreateWindow(szAppName, TEXT(Get System Metrics No. 2), 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; } LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { static int cxChar, cxCaps, cyChar, cyClient, iVscrollPos; HDC hdc; int i, y; PAINTSTRUCT ps; TCHAR szBuffer[10]; TEXTMETRIC tm; switch (message) { case WM_CREATE: hdc GetDC(hwnd); GetTextMetrics(hdc, tm); cxChar tm.tmAveCharWidth; cxCaps (tm.tmPitchAndFamily 1 ? 3 : 2) * cxChar / 2; cyChar tm.tmHeight tm.tmExternalLeading; ReleaseDC(hwnd, hdc); SetScrollRange(hwnd, SB_VERT, 0, NUMLINES - 1, FALSE); SetScrollPos(hwnd, SB_VERT, iVscrollPos, TRUE); return 0; case WM_SIZE: cyClient HIWORD(lParam); return 0; case WM_VSCROLL: switch (LOWORD(wParam)) { case SB_LINEUP: iVscrollPos - 1; break; case SB_LINEDOWN: iVscrollPos 1; break; case SB_PAGEUP: iVscrollPos - cyClient / cyChar; break; case SB_PAGEDOWN: iVscrollPos cyClient / cyChar; break; case SB_THUMBPOSITION: iVscrollPos HIWORD(wParam); break; default: break; } iVscrollPos max(0, min(iVscrollPos, NUMLINES - 1)); if (iVscrollPos ! GetScrollPos(hwnd, SB_VERT)) { SetScrollPos(hwnd, SB_VERT, iVscrollPos, TRUE); InvalidateRect(hwnd, NULL, TRUE); } return 0; case WM_PAINT: hdc BeginPaint(hwnd, ps); for (i 0; i NUMLINES; i) { y cyChar * (i - iVscrollPos); TextOut(hdc, 0, y, sysmetrics[i].szLabel, lstrlen(sysmetrics[i].szLabel)); TextOut(hdc, 22 * cxCaps, y, sysmetrics[i].szDesc, lstrlen(sysmetrics[i].szDesc)); SetTextAlign(hdc, TA_RIGHT | TA_TOP); TextOut(hdc, 22 * cxCaps 40 * cxChar, y, szBuffer, wsprintf(szBuffer, TEXT(%5d), GetSystemMetrics(sysmetrics[i].iIndex))); SetTextAlign(hdc, TA_LEFT | TA_TOP); } EndPaint(hwnd, ps); return 0; case WM_DESTROY: PostQuitMessage(0); return 0; } return DefWindowProc(hwnd, message, wParam, lParam); }到了这里代码就展示完了。二. 代码编译一基本安排我们用 VS2019 来新建一个解决方案将解决方案和项目名称都命名为【SysMets2】。然后呢分别添加本篇文章第一分节中的 SysMets.h 和 WinMain.cpp 代码文件。然后呢我们接着往下讲。二项目设置本节代码项目需要根据你所使用的 Visual Studio 软件版本来决定是否可以直接编译。如果你使用的软件版本为 2010 版和 2008 版等等的低版本 Visual Studio 软件那么你并不需要进行专门的项目设置。直接去编译项目就可以获得通过。如果你使用的软件版本为 2017 版和 2019 版等等的高版本 Visual Studio 软件那么直接去编译Visual Studio 会报错。为了让项目编译通过我们还需要对此项目进行一番设置。我们需要设置【符合模式】这一项。设置原因与设置方法详见测试案例3 的分节二与分节三的讲解。测试案例3 的课节链接如下。参考课节第4章[标签 Win32] TextOut 测试案例3设置好了以后就可以编译程序了。我这里程序是编译成功了的。运行结果如下。图1在图1 里面我用红色框线标注的部分是滚动条滑块。我们可以用鼠标拖动滚动条滑块。我们将滚动条滚动条滑块滚动一点儿举例然后松开鼠标结果如下。图2我们再将滚动条滑块往下多拖拽一会儿会有出现白色行的情况截图如下。图3到了这里本节也就结束了。专栏导航上一篇第4章[标签 Win32] 滚动条消息回到目录下一篇第4章[标签 Win32] SysMets2 初步讲解
第4章，[标签 Win32] ：加入滚动条的 SysMets
