drawmenu.c

C#一个实例源代码

/*-----------------------------------------------------------------------------------------------------------
    DrawMenu.c
------------------------------------------------------------------------------------------------------------*/   
#define CITEMS 4
#include <windows.h>
#include "resource.h"
#define REGULAR 0
#define BOLD 1
#define ITALIC 2
#define ULINE 3

LRESULT CALLBACK MainWndProc (HWND, UINT, WPARAM, LPARAM) ;
HFONT GetAFont(int);
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("DrawMenu") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;

     wndclass.style         = CS_HREDRAW | CS_VREDRAW|CS_DBLCLKS;
     wndclass.lpfnWndProc   = MainWndProc ;
     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  = szAppName ;
     wndclass.lpszClassName = szAppName ;

     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"), 
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName,                
                          TEXT ("DrawMenu"), 
                          WS_OVERLAPPEDWINDOW
						  |WS_HSCROLL|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 APIENTRY MainWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) 
{ 
 
    typedef struct _MYITEM 
    { 
        HFONT hfont; 
        LPSTR psz; 
    } MYITEM;             // structure for item font and string  
 
    MYITEM *pmyitem;      // pointer to item's font and string        
    static MYITEM myitem[CITEMS];   // array of MYITEMS               
    static HMENU hmenu;             // handle to main menu            
    static COLORREF crSelText;  // text color of selected item        
    static COLORREF crSelBkgnd; // background color of selected item  
    COLORREF crText;            // text color of unselected item      
    COLORREF crBkgnd;           // background color unselected item   
    LPMEASUREITEMSTRUCT lpmis;  // pointer to item of data             
    LPDRAWITEMSTRUCT lpdis;     // pointer to item drawing data        
    HDC hdc;                    // handle to screen DC                
    SIZE size;                  // menu-item text extents             
    WORD wCheckX;               // check-mark width                   
    int nTextX;                 // width of menu item                 
    int nTextY;                 // height of menu item                
    int i;                      // loop counter                       
    HFONT hfontOld;             // handle to old font                 
    BOOL fSelected = FALSE;     // menu-item selection flag           
 
    switch (uMsg) 
    { 
        case WM_CREATE: 
 
            // Modify the Regular, Bold, Italic, and Underline 
            // menu items to make them owner-drawn items. Associate 
            // a MYITEM structure with each item to contain the 
            // string and font handle for each item. 
 
            hmenu = GetMenu(hwnd); 
            ModifyMenu(hmenu, IDM_REGULAR, MF_BYCOMMAND | 
                MF_CHECKED | MF_OWNERDRAW, IDM_REGULAR, 
                (LPTSTR) &myitem[REGULAR]); 

            ModifyMenu(hmenu, IDM_BOLD, MF_BYCOMMAND | 
                MF_OWNERDRAW, IDM_BOLD, (LPTSTR) &myitem[BOLD]);
			
            ModifyMenu(hmenu, IDM_ITALIC, MF_BYCOMMAND | 
                MF_OWNERDRAW, IDM_ITALIC, 
                (LPTSTR) &myitem[ITALIC]); 

            ModifyMenu(hmenu, IDM_ULINE, MF_BYCOMMAND | 
                MF_OWNERDRAW, IDM_ULINE, (LPTSTR) &myitem[ULINE]); 
 
            // Retrieve each item's font handle and copy it into 
            // the hfont member of each item's MYITEM structure. 
            // Also, copy each item's string into the structures. 
 
            myitem[REGULAR].hfont = GetAFont(REGULAR); 
            myitem[REGULAR].psz = "Regular"; 
            myitem[BOLD].hfont = GetAFont(BOLD); 
            myitem[BOLD].psz = "Bold"; 
            myitem[ITALIC].hfont = GetAFont(ITALIC); 
            myitem[ITALIC].psz = "Italic"; 
            myitem[ULINE].hfont = GetAFont(ULINE); 
            myitem[ULINE].psz = "Underline"; 
 
            // Retrieve the text and background colors of the 
            // selected menu text. 
 
            crSelText = GetSysColor(COLOR_HIGHLIGHTTEXT); 
            crSelBkgnd = GetSysColor(COLOR_HIGHLIGHT); 
 
            return 0; 
 
        case WM_MEASUREITEM: 
 
            // Retrieve a device context for the main window.  
 
            hdc = GetDC(hwnd); 
 
            // Retrieve pointers to the menu item's 
            // MEASUREITEMSTRUCT structure and MYITEM structure. 
 
            lpmis = (LPMEASUREITEMSTRUCT) lParam; 
            pmyitem = (MYITEM *) lpmis->itemData; 
 
            // Select the font associated with the item into 
            // the main window's device context. 
 
            hfontOld = SelectObject(hdc, pmyitem->hfont); 
 
            // Retrieve the width and height of the item's string, 
            // and then copy the width and height into the 
            // MEASUREITEMSTRUCT structure's itemWidth and 
            // itemHeight members. 
 
