首先我们在.h文件中声明一些我们要用的变量和函数

 public:
  void DoSomething();

  void Start(TTimeIntervalMicroSeconds32 aInterval);
  void Stop();

  static TInt Tick(TAny* aThis);

 private:
  CPeriodic* iTicker;

然后是.cpp中的实现

在ConstructL()中添加iTicker的初始化

    iTimer = CTimeOutTimer::NewL( EPriorityHigh, *this );
    CActiveScheduler::Add( this );

其余函数的实现

void CSocketsEngine::Stop()
{
 if(iTicker)
 {
  iTicker->Cancel();
  delete iTicker;
  iTicker = NULL;
  iTicker = CPeriodic::NewL(CActive::EPriorityIdle);
 }
}

TInt CSocketsEngine::Tick(TAny* aThis)
{
 static_cast<CSocketsEngine*>(aThis)->GetNetworkStrength(0);
 return 0;
}

void CSocketsEngine::Start(TTimeIntervalMicroSeconds32 aInterval)
{
 if(iTicker)
 {
  iTicker->Cancel();
  delete iTicker;
  iTicker = NULL;
  iTicker = CPeriodic::NewL(CActive::EPriorityIdle);
 }

 iTicker->Start(aInterval, aInterval, TCallBack(Tick, this));
}

  void CSocketsEngine::DoSomething()

{

//做我们要做的事

}