PHP と UniApp を使用して検証コードを生成および検証する方法

<?php
session_start();

$code = '';
for ($i = 0; $i < 4; $i++) {
    $code .= chr(rand(97, 122));
}

$_SESSION['captcha'] = $code;

$image = imagecreatetruecolor(100, 30);
$bgcolor = imagecolorallocate($image, 255, 255, 255);
imagefill($image, 0, 0, $bgcolor);
$textcolor = imagecolorallocate($image, 0, 0, 0);
imagestring($image, 5, 30, 8, $code, $textcolor);

header('Content-type: image/png');
imagepng($image);
imagedestroy($image);
?>

<template>
  <view>
    <image src="{{captchaUrl}}" mode="widthFix" bindtap="refreshCaptcha"></image>
    <input type="text" v-model="verifyCode" placeholder="请输入验证码"></input>
    <button bindtap="checkVerifyCode">提交</button>
  </view>
</template>

<script>
import uniVerifycode from 'uni-verifycode';

export default {
  data() {
    return {
      captchaUrl: '',
      verifyCode: ''
    };
  },
  methods: {
    refreshCaptcha() {
      this.captchaUrl = uniVerifycode.getCaptchaUrl();
    },
    checkVerifyCode() {
      uniVerifycode.checkVerifyCode(this.verifyCode, (res) => {
        if (res) {
          uni.showToast({
            title: '验证码正确',
            icon: 'success'
          });
          // 验证码正确后的操作
        } else {
          uni.showToast({
            title: '验证码错误',
            icon: 'none'
          });
          // 验证码错误后的操作
        }
      });
    }
  },
  mounted() {
    this.refreshCaptcha();
  }
};
</script>