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copied!<p>I couldn't resist doing it. </p> <p>It's your code with added timers and implemented a fade in / fade out. Also I changed to use mid grey rather than black for the obscuring block. </p> <p>You can tweak the constants that control the fade to make it smoother by increasing the duration or the increasing the rate. Experiment shows me that a rate of 10hz is smooth for me, but YMMV</p> <pre><code>// DimWnd.h : header file #pragma once class CDimWnd : public CFrameWnd { public: CDimWnd(class CWnd * pParent); virtual ~CDimWnd(); BOOL OnEraseBkgnd(CDC* pDC); int opacity, opacity_increment; protected: DECLARE_MESSAGE_MAP() public: afx_msg void OnTimer(UINT_PTR nIDEvent); void fadeOut(); }; </code></pre> <hr> <pre><code>// DimWnd.cpp : implementation file // #include "stdafx.h" #include "dimmer.h" #include "DimWnd.h" #include "MainFrm.h" #include <math.h> const int TIMER_ID = 111; // For preventing two dimmer windows ever appearing bool is_dimmer_active = false; // constants to control the fade. int ticks_per_second = 1000; // ms int start_opacity = 44; // 20% int max_opacity = 220; // 0->255 double fade_in_duration = 4; // seconds to fade in (appear) double fade_out_duration = 0.2; // seconds to fade out (disappear) int rate = 100; // Timer rate (ms CDimWnd::CDimWnd(CWnd * pParent) { // Don't do anything if the main frame doesn't appear to be there, // or if there is already dimming happening. if (pParent != NULL && !is_dimmer_active) { // Get the client area of the window to dim. CRect rc; pParent->GetClientRect(&rc); pParent->ClientToScreen(&rc); // convert to screen coordinates // Do some fudging to fit the client area exactly. // Other applications may not need this if the above client area fits already. rc.top += GetSystemMetrics(SM_CYFRAME); rc.top += GetSystemMetrics(SM_CYCAPTION); // MFC feature pack seems to include caption in client area rc.left -= GetSystemMetrics(SM_CXBORDER); rc.right += GetSystemMetrics(SM_CXBORDER) + 1; rc.bottom += GetSystemMetrics(SM_CYBORDER) + 1; // Create a layered window for transparency, with no caption/border. CreateEx(WS_EX_LAYERED | WS_EX_TRANSPARENT | WS_EX_TOOLWINDOW, NULL, TEXT(""), WS_POPUP, rc.left, rc.top, rc.Width(), rc.Height(), pParent->GetSafeHwnd(), NULL); // Bring in front of main window. BringWindowToTop(); // Show the dimmer window ShowWindow(SW_SHOW); double increment_per_second = ((max_opacity - start_opacity) / fade_in_duration); opacity_increment = ceil( increment_per_second / (ticks_per_second / rate) ) ; is_dimmer_active = true; opacity = start_opacity; SetLayeredWindowAttributes(RGB(0,0,0), opacity, LWA_ALPHA); SetTimer(TIMER_ID, rate,NULL); } } CDimWnd::~CDimWnd() { fadeOut(); // fade the window out rather than just disappearing. is_dimmer_active = false; } void CDimWnd::fadeOut() { // can't use timers as may be in the process of being destroyed so make it quick.. double increment_per_second = ((opacity - start_opacity) / fade_out_duration); opacity_increment = ceil( increment_per_second / (ticks_per_second / rate) ) ; while(opacity > start_opacity) { opacity -= opacity_increment; SetLayeredWindowAttributes(RGB(0,0,0), opacity, LWA_ALPHA); Sleep(100); } } BOOL CDimWnd::OnEraseBkgnd(CDC* pDC) { // Fill with midgray CBrush backBrush(RGB(128,128,128)); CBrush* pOldBrush = pDC->SelectObject(&backBrush); CRect rect; pDC->GetClipBox(&rect); // Erase the area needed pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(), PATCOPY); pDC->SelectObject(pOldBrush); return TRUE; } BEGIN_MESSAGE_MAP(CDimWnd, CFrameWnd) ON_WM_ERASEBKGND() ON_WM_TIMER() END_MESSAGE_MAP() void CDimWnd::OnTimer(UINT_PTR nIDEvent) { if (opacity >= max_opacity) { // stop the timer when fade in finished. KillTimer(TIMER_ID); return; } opacity += opacity_increment; SetLayeredWindowAttributes(RGB(0,0,0), opacity, LWA_ALPHA); CFrameWnd::OnTimer(nIDEvent); } </code></pre>

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