error LNK2001: unresolved external symbol public: static class
c++, linker-errors, static-members
Solution
In a class definition, `static` variables are a merely a declaration. You have only declared that `capture` will exist somewhere.
You need to add the definition. Make the variable exist.
In any version of C++
You can separately define the variable in your cpp file.
const VideoCapture Video::capture;
In C++ 17 or later
You can declare the variable `inline` in your header to make it a definition.
static inline VideoCapture capture;
Problem
I cannot figure out why i am recieving this error. Can anyone lend a hand. I need to declare VideoCapture capture in the header file and call it in Video.cpp Video.h ``` class Video { public: static VideoCapture capture; //Default constructor Video(); //Declare a virtual destructor: virtual ~Video(); //Method void Start(); private: }; ``` Video.cpp ``` #include "StdAfx.h" #include "Video.h" #include "UserInfo.h" #include "Common.h" void Video::Start() { while(1) { Mat img; bool bSuccess = capture.read(img); // read a new frame from video if (!bSuccess) //if not success, break loop { cout << "End of video" << endl; break; } imshow("original video", img); //show the frame in "Original Video" window if(waitKey(30) == 27) //wait for 'esc' key press for 30 ms. If 'esc' key is pressed, break loop { cout << "esc key is pressed by user" << endl; break; } } } ``` Any help would be greatly appreciated