专栏导航上一篇第4章[标签 Win32] 滚动条消息回到目录下一篇第4章[标签 Win32] SysMets2 初步讲解本节前言对于本节所讲解的知识有可能你会需要时不时地参考本专栏的其它文章。真的遇到了需要参考之前的文章的知识点请你自行查阅。我呢也会提到一部分的参考课节。但是呢你不应该依赖于我的主动提及。最好呢你自己能够多去了解和查看本专栏目录。在学习完了基础版滚动条函数的知识以后我们尝试着在之前的 SysMets1 程序的基础上加入滚动条代码构建本节的 SysMets2 。我们开始本节的学习。一. 本节代码本节我们仅仅是在原有的 SysMets1 的基础上加入垂直滚动条。至于水平滚动条我们暂且不添加。实际上仅仅是加入垂直滚动条就够你品味一会儿了。下面分别展示本节代码。一SysMets.h代码如下。/*----------------------------------------------- SYSMETS.H -- System metrics display structure -----------------------------------------------*/ #define NUMLINES ((int) (sizeof sysmetrics / sizeof sysmetrics [0])) struct { int iIndex; TCHAR* szLabel; TCHAR* szDesc; } sysmetrics[] { SM_CXSCREEN, TEXT(SM_CXSCREEN), TEXT(Screen width in pixels), SM_CYSCREEN, TEXT(SM_CYSCREEN), TEXT(Screen height in pixels), SM_CXVSCROLL, TEXT(SM_CXVSCROLL), TEXT(Vertical scroll width), SM_CYHSCROLL, TEXT(SM_CYHSCROLL), TEXT(Horizontal scroll height), SM_CYCAPTION, TEXT(SM_CYCAPTION), TEXT(Caption bar height), SM_CXBORDER, TEXT(SM_CXBORDER), TEXT(Window border width), SM_CYBORDER, TEXT(SM_CYBORDER), TEXT(Window border height), SM_CXFIXEDFRAME, TEXT(SM_CXFIXEDFRAME), TEXT(Dialog window frame width), SM_CYFIXEDFRAME, TEXT(SM_CYFIXEDFRAME), TEXT(Dialog window frame height), SM_CYVTHUMB, TEXT(SM_CYVTHUMB), TEXT(Vertical scroll thumb height), SM_CXHTHUMB, TEXT(SM_CXHTHUMB), TEXT(Horizontal scroll thumb width), SM_CXICON, TEXT(SM_CXICON), TEXT(Icon width), SM_CYICON, TEXT(SM_CYICON), TEXT(Icon height), SM_CXCURSOR, TEXT(SM_CXCURSOR), TEXT(Cursor width), SM_CYCURSOR, TEXT(SM_CYCURSOR), TEXT(Cursor height), SM_CYMENU, TEXT(SM_CYMENU), TEXT(Menu bar height), SM_CXFULLSCREEN, TEXT(SM_CXFULLSCREEN), TEXT(Full screen client area width), SM_CYFULLSCREEN, TEXT(SM_CYFULLSCREEN), TEXT(Full screen client area height), SM_CYKANJIWINDOW, TEXT(SM_CYKANJIWINDOW), TEXT(Kanji window height), SM_MOUSEPRESENT, TEXT(SM_MOUSEPRESENT), TEXT(Mouse present flag), SM_CYVSCROLL, TEXT(SM_CYVSCROLL), TEXT(Vertical scroll arrow height), SM_CXHSCROLL, TEXT(SM_CXHSCROLL), TEXT(Horizontal scroll arrow width), SM_DEBUG, TEXT(SM_DEBUG), TEXT(Debug version flag), SM_SWAPBUTTON, TEXT(SM_SWAPBUTTON), TEXT(Mouse buttons swapped flag), SM_CXMIN, TEXT(SM_CXMIN), TEXT(Minimum window width), SM_CYMIN, TEXT(SM_CYMIN), TEXT(Minimum window height), SM_CXSIZE, TEXT(SM_CXSIZE), TEXT(Min/Max/Close button width), SM_CYSIZE, TEXT(SM_CYSIZE), TEXT(Min/Max/Close button height), SM_CXSIZEFRAME, TEXT(SM_CXSIZEFRAME), TEXT(Window sizing frame width), SM_CYSIZEFRAME, TEXT(SM_CYSIZEFRAME), TEXT(Window sizing frame height), SM_CXMINTRACK, TEXT(SM_CXMINTRACK), TEXT(Minimum window tracking width), SM_CYMINTRACK, TEXT(SM_CYMINTRACK), TEXT(Minimum window tracking height), SM_CXDOUBLECLK, TEXT(SM_CXDOUBLECLK), TEXT(Double click x tolerance), SM_CYDOUBLECLK, TEXT(SM_CYDOUBLECLK), TEXT(Double click y tolerance), SM_CXICONSPACING, TEXT(SM_CXICONSPACING), TEXT(Horizontal icon spacing), SM_CYICONSPACING, TEXT(SM_CYICONSPACING), TEXT(Vertical icon spacing), SM_MENUDROPALIGNMENT, TEXT(SM_MENUDROPALIGNMENT), TEXT(Left