eveation 是Android 平台都有的样式键，它是数值类型的样式键，通过在组件的周围渲染阴影效果，让用户产生组件浮现在手机上的效果。

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

export default class ViewProject extends Component {
  render() {
    return (
      <View style={styles.container}>
         <View style={styles.block} />
         <View style={styles.block1} />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,justifyContent:"space-around",alignItems:"center",backgroundColor:"white",},block:{
    width:150,height:150,borderWidth:1,backgroundColor:"black",borderRadius:25,block1:{
    width:150,elevation:100
  },});
AppRegistry.registerComponent('ViewProject',() => ViewProject);