微信小程序如何实现一个点击生成随机验证码功能

{{ code }}

Page({
data: {
 code: &＃39;&＃39;
},
onLoad() {
 //进入页面就调用方法 创建一个随机验证码
 this.createCode()
},

getCode() {
 //点击调用创建验证码方法
 this.createCode()
},

//创建随机验证码方法
createCode() {
 let code = &＃39;&＃39;; //初始化验证码
 let codeLength = 6; //设置验证码长度
 //设置随机字符
 let txt = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, &＃39;A&＃39;, &＃39;B&＃39;, &＃39;C&＃39;, &＃39;D&＃39;, &＃39;E&＃39;, &＃39;F&＃39;, &＃39;G&＃39;, &＃39;H&＃39;, &＃39;I&＃39;, &＃39;J&＃39;, &＃39;K&＃39;, &＃39;L&＃39;, &＃39;M&＃39;, &＃39;N&＃39;, &＃39;O&＃39;, &＃39;P&＃39;, &＃39;Q&＃39;, &＃39;R&＃39;, &＃39;S&＃39;, &＃39;T&＃39;, &＃39;U&＃39;, &＃39;V&＃39;, &＃39;W&＃39;, &＃39;X&＃39;, &＃39;Y&＃39;, &＃39;Z&＃39;);
 //循环
 for(let i = 0; i