or right menu drop), SM_PENWINDOWS, TEXT(SM_PENWINDOWS), TEXT(Pen extensions installed), SM_DBCSENABLED, TEXT(SM_DBCSENABLED), TEXT(Double-Byte Char Set enabled), SM_CMOUSEBUTTONS, TEXT(SM_CMOUSEBUTTONS), TEXT(Number of mouse buttons), SM_SECURE, TEXT(SM_SECURE), TEXT(Security present flag), SM_CXEDGE, TEXT(SM_CXEDGE), TEXT(3-D border width), SM_CYEDGE, TEXT(SM_CYEDGE), TEXT(3-D border height), SM_CXMINSPACING, TEXT(SM_CXMINSPACING), TEXT(Minimized window spacing width), SM_CYMINSPACING, TEXT(SM_CYMINSPACING), TEXT(Minimized window spacing height), SM_CXSMICON, TEXT(SM_CXSMICON), TEXT(Small icon width), SM_CYSMICON, TEXT(SM_CYSMICON), TEXT(Small icon height), SM_CYSMCAPTION, TEXT(SM_CYSMCAPTION), TEXT(Small caption height), SM_CXSMSIZE, TEXT(SM_CXSMSIZE), TEXT(Small caption button width), SM_CYSMSIZE, TEXT(SM_CYSMSIZE), TEXT(Small caption button height), SM_CXMENUSIZE, TEXT(SM_CXMENUSIZE), TEXT(Menu bar button width), SM_CYMENUSIZE, TEXT(SM_CYMENUSIZE), TEXT(Menu bar button height), SM_ARRANGE, TEXT(SM_ARRANGE), TEXT(How minimized windows arranged), SM_CXMINIMIZED, TEXT(SM_CXMINIMIZED), TEXT(Minimized window width), SM_CYMINIMIZED, TEXT(SM_CYMINIMIZED), TEXT(Minimized window height), SM_CXMAXTRACK, TEXT(SM_CXMAXTRACK), TEXT(Maximum draggable width), SM_CYMAXTRACK, TEXT(SM_CYMAXTRACK), TEXT(Maximum draggable height), SM_CXMAXIMIZED, TEXT(SM_CXMAXIMIZED), TEXT(Width of maximized window), SM_CYMAXIMIZED, TEXT(SM_CYMAXIMIZED), TEXT(Height of maximized window), SM_NETWORK, TEXT(SM_NETWORK), TEXT(Network present flag), SM_CLEANBOOT, TEXT(SM_CLEANBOOT), TEXT(How system was booted), SM_CXDRAG, TEXT(SM_CXDRAG), TEXT(Avoid drag x tolerance), SM_CYDRAG, TEXT(SM_CYDRAG), TEXT(Avoid drag y tolerance), SM_SHOWSOUNDS, TEXT(SM_SHOWSOUNDS), TEXT(Present sounds visually), SM_CXMENUCHECK, TEXT(SM_CXMENUCHECK), TEXT(Menu check-mark width), SM_CYMENUCHECK, TEXT(SM_CYMENUCHECK), TEXT(Menu check-mark height), SM_SLOWMACHINE, TEXT(SM_SLOWMACHINE), TEXT(Slow processor flag), SM_MIDEASTENABLED, TEXT(SM_MIDEASTENABLED), TEXT(Hebrew and Arabic enabled flag), SM_MOUSEWHEELPRESENT, TEXT(SM_MOUSEWHEELPRESENT), TEXT(Mouse wheel present flag), SM_XVIRTUALSCREEN, TEXT(SM_XVIRTUALSCREEN), TEXT(Virtual screen x origin), SM_YVIRTUALSCREEN, TEXT(SM_YVIRTUALSCREEN), TEXT(Virtual screen y origin), SM_CXVIRTUALSCREEN, TEXT(SM_CXVIRTUALSCREEN), TEXT(Virtual screen width), SM_CYVIRTUALSCREEN, TEXT(SM_CYVIRTUALSCREEN), TEXT(Virtual screen height), SM_CMONITORS, TEXT(SM_CMONITORS), TEXT(Number of monitors), SM_SAMEDISPLAYFORMAT, TEXT(SM_SAMEDISPLAYFORMAT), TEXT(Same color format flag) };二WinMain.cpp代码如下。