TestForm.js

 import React, { Component } from 'react';
import { View, Image, StyleSheet, Dimensions, Animated, Text, TextInput, Button,TouchableHighlight } from 'react-native';
import t from 'tcomb-form-native';

var Form = t.form.Form;

// here we are: define your domain model
var Name = t.refinement(t.String, function (n) { return n!=null; });

var Person = t.struct({
    name: Name,              // a required string
    surname: t.maybe(t.String),  // an optional string
    age: t.Number,               // a required number
    rememberMe: t.Boolean        // a boolean
});

var options = {
    fields: {
      name: {
        error: 'Insert a valid name'
      }
    }
  };
  Name.getValidationErrorMessage = function (value, path, context) {
    //if something
    return 'bad name';
  };  
class TestForm extends Component {
    constructor(props) {
        super(props);
        this.state = {
            text: "",
           value: {
                name: 'Giulio',
               surname: 'Canti',
              age:18,
             rememberMe:false
            }
        }
    }
    onPress = () => {
        // call getValue() to get the values of the form
        var value = this.refs.form.getValue();
        if (value) { // if validation fails, value will be null
           alert(JSON.stringify(value))
        }
    }
onChange(value) {
    this.setState({value});
  },
    componentDidMount() {
      
    }
    render() {

        return (
            <View style={styles.container}>

                <Form
                    ref="form"
                    type={Person}
                    value={this.state.value}
                  //  options={options}
                   onChange={this.onChange}
                />
                <TouchableHighlight style={styles.button} onPress={this.onPress} underlayColor='#99d9f4'>
                    <Text style={styles.buttonText}>Save</Text>
                </TouchableHighlight>
            </View>


        );
    }
}
export default TestForm;


var styles = StyleSheet.create({
    container: {
        justifyContent: 'center',
        marginTop: 50,
        padding: 20,
        backgroundColor: '#ffffff',
    },
    buttonText: {
        fontSize: 18,
        color: 'white',
        alignSelf: 'center'
    },
    button: {
        height: 36,
        backgroundColor: '#48BBEC',
        borderColor: '#48BBEC',
        borderWidth: 1,
        borderRadius: 8,
        marginBottom: 10,
        alignSelf: 'stretch',
        justifyContent: 'center'
    }
});