C/c++一些 学习笔记

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产生GUID 字符串
void getGuid (char guid[],int length)

{
GUID gid;
::CorCreateGuid(&gid);
_snprintf(guid,length,"%08x-%04x-%04x-%-2x%02x-%02x%02x%02x%02x%02x%02x",gid.Data1,gid.Data2,gid.Data3-----------gid.Data4[0]-------gid.Data4[7];


}
---------------------------------------------------------

VC常见20中错误
1、fatal error C1010: unexpected end of file while looking for precompiled header directive。
寻找预编译头文件路径时遇到了不该遇到的文件尾。(一般是没有#include "stdafx.h")

2、fatal error C1083: Cannot open include file: 'R…….h': No such file or directory
不能打开包含文件“R…….h”：没有这样的文件或目录。

3、error C2011: 'C……': 'class' type redefinition
类“C……”重定义。

4、error C2018: unknown character '0xa3'
不认识的字符'0xa3'。(一般是汉字或中文标点符号)

5、error C2057: expected constant expression
希望是常量表达式。(一般出现在switch语句的case分支中)

6、error C2065: 'IDD_MYDIALOG' : undeclared identifier
“IDD_MYDIALOG”：未声明过的标识符。

7、error C2082: redefinition of formal parameter 'bReset'
函数参数“bReset”在函数体中重定义。

8、error C2143: syntax error: missing ':' before '{'
句法错误：“{”前缺少“;”。

9、error C2146: syntax error : missing ';' before identifier 'dc'
句法错误：在“dc”前丢了“;”。

10、error C2196: case value '69' already used
值69已经用过。(一般出现在switch语句的case分支中)

11、error C2509: 'OnTimer' : member function not declared in 'CHelloView'
成员函数“OnTimer”没有在“CHelloView”中声明。

12、error C2511: 'reset': overloaded member function 'void (int)' not found in 'B'
重载的函数“void reset(int)”在类“B”中找不到。

13、error C2555: 'B::f1': overriding virtual function differs from 'A::f1' only by return type or calling convention
类B对类A中同名函数f1的重载仅根据返回值或调用约定上的区别。

14、error C2660: 'SetTimer' : function does not take 2 parameters
“SetTimer”函数不传递2个参数。

15、warning C4035: 'f……': no return value
“f……”的return语句没有返回值。

16、warning C4553: '= =' : operator has no effect; did you intend '='?
没有效果的运算符“= =”;是否改为“=”?

17、warning C4700: local variable 'bReset' used without having been initialized
局部变量“bReset”没有初始化就使用。

18、error C4716: 'CMyApp::InitInstance' : must return a value
“CMyApp::InitInstance”函数必须返回一个值。

19、LINK : fatal error LNK1168: cannot open Debug/P1.exe for writing
连接错误：不能打开P1.exe文件，以改写内容。(一般是P1.Exe还在运行，未关闭)

20、error LNK2001: unresolved external symbol "public: virtual _ _thiscall C……::~C……(void)"
连接时发现没有实现的外部符号(变量、函数等)。

function call missing argument list 调用函数的时候没有给参数。

member function definition looks like a ctor, but name does not match enclosing class 成员函数声明了但没有使用

unexpected end of file while looking for precompiled header directive 在寻找预编译头文件时文件意外结束，编译不正常终止可能造成这种情况。

     VC++编程技术连载－－－VC++常用的函数
2007-06-08 08:46:19
                   VC++编程技术连载－－－VC++常用的函数

一、打开CD-ROM
mciSendString("Set cdAudio door open wait",NULL,0,NULL);

二、关闭CD_ROM
mciSendString("Set cdAudio door closed wait",NULL,0,NULL);

三、关闭计算机
OSVERSIONINFO OsVersionInfo; //包含操作系统版本信息的数据结构
OsVersionInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
GetVersionEx(&OsVersionInfo); //获取操作系统版本信息
if(OsVersionInfo.dwPlatformId == VER_PLATFORM_WIN32_Windows)
{
    //Windows98,调用ExitWindowsEx()函数重新启动计算机
    DWORD dwReserved;
    ExitWindowsEx(EWX_REBOOT,dwReserved); //可以改变第一个参数，实现注销用户、
    //关机、关闭电源等操作
    // 退出前的一些处理程序
}

四、重启计算机
typedef int (CALLBACK *SHUTDOWNDLG)(int); //显示关机对话框函数的指针
HINSTANCE hInst = LoadLibrary("shell32.dll"); //装入shell32.dll
SHUTDOWNDLG ShutDownDialog; //指向shell32.dll库中显示关机对话框函数的指针
if(hInst != NULL)
{
    //获得函数的地址并调用之
    ShutDownDialog = (SHUTDOWNDLG)GetProcAddress(hInst,(LPSTR)60);
   
