How to build a moving graph from file data using a third-party Line Graph Component control?

Question

C++ / C#

I found a control on the code project for building time-moving graphs Line Graph Component (by Sandeep sunku), because my own chart is not displayed as it should, but I don’t know how to use it, although I already have it on the panel - even when I try to save a file with this stray, it gives a null reference error. The test program from the author's project does not draw any lines - it did not find any methods that load data from a file, only Buffer buffer and buffer.GetIndex(). Can you clarify the position? I mean - it should be possible to add data from a file, as in my own code for plotting when adding data from a file to an array.
In general, this is necessary for a program for receiving data from end devices.