I'm dealing with sample code from a camera SDK, and I have issues getting the frame data "outside" the CSampleCaptureEventHandler class.

class DahengCamera : public QObject
{
    Q_OBJECT

    class CSampleCaptureEventHandler : public ICaptureEventHandler
    {       
        void DoOnImageCaptured(CImageDataPointer& objImageDataPointer, void* pUserParam)
        {
            [grab some data ...]
        
            CopyToImage(objImageDataPointer);  // illegal call of non-static member function
        }

    };


public:
    DahengCamera();
    ~DahengCamera();
    
private:
   
    void CopyToImage(CImageDataPointer pInBuffer);  // I want to have my frame datas here

    QImage m_data; //and here

};

I'm using a callback register call to make the camera "DoOnImageCaptured" event called once a frame is grabbed by the system. But I'm stuck getting the data outside this method. CopyToImage() is supposed to get a reference to QImage or to write into m_data, but I have "illegal call of non-static member function" errors. Tried to make CopyToImage() static, but it just move the problem...

How can I solve this ?

Thanks !

CodePudding user response：

CopyToImage is a private non-static function in the class DahengCamera.
The fact that CSampleCaptureEventHandler is a nested class inside DahengCamera allows it to access DahengCamera's private members and functions (as if it were decleared a friend class), but this does not provide CSampleCaptureEventHandler with a pointers to any DahengCamera objects.

You need to provide the actual instance of the CSampleCaptureEventHandler object on which DoOnImageCaptured is called with a pointer/refence to the DahengCamera object on which CopyToImage should be called. You might consider providing this pointer/reference to the DoOnImageCaptured object to CSampleCaptureEventHandler's constuctor (i.e. dependency injection).

(And - for your own sake - do not try to "fix" this by turning CopyToImage or m_data into static - this would create only a horrible mess)