在網頁中只需要加入以下代碼
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="600" height="60">
<param name="movie" value="test.swf">
<param name="quality" value="high">
<param name="wmode" value="transparent">
<embed src="***.swf" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="600" height="60"></embed>
</object>
就可以實現 Flash 背景透明
在VC中要實現 Flash 背影透明播放，Google了一下找到一個 Demo
原文URL：
http://www.codeproject.com/KB/COM/flashcontrol.aspx需要自己實現一個OLE容器，以前很少接觸COM，現在要實現的是一個OLE容器，先汗一下！！！！
想到一個問題：自己實現一個OLE容器跟使用直接使用FlashOcx 控件有何不同？
-- 未解決
Part 1
實現一個ActiveX對象的OLE容器需要繼承幾個接口
IOleClientSite
IOleInPlaceSiteWindowless
IOleInPlaceFrame
IStorage
(具體做什么，需要找資料惡補一下~~~~ ActiveX, OLE容器……)
在DEMO里實現了一個OLE容器類叫 COleContainerWnd
template<CLASS T>
class COleContainerWnd : virtual public IOleClientSite,
virtual public IOleInPlaceSiteWindowless,
virtual public IOleInPlaceFrame,
virtual public IStorage
是個模板類，T是留給 ActiveX 的接口
Part 2
把 flash.ocx 引進來，因為里面包含了Flash播放器的相關接口定義，它就是我們要放到容器里的 ActiveX 對象了
#import "flash.ocx" named_guids
Part 3
CFlashWnd派生類
class CFlashWnd: public COleContainerWnd<ShockwaveFlashObjects::IShockwaveFlash>,
public ShockwaveFlashObjects::_IShockwaveFlashEvents,
public ShockwaveFlashObjects::IServiceProvider
再汗一下，CFlashWnd 是個容器，還要實現 public ShockwaveFlashObjects::IServiceProvider 接口作甚？
至于要繼承 ShockwaveFlashObjects::_IShockwaveFlashEvents 接口的目的是為了接收 Flash 動畫發過來的 fscommand() 事件，在 Flash的AS（動作腳本）中調用 FsCommand()，就會
觸發這個事件了
(這是一個精通 Flash 的同學告訴我的！！)
CFlashWnd 對象的創建
g_flashWnd = new CFlashWnd;
g_flashWnd->Create(ShockwaveFlashObjects::CLSID_ShockwaveFlash,
WS_EX_LAYERED, WS_POPUP | WS_VISIBLE | WS_CLIPSIBLINGS,
g_hWnd, g_hInst);
Create() 函數的第一個參數：Flash 播放對象的ClassID
Create() 函數的第二個參數：窗體的擴展風格 WS_EX_LAYERED ，據說加了這個風格才能實現透明 Flash ，為啥？
……
Part 4
CFlashWnd::Create() 的內幕
注冊了窗口類，然后就 CreateWindows 了
值得注意的是
OleCreate() 函數用來創建一個 IOleObject 對象的實例，需要 把 Ole 容器 的 IOleClientSite 和 IStorage 作為參數傳給它
hr = OleCreate(m_CLSID, IID_IOleObject, OLERENDER_DRAW,
0, (IOleClientSite *)this, (IStorage *)this, (void **)&m_lpO);
hr = OleSetContainedObject(m_lpO, TRUE);
OleSetContainedObject () 函數通知 IOleObject 對象跟它說，你已經被嵌到 OLE 容器里了
hr = m_lpO->QueryInterface(__uuidof(T), (void **)&m_lpControl);
然后用 IOleObject 的 QueryInterface 獲取 IShockwaveFlash 接口（那個 T, 就是 ShockwaveFlashObjects::IShockwaveFlash 了）
hr = m_lpO->QueryInterface(IID_IViewObjectEx, (void **)&m_lpViewObjectEx);
同樣的方法，也得到了 IViewObjectEx 的接口
IViewObjectEx 用來干嘛的？？
要創建一個無窗口的控件，OLE容器需要 IOleInPlaceObjectWindowless 接口來分派消息給對象, 因為 對象本身沒有自己所屬的窗體
另外，IOleInPlaceObject 接口需要重出那個對象
hr = m_lpO->DoVerb(OLEIVERB_SHOW, NULL, (IOleClientSite *)this, 0, NULL, NULL);
IOleObject::DoVerb() 用來顯示對象和將對象置為運行的狀態
這樣，Flash 播放對象就建好了.....