    (*ShutDownDialog)(0);
}

五、枚举所有字体
LOGFONT lf;
lf.lfCharSet = DEFAULT_CHARSET; // Initialize the LOGFONT structure
strcpy(lf.lfFaceName,"");
CClientDC dc (this);
// Enumerate the font families
::EnumFontFamiliesEx((HDC) dc,&lf, (FONTENUMPROC) EnumFontFamProc,(LPARAM) this,0);
//枚举函数
int CALLBACK EnumFontFamProc(LPENUMLOGFONT lpelf,
                             LPNEWTEXTMETRIC lpntm,DWORD nFontType,long lparam)
                 
{
    // Create a pointer to the dialog window
    CDay7Dlg* pWnd = (CDay7Dlg*) lparam;
    // add the font name to the list box
    pWnd ->m_ctlFontList.AddString(lpelf ->elfLogFont.lfFaceName);
    // Return 1 to continue font enumeration
    return 1;
}
//其中m_ctlFontList是一个列表控件变量

六、一次只运行一个程序实例，如果已运行则退出
if( FindWindow(NULL,"程序标题")) exit(0);

七、得到当前鼠标所在位置
CPoint pt;
GetCursorPos(&pt); //得到位置

八、上下文菜单事件触发事件
OnContextMenu事件

九、显示和隐藏程序菜单
CWnd *pWnd=AfxGetMainWnd();
if(b_m) //隐藏菜单
{
    pWnd->SetMenu(NULL);
    pWnd->DrawMenuBar();
    b_m=false;
}
else
{
    CMenu menu;
    menu.LoadMenu(IDR_MAINFRAME); ////显示菜单 也可改变菜单项
    pWnd->SetMenu(&menu);
    pWnd->DrawMenuBar();
    b_m=true;
    menu.Detach();
}

十、获取可执行文件的图标
HICON hIcon=::ExtractIcon(AfxGetInstanceHandle(),_T("NotePad.exe"),0);
if (hIcon &&hIcon!=(HICON)-1)
{
    pDC->DrawIcon(10,10,hIcon);
   
}
DestroyIcon(hIcon);

十一、窗口自动靠边程序演示
BOOL AdjustPos(CRect* lpRect)
{//自动靠边
    int iSX=GetSyste                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   mMetrics(SM_CXFULLSCREEN);
    int iSY=GetSystemMetrics(SM_CYFULLSCREEN);
    RECT rWorkArea;
    BOOL bResult = SystemParametersInfo(SPI_GETWORKAREA, sizeof(RECT), &rWorkAre
        a, 0);
    CRect rcWA;
    if(!bResult)
    {//如果调用不成功就利用GetSystemMetrics获取屏幕面积
        rcWA=CRect(0,0,iSX,iSY);
    }
    else
        rcWA=rWorkArea;
    int iX=lpRect->left;
    int iY=lpRect->top;
   
    if(iX < rcWA.left + DETASTEP && iX!=rcWA.left)
    {//调整左
        //pWnd->SetWindowPos(NULL,rcWA.left,iY,0,0,SWP_NOSIZE);
        lpRect->OffsetRect(rcWA.left-iX,0);
        AdjustPos(lpRect);
        return TRUE;
    }
    if(iY < rcWA.top + DETASTEP && iY!=rcWA.top)
    {//调整上
        //pWnd->SetWindowPos(NULL ,iX,rcWA.top,0,0,SWP_NOSIZE);
        lpRect->OffsetRect(0,rcWA.top-iY);
        AdjustPos(lpRect);
        return TRUE;
    }
    if(iX + lpRect->Width() > rcWA.right - DETASTEP && iX !=rcWA.right-lpRect->Width())
    {//调整右
        //pWnd->SetWindowPos(NULL ,rcWA.right-rcW.Width(),iY,0,0,SWP_NOSIZE);
        lpRect->OffsetRect(rcWA.right-lpRect->right,0);
        AdjustPos(lpRect);
        return TRUE;
    }
    if(iY + lpRect->Height() > rcWA.bottom - DETASTEP && iY !=rcWA.bottom-lpRect
        ->Height())
    {//调整下
        //pWnd->SetWindowPos(NULL ,iX,rcWA.bottom-rcW.Height(),0,0,SWP_NOSIZE);
        lpRect->OffsetRect(0,rcWA.bottom-lpRect->bottom);
        return TRUE;
    }
    return FALSE;
}
//然后在ONMOVEING事件中使用所下过程调用
CRect r=*pRect;
AdjustPos(&r);
*pRect=(RECT)r;

