title: How to retrieve form values from a React.FormEvent<HTMLFormElement>?
body: <p>I want to retrieve the values from a <code>&lt;form&gt;</code> element when a user submits the form. I  do not want to use <code>onChange</code> listener and setting the values in the state. How can I accomplish this?</p>
  
  <p><strong>login.tsx</strong></p>
  
  <pre><code>...
  
  interface LoginProps {
      authService: Auth
  }
  
  export default class Login extends React.Component&lt;LoginProps, {}&gt; {
  
      constructor(props: LoginProps, context: any) {
          super(props, context);
  
          this.onSubmit = this.onSubmit.bind(this);
      }
  
      private onSubmit(e: React.FormEvent&lt;HTMLFormElement&gt;) {
          e.preventDefault();
  
          // how can I retrieve the username and password value from the FormEvent
  
          this.props.authService.authenticate(username, password)
      }
  
      render(): React.ReactNode {
          return (
              &lt;div className="container"&gt;
                  &lt;div className="col align-self-center"&gt;
                      &lt;form className="form-signin" onSubmit={this.onSubmit}&gt;
                          &lt;img className="mb-4" src={Logo} height={72}/&gt;
                          &lt;label htmlFor="input_username"&gt;Gebruikersnaam&lt;/label&gt;
                          &lt;input type="text" id="input_username" className="form-control" required={true}
                                 autoFocus={true} tabIndex={1}/&gt;
                          &lt;label htmlFor="input_password"&gt;Password&lt;/label&gt;
                          &lt;input type="password" id="input_password" className="form-control" required={true}
                                 tabIndex={2}/&gt;
                          &lt;button className="btn btn-lg btn-primary btn-block" type="submit" tabIndex={3}&gt;Aanmelden
                          &lt;/button&gt;
                      &lt;/form&gt;
                  &lt;/div&gt;
              &lt;/div&gt;
          );
      }
  }
  </code></pre>