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电梯直达

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发表于 2016-06-06 14:18 |只看该作者 |倒序浏览

template <>
struct CameraTraits<Camera>
{
typedef CameraListener       TCamListener;
typedef ICamera             TCamUser;
typedef ICameraClient       TCamCallbacks;
typedef status_t (ICameraService::*TCamConnectService)(const sp<ICameraClient>&,  //这个定义一个函数指针
                                                         int, const String16&, int,
                                                         /*out*/
                                                         sp<ICamera>&);
static TCamConnectService    fnConnectService;
};

CameraTraits<Camera>::TCamConnectService CameraTraits<Camera>::fnConnectService =  //函数指针赋值
      &ICameraService::connect;

TCamConnectService fnConnectService = TCamTraits::fnConnectService;
status = (cs.get()->*fnConnectService)(cl, cameraId, clientPackageName, clientUid,  //调用函数指针所指向的函数，这块我有点蒙逼了，->*是什么鬼？这个不是个语法错误吗？
                                       /*out*/ c->mCamera);

我所理解的应该是这样:
status = *(cs.get()->fnConnectService)(cl, cameraId, clientPackageName, clientUid,  //不应该是这样写吗？
                                       /*out*/ c->mCamera);