十二、给系统菜单添加一个菜单项
　　给系统菜单添加一个菜单项需要进行下述三个步骤：

　　首先，使用Resource Symbols对话（在View菜单中选择Resource Symbols．．．可以显示该对话）定义菜单项ID，该ID应大于0x0F而小于0xF000；
　　其次，调用CWnd::GetSystemMenu获取系统菜单的指针并调用CWnd:: Appendmenu将菜单项添加到菜单中。下例给系统菜单添加两个新的

int CMainFrame:: OnCreate (LPCREATESTRUCT lpCreateStruct)
{
    //…
    //Make sure system menu item is in the right range.
    ASSERT(IDM_MYSYSITEM<0xF000);
    //Get pointer to system menu.
    CMenu* pSysMenu=GetSystemMenu(FALSE);
    ASSERT_VALID(pSysMenu);
    //Add a separator and our menu item to system menu.
    CString StrMenuItem(_T ("New menu item"));
    pSysMenu->AppendMenu(MF_SEPARATOR);
    pSysMenu->AppendMenu(MF_STRING, IDM_MYSYSITEM, StrMenuItem);
    //…
}

十三、运行其它程序
　　1、运行EMAIL或网址

char szMailAddress[80];
strcpy(szMailAddress,"mailto:[e-mail]");
ShellExecute(NULL, "open", szMailAddress, NULL, NULL, SW_SHOWNORMAL);

　　2、运行可执行程序

WinExec("notepad.exe",SW_SHOW); //运行计事本

十四、动态增加或删除菜单
1、 增加菜单
添加

CMenu *mainmenu;
mainmenu=AfxGetMainWnd                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        ()->GetMenu(); //得到主菜单
(mainmenu->GetSubMenu (0))->AppendMenu (MF_SEPARATOR);//添加分隔符
(mainmenu->GetSubMenu (0))->AppendMenu(MF_STRING,ID_APP_ABOUT,
                                        _T("Always on &Top")); //添加新的菜单项
                                        DrawMenuBar(); //重画菜单

2、 删除菜单

删除

CMenu *mainmenu;
mainmenu=AfxGetMainWnd()->GetMenu(); //得到主菜单

CString str ;
for(int i=(mainmenu->GetSubMenu (0))->GetMenuItemCount()-1;i>=0;i--) //取得菜单的项数。
{
    (mainmenu->GetSubMenu (0))->GetMenuString(i,str,MF_BYPOSITION);
    //将指定菜单项的标签拷贝到指定的缓冲区。MF_BYPOSITION的解释见上。
    if(str=="Always on &Top") //如果是刚才我们增加的菜单项，则删除。
    {
        (mainmenu->GetSubMenu (0))->DeleteMenu(i,MF_BYPOSITION);
        break;
    }
}

十五、改变应用程序的图标静态更改：
　　修改图标资源IDR_MAINFRAME。它有两个图标，一个是16*16的，另一个是32*32的，注意要一起修改。

　　动态更改： 向主窗口发送WM_SETICON消息.代码如下：

HICON hIcon=AfxGetApp()->LoadIcon(IDI_ICON);
ASSERT(hIcon);
AfxGetMainWnd()->SendMessage(WM_SETICON,TRUE,(LPARAM)hIcon);

十六、另一种改变窗口标题的方法
　　使用语句 CWnd* m_pCWnd = AfxGetMainWnd( )，然后，再以如下形式调用SetWindowText()函数：

SetWindowText( *m_pCWnd,(LPCTSTR)m_WindowText);// m_WindowText可以是一个CString类的变量。

十七、剪切板上通过增强元文件拷贝图像数据
　　下面代码拷贝通过元文件拷贝图像数据到任何应用程序，

//其可以放置在CView派生类的函数中。

CMetaFileDC * m_pMetaDC = new CMetaFileDC();
m_pMetaDC->CreateEnhanced(GetDC(),NULL,NULL,"whatever");
//draw meta file
//do what ever you want to do: bitmaps, lines, text...
//close meta file dc and prepare for cliPBoard;
HENHMETAFILE hMF = m_pMetaDC->CloseEnhanced();
//copy to clipboard
OpenClipboard();
EmptyClipboard();
::SetClipboardData(CF_ENHMETAFILE,hMF);
CloseClipboard();

//DeleteMetaFile(hMF);
delete m_pMetaDC;

十八、剪切板上文本数据的传送把文本放置到剪接板上：
CString source;
//put your text in source
if(OpenCliPBoard())
{
    HGLOBAL clipbuffer;
    char * buffer;
    EmptyClipboard();
    clipbuffer = GlobalAlloc(GMEM_DDESHARE, source.GetLength()+1);
    buffer = (char*)GlobalLock(clipbuffer);
    strcpy(buffer, LPCSTR(source));
    GlobalUnlock(clipbuffer);
    SetClipboardData(CF_TEXT,clipbuffer);
    CloseClipboard();
}