            GetTextExtentPoint32(hdc, pmyitem->psz, 
                lstrlen(pmyitem->psz), &size); 
            lpmis->itemWidth = size.cx; 
            lpmis->itemHeight = size.cy; 
 
            // Select the old font back into the device context, 
            // and then release the device context. 
 
            SelectObject(hdc, hfontOld); 
            ReleaseDC(hwnd, hdc); 
 
            return TRUE; 
 
            break; 
 
        case WM_DRAWITEM: 
 
            // Get pointers to the menu item's DRAWITEMSTRUCT 
            // structure and MYITEM structure. 
 
            lpdis = (LPDRAWITEMSTRUCT) lParam; 
            pmyitem = (MYITEM *) lpdis->itemData; 
 
            // If the user has selected the item, use the selected 
            // text and background colors to display the item. 
 
            if (lpdis->itemState & ODS_SELECTED) 
            { 
                crText = SetTextColor(lpdis->hDC, crSelText); 
                crBkgnd = SetBkColor(lpdis->hDC, crSelBkgnd); 
                fSelected = TRUE; 
            } 
 
            // Remember to leave space in the menu item for the 
            // check-mark bitmap. Retrieve the width of the bitmap 
            // and add it to the width of the menu item. 
 
            wCheckX = GetSystemMetrics(SM_CXMENUCHECK); 
            nTextX = wCheckX + lpdis->rcItem.left; 
            nTextY = lpdis->rcItem.top; 
 
            // Select the font associated with the item into the 
            // item's device context, and then draw the string. 
 
            hfontOld = SelectObject(lpdis->hDC, pmyitem->hfont); 
            ExtTextOut(lpdis->hDC, nTextX, nTextY, ETO_OPAQUE, 
                &lpdis->rcItem, pmyitem->psz, 
                lstrlen(pmyitem->psz), NULL); 
 
            // Select the previous font back into the device 
            // context. 
 
            SelectObject(lpdis->hDC, hfontOld); 
 
            // Return the text and background colors to their 
            // normal state (not selected). 
 
            if (fSelected) 
            { 
                SetTextColor(lpdis->hDC, crText); 
                SetBkColor(lpdis->hDC, crBkgnd); 
            } 
 
            return TRUE; 
 
        // Process other messages.  
 
        case WM_DESTROY: 
 
            // Destroy the menu items' font handles.  
 
            for (i = 0; i < CITEMS; i++) 
                DeleteObject(myitem[i].hfont); 
 
            PostQuitMessage(0); 
            break; 
 
        default: 
            return DefWindowProc(hwnd, uMsg, wParam, lParam); 
    } 
    return 0; 
} 
 
HFONT GetAFont(int fnFont) 
{ 
    static LOGFONT lf;  // structure for font information  
 
    // Get a handle to the ANSI fixed-pitch font, and copy 
    // information about the font to a LOGFONT structure. 
 
    GetObject(GetStockObject(ANSI_FIXED_FONT), sizeof(LOGFONT), 
        &lf); 
 
    // Set the font attributes, as appropriate.  
 
    if (fnFont == BOLD) 
        lf.lfWeight = FW_BOLD; 
    else 
        lf.lfWeight = FW_NORMAL; 
 
    lf.lfItalic = (fnFont == ITALIC); 
    lf.lfUnderline = (fnFont == ULINE); 
 
    // Create the font, and then return its handle.  
 
    return CreateFont(lf.lfHeight, lf.lfWidth, 
        lf.lfEscapement, lf.lfOrientation, lf.lfWeight, 
        lf.lfItalic, lf.lfUnderline, lf.lfStrikeOut, lf.lfCharSet, 
        lf.lfOutPrecision, lf.lfClipPrecision, lf.lfQuality, 
        lf.lfPitchAndFamily, lf.lfFaceName); 
}