Como hacer en Binding de metodos en React. CodeSanbox: https://codesandbox.io/embed/5wo9q2yn9p

component.js

import React, { Component } from "react";

class MyComponent extends Component {
  constructor(props) {
    super(props);

    this.state = {
      gretting: "Hi"
    };
    this.handleButtonClick = this.handleButtonClick.bind(this);
    this.handleButtonCLickWithParam = message => this._handleButtonCLickWithParam.bind(this, message);
  }

  /**
   * This its a good binding
   */
  handleButtonClick() {
    alert(`Correct Binding: ${this.state.gretting}`);
  }

  /**
   * This its a good binding with params
   */
  _handleButtonCLickWithParam(message) {
    alert(`${this.state.gretting}: ${message}`);
  }

  /**
   * This its a bad binding, in this case, this its undefines
   */
  handleButtonClickWithoutBinding() {
    alert(`Without binding: ${this}`);
  }

  render() {
    return (
      <div className="my-component">
        <button onClick={this.handleButtonClick}>Good Binding</button>
        <button onClick={this.handleButtonCLickWithParam("world")}>
          Biding with params
        </button>
        <button onClick={this.handleButtonClickWithoutBinding}>
          Without binding!
        </button>
      </div>
    );
  }
}

export default MyComponent;