【第三步】实现IWMPPluginUI等接口
class CMediaPlayerPlugin:
public IWMPPluginUI
在上一篇文章中我列出了这个接口下的方法：
STDMETHODIMP Create(HWND hwndParent, HWND * phwndWindow);
STDMETHODIMP Destroy();
STDMETHODIMP DisplayPropertyPage(HWND hwndParent);
STDMETHODIMP GetProperty(LPCWSTR wszName, VARIANT * pvarProperty);
STDMETHODIMP SetCore(IWMPCore * pCore);
STDMETHODIMP SetProperty(LPCWSTR wszName, const VARIANT * pvarProperty);
STDMETHODIMP TranslateAccelerator(MSG * pMsg);
对于这些方法，实现你需要的，不感兴趣的仅仅让它为空即可，比如：
HRESULT CMediaPlayerPlugin::Create(HWND hwndParent, HWND * phwndWindow)
{
// As per the IWMPPluginUI documentation, this method will never be called
// because we're a background plugin (our registry Capabilities flags include
// PLUGIN_TYPE_BACKGROUND = 0x00000001).
return E_NOTIMPL;
}
SetCore是个关键方法，因为我们需要通过它获得操作WMP的接口指针，这里我们把获得的指针存放在m_pCore中：
HRESULT CMediaPlayerPlugin::SetCore(IWMPCore * pCore)
{
// This method is called shortly after this instance is created, and allows
// us to hook up to Windows Media Player. Save the interface pointer.
//
// When WMP is shutting down, it calls SetCore(NULL) so we have to handle that
// as well.
if (m_pCore != NULL)
{
m_pCore->Release();
}
m_pCore = pCore;
if (m_pCore != NULL)
{
m_pCore->AddRef();
}
return S_OK;
}
然后我们可以像这样进一步通过m_pCore获得其它接口指针，类似这里的get_contronls方法的还有get_settings等，更详细的可以查看附件的项目。
VOID CMediaPlayerPlugin::ControlPlayer(UINT uMsg)
{
IWMPControls * pControls;
// Get the 'IWMPControls' interface.
if (SUCCEEDED(m_pCore->get_controls(&pControls)))
{
switch (uMsg)
{
// for the toggle message
case WM_WMPTOGGLE:
WMPPlayState wmpps;
// get the current state
if (SUCCEEDED(m_pCore->get_playState(&wmpps)))
{
// if it playing a track, pause it
if (wmpps == wmppsPlaying)
{
pControls->pause();
}
// otherwise try to play the track
else
{
pControls->play();
}
}
break;
case WM_WMPPREVIOUS:
pControls->previous();
break;
case WM_WMPNEXT:
pControls->next();
break;
default:
break;
}
pControls->Release();
}
}
文章上个星期就写的差不多了，一直拖到现在才发布，实在抱歉。下一篇文章我总结下Today Plugin的开发。随便介绍下通过Today Plugin控制WMP。希望对你有所帮助，我的QQ是3423 6777 6，如果你需要什么帮助，或者跟我讨论的话。
