[绘图界面库] Fortran适合科学计算，同时也能编写图形用户界面！

Module VarGlob
    integer( kind = 4 ) ::  results  ! 存储函数的返回值 
    logical( kind = 4 ) ::  logicalt  ! 存储函数的返回值 
End Module VarGlob

! windowing程序开始执行的地方(操作系统自动识别)
integer function WinMain( hInstance, hPrevInstance, lpszCmdLine, nCmdShow )
    !DEC$ IF DEFINED(_X86_)
    !DEC$ ATTRIBUTES STDCALL, ALIAS : '_WinMain@16' :: WinMain
    !DEC$ ELSE
    !DEC$ ATTRIBUTES STDCALL, ALIAS : 'WinMain' :: WinMain
    !DEC$ ENDIF

    USE IFWIN  !包含有用的模块
    USE VarGlob  !有用的数据模块
    Implicit None

    integer( kind = 4 ) ::  hInstance  !定义窗口的实例
    integer( kind = 4 ) ::  hPrevInstance  !定义句柄
    integer( kind = 4 ) ::  nCmdShow  !窗口的显示方式
    integer( kind = 4 ) ::  lpszCmdLine  !指向字符串的指针

    !定义函数接口，注意这一段是必须的
    interface 
    integer*4 function MainWndProc ( hwnd, message, wParam, lParam )
    !DEC$ IF DEFINED(_X86_)
    !DEC$ ATTRIBUTES STDCALL, ALIAS : '_MainWndProc@16' :: MainWndProc
    !DEC$ ELSE
    !DEC$ ATTRIBUTES STDCALL, ALIAS : 'MainWndProc' :: MainWndProc
    !DEC$ ENDIF
    integer( kind = 4 ) ::   hwnd 
    integer( kind = 4 ) ::  message  
    integer( kind = 4 ) ::  wParam
    integer( kind = 4 ) ::   lParam 
    end function  MainWndProc
    end interface

    type (T_WNDCLASS) :: wc  !窗口类结构体  
    type (T_MSG) :: msg   !消息结构体
    integer( kind = 4 ) :: hWnd
    character*100 lpszClassName,lpszAppName

    lpszClassName = "Generic"C   !窗口类名
    lpszAppName = "windowing程序框架"C  !窗口标题

    if(hPrevInstance .eq. 0) then
        wc%lpszClassName = LOC(lpszClassName)  !窗口类名
        wc%lpfnWndProc = LOC(MainWndProc)  !窗口回调函数
        wc%style = IOR(CS_VREDRAW , CS_HREDRAW) !窗口风格
        wc%hInstance = hInstance  !窗口实例
        wc%hIcon = LoadIcon( NULL, IDI_WINLOGO)  !程序图标
        wc%hCursor = LoadCursor( NULL, IDC_CROSS )  !程序光标
        wc%hbrBackground = GetStockObject(BLACK_BRUSH)  !窗口背景颜色
        wc%lpszMenuName = 0  !菜单名
        wc%cbClsExtra = 0  !无附加消息
        wc%cbWndExtra = 0
        results = RegisterClass(wc)  !注册窗口类
    end if

    !创建窗口
    hWnd = CreateWindowEx(0,                       	&  !窗口扩展样式
                 lpszClassName,                 	&  !窗口类名
                 lpszAppName,                  	&  !窗口标题
                 INT(WS_OVERLAPPEDWINDOW),	&  !窗口的风格
                 CW_USEDEFAULT,             	&  !左上角坐标X
                 0,                            	&  !左上角坐标Y
                 CW_USEDEFAULT,                 &  !窗口宽度尺寸
                 0,                             	&  !窗口高度尺寸
                 NULL,                         	&  !父窗口句柄
                 NULL,                     	     &  !主菜单句柄
                 hInstance,                  	     &  !窗口实例句柄
                 NULL  	                        &  !附加信息的指针
                 )

    !显示窗口
    results = ShowWindow( hWnd, SW_SHOWNORMAL) 
    !进入消息循环
    do while( GetMessage (msg, NULL, 0, 0) .NEQV. .FALSE.)
     results = TranslateMessage( msg ) !翻译消息
     results = DispatchMessage( msg ) !将消息传给windows,然后由windows传给回调函数
    end do
    WinMain = msg%wParam
End function WinMain

    
integer function MainWndProc ( hWnd, message, wParam, lParam )
    !DEC$ IF DEFINED(_X86_)
    !DEC$ ATTRIBUTES STDCALL, ALIAS : '_MainWndProc@16' :: MainWndProc
    !DEC$ ELSE
    !DEC$ ATTRIBUTES STDCALL, ALIAS : 'MainWndProc' :: MainWndProc
    !DEC$ ENDIF

    USE IFWIN  !包含有用的模块
    USE VarGlob  !有用的数据模块
    Implicit None

    integer( kind = 4 ) ::   hwnd 
    integer( kind = 4 ) ::  message  
    integer( kind = 4 ) ::  wParam
    integer( kind = 4 ) ::   lParam 

    select case ( message )
         case (WM_DESTROY)
            call PostQuitMessage( 0 )
         case default
            MainWndProc = DefWindowProc( hWnd, message, wParam, lParam )
    end select
end function MainWndProc