//从剪接板上获取文本：

char * buffer;
if(OpenClipboard())
{
    buffer = (char*)GetClipboardData(CF_TEXT);
    //do something with buffer here
    //before it goes out of scope
}
CloseClipboard();

十九、将捕捉屏幕图像到剪切版中
void CShowBmpInDlgDlg::OnCutScreen()
{
    ShowWindow(SW_HIDE);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            RECT r_bmp={0,0,::GetSystemMetrics(SM_CXSCREEN),
        ::GetSystemMetrics(SM_CYSCREEN)};
    HBITMAP hBitmap;
    hBitmap=CopyScreenToBitmap(&r_bmp);
   
    //hWnd为程序窗口句柄
    if (OpenClipboard())
    {
        EmptyClipboard();
        SetClipboardData(CF_BITMAP, hBitmap);
        CloseClipboard();
    }
    ShowWindow(SW_SHOW);
}
HBITMAP CShowBmpInDlgDlg::CopyScreenToBitmap(LPRECT lpRect)
{
    //lpRect 代表选定区域
    {
        HDC hScrDC, hMemDC;
        // 屏幕和内存设备描述表
        HBITMAP hBitmap, hOldBitmap;
        // 位图句柄
        int nX, nY, nX2, nY2;
        // 选定区域坐标
        int nWidth, nHeight;
        // 位图宽度和高度
        int xScrn, yScrn;
        // 屏幕分辨率
       
        // 确保选定区域不为空矩形
        if (IsRectEmpty(lpRect))
            return NULL;
        //为屏幕创建设备描述表
        hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
        //为屏幕设备描述表创建兼容的内存设备描述表
        hMemDC = CreateCompatibleDC(hScrDC);
        // 获得选定区域坐标
        nX = lpRect->left;
        nY = lpRect->top;
        nX2 = lpRect->right;
        nY2 = lpRect->bottom;
        // 获得屏幕分辨率
        xScrn = GetDeviceCaps(hScrDC, HORZRES);
        yScrn = GetDeviceCaps(hScrDC, VERTRES);
        //确保选定区域是可见的
        if (nX<0)
           
            nX = 0;
        if (nY<0)
            nY = 0;
        if (nX2>xScrn)
            nX2 = xScrn;
        if (nY2>yScrn)
            nY2 = yScrn;
        nWidth = nX2 - nX;
        nHeight = nY2 - nY;
        // 创建一个与屏幕设备描述表兼容的位图
        hBitmap = CreateCompatibleBitmap
            (hScrDC, nWidth, nHeight);
        // 把新位图选到内存设备描述表中
        hOldBitmap =(HBITMAP)SelectObject(hMemDC, hBitmap);
        // 把屏幕设备描述表拷贝到内存设备描述表中
        BitBlt(hMemDC, 0, 0, nWidth, nHeight, hScrDC, nX, nY, SRCCOPY);
        //得到屏幕位图的句柄
        hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
       
        //清除
        DeleteDC(hScrDC);
        DeleteDC(hMemDC);
        // 返回位图句柄
        return hBitmap;
    }
}

二十、如何将位图缩放显示在Static控件中
//在Staic控件内显示位图
void CShowBmpInDlgDlg::ShowBmpInStaic()
{
    CBitmap hbmp;
    HBITMAP hbitmap;
    //将pStatic指向要显示的地方
    CStatic *pStaic;
    pStaic=(CStatic*)GetDlgItem(IDC_IMAGE);
    //装载资源 MM.bmp是我的一个文件名，用你的替换
    hbitmap=(HBITMAP)::LoadImage (::AfxGetInstanceHandle(),"MM.bmp",
        IMAGE_BITMAP,0,0,LR_LOADFROMFILE|LR_CREATEDIBSECTION);
   
    hbmp.Attach(hbitmap);
    //获取图片格式
    BITMAP bm;
    hbmp.GetBitmap(&bm);
    CDC dcMem;
    dcMem.CreateCompatibleDC(GetDC());
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            CBitmap *poldBitmap=(CBitmap*)dcMem.SelectObject(hbmp);
    CRect lRect;
    pStaic->GetClientRect(&lRect);
    //显示位图
    pStaic->GetDC()->StretchBlt(lRect.left ,lRect.top ,lRect.Width(),lRect.Height(),
        &dcMem,0 ,0,bm.bmWidth,bm.bmHeight,SRCCOPY);
    dcMem.SelectObject(&poldBitmap);
}