C++技巧之四

代码清单2 window_redraw_scope的节略本

/* /////////////////////////////////////////////////////////////

 *

 * ...

 *

 * Extract from winstl_window_redraw_scope.h  

*摘录自winstl_window_redraw_scope.h

 *

 * www:        http://www.synesis.com.au/winstl

 *             http://www.winstl.org/

 *

 * Copyright (C) 2002, Synesis Software Pty Ltd.

 *版权所有(C) 2002, Synesis Software Pty Ltd公司

 * (Licensed under the Synesis Software Standard Source License:

 *  http://www.synesis.com.au/licenses/ssssl.html)

* (由Synesis Software Standard Source License授权许可:

 *  http://www.synesis.com.au/licenses/ssssl.html)

 *

 * ...

 *

 * ////////////////////////////////////////////////////////// */

...

namespace winstl

{

    class window_redraw_scope

    {

// Construction 

// 构造

    public:

        // Takes a HWND and changes it's current redraw-status,

        // which is set back to the original state in the 

        // destructor. 

       //取得HWND 句柄并改变其当前重画状态，在析构器中设置其回到初始状态。

        ws_explicit_k window_redraw_scope(HWND hwnd, 

                        ws_bool_t bInvalidateOnUnlock = true)

            : m_hwnd(hwnd)

            , m_bInvalidateOnUnlock(bInvalidateOnUnlock)

        {

            ::SendMessage(m_hwnd, WM_SETREDRAW, false, 0L);

        }

        ~window_redraw_scope() winstl_throw_0()

        {

            ::SendMessage(m_hwnd, WM_SETREDRAW, true, 0L);

            if(m_bInvalidateOnUnlock)

            {

                ::InvalidateRect(m_hwnd, NULL, true);

            }

        }

// Members 

// 成员变量

    protected:

        HWND        m_hwnd;

        ws_bool_t   m_bInvalidateOnUnlock;

// Not to be implemented

// 不被实现

    private:

        window_redraw_scope(window_redraw_scope const &rhs);

        window_redraw_scope const 

            &operator =(window_redraw_scope const &rhs);

    };

} // namespace winstl 名称空间

 

图表 1 Window作用域(scope)例子