• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>
            隨筆 - 3  文章 - 3  trackbacks - 0
            <2025年5月>
            27282930123
            45678910
            11121314151617
            18192021222324
            25262728293031
            1234567

            常用鏈接

            留言簿(1)

            隨筆分類

            隨筆檔案

            相冊

            News

            Program

            搜索

            •  

            最新評論

            閱讀排行榜

            評論排行榜

            Superclassing is a technique that allows an application to create a new window class with the basic functionality of the existing class, plus enhancements provided by the application. A superclass is based on an existing window class called the base class. Frequently, the base class is a system global window class such as an edit control, but it can be any window class.

            A superclass has its own window procedure, called the superclass procedure. The superclass procedure can take three actions upon receiving a message: It can pass the message to the original window procedure, modify the message and pass it to the original window procedure, or process the message and not pass it to the original window procedure. If the superclass procedure processes a message, it can do so before, after, or both before and after it passes the message to the original window procedure.

            Unlike a subclass procedure, a superclass procedure can process window creation messages (WM_NCCREATE, WM_CREATE, and so on), but it must also pass them to the original base-class window procedure so that the base-class window procedure can perform its initialization procedure.

            To superclass a window class, an application first calls the GetClassInfo function to retrieve information about the base class. GetClassInfo fills a WNDCLASS structure with the values from the WNDCLASS structure of the base class. Next, the application copies its own instance handle into the hInstance member of the WNDCLASS structure and copies the name of the superclass into the lpszClassName member. If the base class has a menu, the application must provide a new menu with the same menu identifiers and copy the menu name into the lpszMenuName member. If the superclass procedure processes the WM_COMMAND message and does not pass it to the window procedure of the base class, the menu need not have corresponding identifiers. GetClassInfo does not return the lpszMenuName, lpszClassName, or hInstance member of the WNDCLASS structure.

            An application must also set the lpfnWndProc member of the WNDCLASS structure. The GetClassInfo function fills this member with the address of the original window procedure for the class. The application must save this address, to pass messages to the original window procedure, and then copy the address of the superclass procedure into the lpfnWndProc member. The application can, if necessary, modify any other members of the WNDCLASS structure. After it fills the WNDCLASS structure, the application registers the superclass by passing the address of the structure to the RegisterClass function. The superclass can then be used to create windows.

            Because superclassing registers a new window class, an application can add to both the extra class bytes and the extra window bytes. The superclass must not use the original extra bytes for the base class or the window for the same reasons that an instance subclass or a global subclass should not use them. Also, if the application adds extra bytes for its use to either the class or the window instance, it must reference the extra bytes relative to the number of extra bytes used by the original base class. Because the number of bytes used by the base class may vary from one version of the base class to the next, the starting offset for the superclass's own extra bytes may also vary from one version of the base class to the next.

            posted @ 2008-06-01 17:39 陳振輝 閱讀(355) | 評論 (0)編輯 收藏
                     When you implement a modeless dialog box, always override the OnCancel member function and call DestroyWindow from within   it. Don’t call the base class CDialog::OnCancel, because it calls EndDialog, which will make the dialog box invisible but will not destroy it. 
                     You should also override PostNcDestroy for modeless dialog boxes in order to delete this, since modeless dialog boxes are usually allocated with new. Modal dialog boxes are usually constructed on the frame and do not need PostNcDestroy cleanup.
            posted @ 2008-04-14 10:19 陳振輝 閱讀(901) | 評論 (3)編輯 收藏

            Z-Order

            The z-order of a window indicates the window's position in a stack of overlapping windows. This window stack is oriented along an imaginary axis, the z-axis, extending outward from the screen. The window at the top of the z-order overlaps all other windows. The window at the bottom of the z-order is overlapped by all other windows.

            The system maintains the z-order in a single list. It adds windows to the z-order based on whether they are topmost windows, top-level windows, or child windows. A topmost window overlaps all other non-topmost windows, regardless of whether it is the active or foreground window. A topmost window has the WS_EX_TOPMOST style. All topmost windows appear in the z-order before any non-topmost windows. A child window is grouped with its parent in z-order.

            When an application creates a window, the system puts it at the top of the z-order for windows of the same type. You can use the BringWindowToTop function to bring a window to the top of the z-order for windows of the same type. You can rearrange the z-order by using the SetWindowPos and DeferWindowPos functions.

            The user changes the z-order by activating a different window. The system positions the active window at the top of the z-order for windows of the same type. When a window comes to the top of z-order, so do its child windows. You can use the GetTopWindow function to search all child windows of a parent window and return a handle to the child window that is highest in z-order. The GetNextWindow function retrieves a handle to the next or previous window in z-order.

            posted @ 2008-04-07 14:24 陳振輝| 編輯 收藏
            僅列出標題  
            久久国产高清一区二区三区| 久久久久久久波多野结衣高潮| 久久精品卫校国产小美女| 欧美精品乱码99久久蜜桃| 人妻无码αv中文字幕久久琪琪布| 亚洲精品tv久久久久久久久| 国产精品久久久久久吹潮| 国内精品欧美久久精品| 精品一二三区久久aaa片| 国产精品一久久香蕉产线看| 久久亚洲国产成人影院网站| 伊人久久大香线蕉av一区| 久久精品成人| 精品久久久久久久无码 | 香港aa三级久久三级老师2021国产三级精品三级在 | 日日狠狠久久偷偷色综合96蜜桃 | 伊人久久久AV老熟妇色| 天天爽天天爽天天片a久久网| 国产精品久久新婚兰兰| 亚洲嫩草影院久久精品| 精品久久久无码21p发布 | 久久久久久综合网天天| 久久www免费人成精品香蕉| 久久精品国产亚洲AV无码娇色| 香蕉99久久国产综合精品宅男自 | 国产精品欧美亚洲韩国日本久久 | 2021精品国产综合久久| 久久久午夜精品福利内容| 久久精品国产99国产精品澳门| 久久久久久综合网天天| 亚洲精品NV久久久久久久久久| 欧美久久久久久精选9999| 9久久9久久精品| 国产美女久久精品香蕉69| 无码AV波多野结衣久久| A级毛片无码久久精品免费| 亚洲婷婷国产精品电影人久久| 亚洲精品无码久久久久AV麻豆| 久久精品国产欧美日韩| 久久久受www免费人成| 青青青青久久精品国产h久久精品五福影院1421 |