ReactJS - How can I set a value for textfield from material-ui?

It's maintained that the right way is to have the component be controlled in a scenario like the accepted answer there, but you can also control the value in this gross and culturally unacceptable way.

<TextField ref='name'/>

this.refs.name.getInputNode().value = 'some value, hooray'

and you can of course retrieve the value like so

this.refs.name.getValue()

Instead of using ref you should use inputRef

const MyComponent = () => {
  let input;

  return (
    <form
      onSubmit={e => {
        e.preventDefault();
        console.log(input.value);
      }}>
      <TextField
        hintText="Enter Name" 
        floatingLabelText="Client Name" 
        autoWidth={1}
        inputRef={node => {
          input = node;
        }}/>
    </form>
  )
};

You can do it in this way

export default class MyCustomeField extends React.Component {

      constructor(props) {
        super(props);

        this.state = {
          value: 'Enter text',
        };
      }

      handleChange = (event) => {
        this.setState({
          value: event.target.value,
        });
      };

     handleClick = () => {
        this.setState({
          value:'',
        });
      };

      render() {
        return (
          <div>
            <TextField
              value={this.state.value}
              onChange={this.handleChange}
            />
            <button onClick={this.handleClick}>Reset Text</button>
          </div>
        );
      }
    }