Part 5.
透明窗體的重畫
1、創建窗體時加上 WS_EX_LAYERED 屬性
2、用 CreateDIBSection() 創建一個 32位的DIB塊, 然后把它 Select 到 DC 里面, It will be an offscreen plain to render window contents to. (這句不知如何譯....)
3、描繪窗體的內容, preserving the alpha channel. (同上..)
4、調用 UpdateLayeredWindow() 函數重畫窗體
描繪 Flash 播放的內容，用 OleDraw() 函數, 在 IViewObject::Draw() 中調用
hr = OleDraw(lpV, DVASPECT_TRANSPARENT, hdcDraw, &rTotal);
lpV – IViewObject interface of flash player control
hdcDraw – offscreen plain
rTotal – client rectangle of the container window
DVASPECT_TRANSPARENT drawing aspect tells the object to draw it's content using alpha blending.
DVASPECT_TRANSPARENT drawing aspect tells the object to draw it's content using alpha blending.
While implementing this, I have met a serious bug in Flash Player Control 8. This bug is only in this version. Players 7 and 9 are free of it. The bug is in the way Flash Control fills the alpha channel of a 32 bit device context. If at least 1 of 255 alpha values is applied to pixel, the colors are mixed correctly, but the resulting alpha channel is set to 255, even if it was initially zero. This makes it impossible to create semitransparent windows. So I had to develop a solution to fix this bug. The solution is quite simple:
These equations are used by Flash Player Control for alpha blending:
R' = Rdst * (1 – alpha) + Rsrc * alpha
G' = Gdst * (1 – alpha) + Gsrc * alpha
B' = Bdst * (1 – alpha) + Bsrc * alpha
If I draw the contents of Flash onto black surface I get
R'black = Rsrc * alpha
G'black = Gsrc * alpha
B'black = Bsrc * alpha
If I draw the contents of Flash onto white surface I get
R'white = 255 * (1 – alpha) + Rsrc * alpha
G'white = 255 * (1 – alpha) + Rsrc * alpha
B'white = 255 * (1 – alpha) + Rsrc * alpha
Here is the system of equations:
R'black = Rsrc * alpha
R'white = 255 * (1 – alpha) + Rsrc * alpha
where alpha and Rsrc are unknown. After solving it you will get:
(255-Alpha) = R'white – R'black
Alpha = 255 – (R'white – R'black) So, the solution is found. Now, we can draw contents of flash player twice and then correct the corrupted alpha channel.
Part 6. Events
Flash Player 對象的事件是用IDispatch來處理的，在創建后得到一個 IConnectionPointContainer 去獲取 DIID__IShockwaveFlashEvents 的 連接點(connection point)
hr = m_lpControl->QueryInterface(IID_IConnectionPointContainer,
(void**)&m_lpConCont);
if (FAILED(hr))
return FALSE;
hr = m_lpConCont->FindConnectionPoint(
ShockwaveFlashObjects::DIID__IShockwaveFlashEvents, &m_lpConPoint);
if (FAILED(hr))
return FALSE;
hr = m_lpConPoint->Advise(
(ShockwaveFlashObjects::_IShockwaveFlashEvents*)this,
&m_dwConPointID);
if (FAILED(hr))
return FALSE;
Part 7. DirectDraw
為了提交重畫的性能，所以使用 DirectDraw 接口
Flash對象通過 ShockwaveFlashObjects::IServiceProvider::raw_RemoteQueryService 這個接口來訪問它
(需要找一下 FlashObject 接口的文檔了解一下)
（眼睛睜不開，需要先睡一會………………）