回答

首先登录公众号后台设置接口权限，在网页账号里点击修改

授权毁掉页面域名设置为h5网页的访问地址

具体的代码如下：

<!-- 注册页面 -->
<template>
	<view class="bottom-side-otherLogin" @click="getWeChatCode" v-if="isWeixin">
		<text>微信一键登录</text>
		
	</view>
</template>
<script>
	export default {
		data() {
			return {
				isWeixin: false,
			};
		},
		onLoad() {
			this.isWeixin = this.isWechat()
			if(this.isWeixin){
				this.checkWeChatCode()//通过微信官方接口获取code之后，会重新刷新设置的回调地址【redirect_uri】
			}
		},
		onShow() {
		},
		mounted() {
 
		},
		methods: {
			/*微信登录相关  start*/
			//方法：用来判断是否是微信内置的浏览器
			isWechat() {
			        return String(navigator.userAgent.toLowerCase().match(/MicroMessenger/i)) === "micromessenger";
			},
			//方法:用来提取code
			getUrlCode(name) {
				return decodeURIComponent((new RegExp('[?|&]' + name + '=' + '([^&;]+?)(&|#|;|$)').exec(location.href) || [, ''])[1]
					.replace(/\+/g, '%20')) || null
			},
			//检查浏览器地址栏中微信接口返回的code
			checkWeChatCode() {
				let code = this.getUrlCode('code')
				uni.showToast({
					title:`微信code=${code}`
				})
				if (code) {
					
					this.getOpenidAndUserinfo(code)
				}
			},
			//请求微信接口，用来获取code
			getWeChatCode() {
				let local = encodeURIComponent(window.location.href); //获取当前页面地址作为回调地址
				let appid = '自己的appid'
				
				//通过微信官方接口获取code之后，会重新刷新设置的回调地址【redirect_uri】
				window.location.href =
					"https://open.weixin.qq.com/connect/oauth2/authorize?appid=" +
					appid + 
					"&redirect_uri=" +
					local +
					"&response_type=code&scope=snsapi_userinfo&state=1#wechat_redirect";
			},
			//把code传递给后台接口，静默登录
			getOpenidAndUserinfo(code) {
				this.$http({
					url:'后端地址url',
					data:{
						code:code
					}
				}).then((res) => {
					console.log(res)
					if (res.code != 0) {
						uni.showToast({
							title: res.msg,
							duration: 3000,
							icon: 'none'
						});
						return
					}else{
						this.afterLogin(res)
					}
				})
			},
			/*微信登录相关  end*/
			afterLogin(res){
				let user = res.data.user
				uni.setStorageSync('token', res.data.token);
				let u = {
					avatar: user.avatar ? user.avatar : this.avatar,
					mobile: user.mobile,
					nickname: user.nickname ? user.nickname : '匿名'
				}
				uni.setStorage({
					key: 'u',
					data: u,
					success: () => {
						
						let url = uni.getStorageSync('redirect')
						uni.reLaunch({
							url: url ? url : '/pages/index'
						})
					}
				});
			},
		},
 
	}
</script>
 

<?php
$appid = "wxa423432423432423423";
$appsecret = "234234345345345345345";
function http_curl($url) {
$curlobj = curl_init();
curl_setopt($curlobj, CURLOPT_URL, $url);
curl_setopt($curlobj, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curlobj, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($curlobj, CURLOPT_SSL_VERIFYHOST, FALSE);
$output = curl_exec($curlobj);
curl_close($curlobj);
return $output;
}


$url = 'https://api.weixin.qq.com/sns/oauth2/access_token?appid='.$appid.'&secret='.$appsecret.'&code='.$_GET['code'].'&grant_type=authorization_code';
$result = $this->http_curl($url);
$acessdata = json_decode($result, 1);

if (isset($acessdata['access_token'])) {
$access_token = $acessdata['access_token'];
$openid = $acessdata['openid'];
$url2 = 'https://api.weixin.qq.com/sns/userinfo?access_token='.$access_token.'&openid='.$openid.'&lang=zh_CN';
$result2 = $this->http_curl($url2);
$userinfo = json_decode($result2, 1);
echo json_encode(['err' => false,
"data" => $userinfo]);
} else {
echo json_encode(['err' => false,
"data" => "出错了"]);
}