The ref keyword is used to pass an argument by reference, not value. The ref keyword makes the formal parameter alias for the argument, which must be a variable. In other words, any operation on the parameter is made on the argument. For example: void Method(ref int refArgument) { refArgument = refArgument + 44; } … Read more
You are not using createRef and trying to use focus method which is the issue. Simply create callback ref and you are good to go. Here is the working code below and codesandbox link. index.js import React from “react”; import ReactDOM from “react-dom”; import FocusComp from “./FocusComp”; class App extends React.Component { state = { … Read more
You can change the method like that: public class Util { public static T[] Transform<T>(T[] values, Transformer<T> t) { return values.Select(x => t(x)).ToArray(); } } Then you can call it like var result = Utils.Transform(values, Square); If you can’t change that method, then you need to copy the array before calling: var result = values.ToArray(); … Read more