/*---------------------------------------------------- SYSMETS2.C -- System Metrics Display Program No. 2 (c) Charles Petzold, 1998 水饺编程改编版代码2026 ----------------------------------------------------*/ #define WINVER 0x0500 #include windows.h #include sysmets.h LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] TEXT(SysMets2); 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(注册窗口类失败), szAppName, MB_ICONERROR); return 0; } hwnd CreateWindow(szAppName, TEXT(Get System Metrics No. 2), 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; } LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { static int cxChar, cxCaps, cyChar, cyClient, iVscrollPos; HDC hdc; int i, y; PAINTSTRUCT ps; TCHAR szBuffer[10]; TEXTMETRIC tm; switch (message) { case WM_CREATE: hdc GetDC(hwnd); GetTextMetrics(hdc, tm); cxChar tm.tmAveCharWidth; cxCaps (tm.tmPitchAndFamily 1 ? 3 : 2) * cxChar / 2; cyChar tm.tmHeight tm.tmExternalLeading; ReleaseDC(hwnd, hdc); SetScrollRange(hwnd, SB_VERT, 0, NUMLINES - 1, FALSE); SetScrollPos(hwnd, SB_VERT, iVscrollPos, TRUE); return 0; case WM_SIZE: cyClient HIWORD(lParam); return 0; case WM_VSCROLL: switch (LOWORD(wParam)) { case SB_LINEUP: iVscrollPos - 1; break; case SB_LINEDOWN: iVscrollPos 1; break; case SB_PAGEUP: iVscrollPos - cyClient / cyChar; break; case SB_PAGEDOWN: iVscrollPos cyClient / cyChar; break; case SB_THUMBPOSITION: iVscrollPos HIWORD(wParam); break; default: break; } iVscrollPos max(0, min(iVscrollPos, NUMLINES - 1)); if (iVscrollPos ! GetScrollPos(hwnd, SB_VERT)) { SetScrollPos(hwnd, SB_VERT, iVscrollPos, TRUE); InvalidateRect(hwnd, NULL, TRUE); } return 0; case WM_PAINT: hdc BeginPaint(hwnd, ps); for (i 0; i NUMLINES; i) { y cyChar * (i - iVscrollPos); TextOut(hdc, 0, y, sysmetrics[i].szLabel, lstrlen(sysmetrics[i].szLabel)); TextOut(hdc, 22 * cxCaps, y, sysmetrics[i].szDesc, lstrlen(sysmetrics[i].szDesc)); SetTextAlign(hdc, TA_RIGHT | TA_TOP); TextOut(hdc, 22 * cxCaps 40 * cxChar, y, szBuffer, wsprintf(szBuffer, TEXT(%5d), GetSystemMetrics(sysmetrics[i].iIndex))); SetTextAlign(hdc, TA_LEFT | TA_TOP); } EndPaint(hwnd, ps); return 0; case WM_DESTROY: PostQuitMessage(0); return 0; } return DefWindowProc(hwnd, message, wParam, lParam); }到了这里代码就展示完了。二. 代码编译一基本安排我们用 VS2019 来新建一个解决方案将解决方案和项目名称都命名为【SysMets2】。然后呢分别添加本篇文章第一分节中的 SysMets.h 和 WinMain.cpp 代码文件。然后呢我们接着往下讲。二项目设置本节代码项目需要根据你所使用的 Visual Studio 软件版本来决定是否可以直接编译。如果你使用的软件版本为 2010 版和 2008 版等等的低版本 Visual Studio 软件那么你并不需要进行专门的项目设置。直接去编译项目就可以获得通过。如果你使用的软件版本为 2017 版和 2019 版等等的高版本 Visual Studio 软件那么直接去编译Visual Studio 会报错。为了让项目编译通过我们还需要对此项目进行一番设置。我们需要设置【符合模式】这一项。设置原因与设置方法详见测试案例3 的分节二与分节三的讲解。测试案例3 的课节链接如下。参考课节第4章[标签 Win32] TextOut 测试案例3设置好了以后就可以编译程序了。我这里程序是编译成功了的。运行结果如下。图1在图1 里面我用红色框线标注的部分是滚动条滑块。我们可以用鼠标拖动滚动条滑块。我们将滚动条滚动条滑块滚动一点儿举例然后松开鼠标结果如下。图2我们再将滚动条滑块往下多拖拽一会儿会有出现白色行的情况截图如下。图3到了这里本节也就结束了。专栏导航上一篇第4章[标签 Win32] 滚动条消息回到目录下一篇第4章[标签 Win32] SysMets2 初步讲解
