如何在React Native中自定义T形梳形？

Question

我正在尝试自定义特定的输入字段，特别是扩大输入区域。我找到了一个示例，但它似乎并未自定义特定的 field ，而是自定义了特定类别的字段：

import React, { Component } from 'react';
import { View, StyleSheet, Button } from 'react-native';

import t from 'tcomb-form-native'; // 0.6.9

const Form = t.form.Form;

const User = t.struct({
  email: t.String,
  username: t.maybe(t.String),
  password: t.String,
  terms: t.Boolean
});

const formStyles = {
  ...Form.stylesheet,
  formGroup: {
    normal: {
      marginBottom: 10
    },
  },
  controlLabel: {
    normal: {
      color: 'blue',
      fontSize: 18,
      marginBottom: 7,
      fontWeight: '600'
    },
    // the style applied when a validation error occours
    error: {
      color: 'red',
      fontSize: 18,
      marginBottom: 7,
      fontWeight: '600'
    }
  }
}

const options = {
  fields: {
    email: {
      error: 'Without an email address how are you going to reset your password when you forget it?'
    },
    password: {
      error: 'Choose something you use on a dozen other sites or something you won\'t remember'
    },
    terms: {
      label: 'Agree to Terms',
    },
  },
  stylesheet: formStyles,
};

有人知道我如何自定义说“仅电子邮件”字段吗？