php

<?php
declare (strict_types = 1);
namespace app\api\controller;
class WxJsSdk
{


    public $appid; //公众号appi
    public $appsecret; //公众号密钥
    public $merid; //商户号
    public $merkey; //商户支付密钥
   
    //读取配置数据
    function __construct(){
        $this->appid = env('WX.appid');
        $this->appsecret = env('WX.appsecret');
        $this->merid = env('WX.merid');
        $this->merkey = env('WX.merkey');
    }

    //获取wx.config需要的参数
    public function getWxConfig(){
        $link = input('link');
        $access_token = $this->get_token($this->appid,$this->appsecret,1,1);

       
        $jsapiTicket = $this->get_ticket($access_token);

        $nonceStr = $this->nonceStr(16);
        $timestamp = time();
       
        $string = 'jsapi_ticket='.$jsapiTicket.'&noncestr='.$nonceStr.'&timestamp='.$timestamp.'&url='.$link;
        $signature = sha1 ($string);
        $WxConfig["appid"] = $this->appid;
        $WxConfig["noncestr"] = $nonceStr;
        $WxConfig["timestamp"] = $timestamp;
        $WxConfig["signature"] = $signature;
        $WxConfig["debug"] = true;
        return $WxConfig;
    }
   
    //生成签名的随机串
    public function nonceStr($length){
        $str = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJK1NGJBQRSTUVWXYZ';//随即串，62个字符
        $strlen = 62;
        while($length > $strlen){
            $str .= $str;
            $strlen += 62;
        }
        $str = str_shuffle($str);
        return substr($str,0,$length);
    }
   
    //获取access_token
    public function get_token($appid,$appsecret,$debug=0,$noCacheToken=1){
        if(!isset($_COOKIE['token']) || $debug == 1 || $noCacheToken == 1){
            $result = $this->http_get('https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid='.$appid.'&secret='.$appsecret);
            $result = json_decode($result,true);
            $access_token = $result['access_token'];
            setcookie('token',$access_token,time()+7199);
        }else{
             $access_token = $_COOKIE['token'];
        }
        return $access_token;
    }
   
   
    //获取ticket
    public function get_ticket($access_token){
        $url = 'https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token='.$access_token;
        $res = json_decode($this->http_get($url));
        $ticket = $res->ticket;
        return $ticket;
    }
   
    //请求方法
    public function http_get($url){
        $oCurl = curl_init();
        if(stripos($url,"https://")!==FALSE){
            curl_setopt($oCurl, CURLOPT_SSL_VERIFYPEER, FALSE);
            curl_setopt($oCurl, CURLOPT_SSL_VERIFYHOST, FALSE);
            curl_setopt($oCurl, CURLOPT_SSLVERSION, 1); //CURL_SSLVERSION_TLSv1
        }
        curl_setopt($oCurl, CURLOPT_URL, $url);
        curl_setopt($oCurl, CURLOPT_RETURNTRANSFER, 1 );
        $sContent = curl_exec($oCurl);
        $aStatus = curl_getinfo($oCurl);
        curl_close($oCurl);
        if(intval($aStatus["http_code"])==200){
            return $sContent;
        }else{
            return false;
        }
    }
}



?>

js

async getWxConfig(item){
	const res =  await req('WxjsSdk/getWxConfig',{link:window.location.href});
	wx.config({
		debug: 1,
		appId: res.appid, 
		timestamp: res.timestamp, 
		nonceStr: res.noncestr, 
		signature: res.signature, 
		jsApiList: ["chooseImage","previewFile"]
	});

	wx.ready(() => {

		//判断接口方法是否可用
		wx.checkJsApi({
			jsApiList: ['chooseImage','previewFile'], // 需要检测的JS接口列表，所有JS接口列表见附录2,
			success: function(res) {
				console.log(res);
			}
		});

		//alert('准备好了');
	});

}