In parent component, writes

// in import package parts
import EventEmitter from 'EventEmitter';

//in your Component class
componentWillMount = () => {
  this.eventEmitter = new EventEmitter();
}

handleAction = () => {
  this.eventEmitter.emit('SomeEvent', { someArg: 'argValue' });
}

Then pass on this.eventEmitter as props to child component.

<ChildComponent event={this.eventEmitter} />

Finally add a listener for handling events in child component.

import Subscribable from 'Subscribable';

var ChildComponent = React.createClass({
  mixins: [Subscribable.Mixin],
  componentDidMount() {
    this.addListenerOn(this.props.events, 'SomeEvent', this.myEventHandler);
  },
  //some other code goes here
});

Note that ES6 style classes do not support mixins, so you must write your child component class in legacy createClass style.

via http://stackoverflow.com/questions/31177366/react-native-call-function-of-child-from-navigatorios