判断程序是否运行在前台

// .lib
...
LIBRARY ws32.lib // for RWindowGroup
LIBRARY apgrfx.lib // for CApaWindowGroupName

// .cpp
...
#include <apgwgnam.h> // for CApaWindowGroupName
...
const TUid KUidMessagingApp = {0x100058C5};
RWsSession ws = iCoeEnv->WsSession();
TInt wgid = ws.GetFocusWindowGroup();
CApaWindowGroupName* gn = CApaWindowGroupName::NewLC(ws, wgid);
TUid uid = gn->AppUid();
CleanupStack::PopAndDestroy(gn);
if(uid==KUidMessagingApp)
{
// do something
}
...