要制作微信接口分享功能，前期需要注册一个公众号，并认证通过，只有这样才能实现接口制作。在这里微信注册再不做详细的说明，大家可以直接在微信公众平台官网自己查找：mp.weixin.qq.com

下面我一步步给大家做介绍

1、公众号开发信息配置

在开发分享接口之前需要先配置公众平台配置信息，如下图所示：点击“开发-基本信息”，可以看到公众号开发信息，在开发者秘钥哪里点击“开启”，配置自己的秘钥信息，配置成功后，保存开发者ID(AppID)和开发者密码(AppSecret)

2、配置JS接口安全域名

点击“设置与开发--公众号设置”，点击JS接口安全域名后面的设置，按照要求添加js安全域名，如图所示

3、PHP分享接口类

这里不多说，直接上代码

class wechatClass
{
    public $AppID;
    public $AppSecret;
    public $redirect_uri;
    public $DbSy;
    public $dump_url;
    public $scope;
    public function __construct()
    {
        parent::__construct();
        $this->AppID = "开发者密码(AppSecret)";
        $this->AppSecret = "开发者密码(AppSecret)";
    }
    public function getSignPackage() {
        $jsapiTicket = $this->getJsApiTicket();
        // 注意 URL 一定要动态获取，不能 hardcode.
        $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
        $url = "{$protocol}{$_SERVER['HTTP_HOST']}{$_SERVER['REQUEST_URI']}";
        $timestamp = time();
        $nonceStr = $this->createNonceStr();
        // 这里参数的顺序要按照 key 值 ASCII 码升序排序
        $string = "jsapi_ticket={$jsapiTicket}&noncestr={$nonceStr}&timestamp={$timestamp}&url={$url}";
        $signature = sha1($string);
        // var_dump($signature);die;
        $signPackage = array(
            "appId"     => $this->AppID,
            "nonceStr"  => $nonceStr,
            "timestamp" => $timestamp,
            "url"       => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }
    public function createNonceStr($length = 16) {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }
    public function getJsApiTicket() {
        // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
        //echo $_SERVER['DOCUMENT_ROOT'];
        $data = json_decode(file_get_contents($_SERVER['DOCUMENT_ROOT']."/static/yejuzhi/js/access_token.json"));
        // var_dump($data->expire_time);die;
        if ($data->expire_time < time()) {
            $accessToken = $this->getAccessToken();
            // 如果是企业号用以下 URL 获取 ticket
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token=$accessToken";
            $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token={$accessToken}";
            $res = json_decode($this->httpGet($url));
            $ticket = $res->ticket;
            if ($ticket) {
                $data->expire_time = time() + 7000;
                $data->jsapi_ticket = $ticket;
                $fp = fopen($_SERVER['DOCUMENT_ROOT']."/static/yejuzhi/js/access_token.json", "w");
                fwrite($fp, json_encode($data));
                fclose($fp);
            }
        } else {
            $ticket = $data->jsapi_ticket;
        }
        return $ticket;
    }
    public function getAccessToken() {
        // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        $data = json_decode(file_get_contents($_SERVER['DOCUMENT_ROOT']."/static/yejuzhi/js/access_token.json"));
        if ($data->expire_time < time()) {
            // 如果是企业号用以下URL获取access_token
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={$this->AppID}&secret={$this->AppSecret}";
            $res = json_decode($this->httpGet($url));
            $access_token = $res->access_token;
            if ($access_token) {
                $data->expire_time = time() + 7000;
                $data->access_token = $access_token;
                $fp = fopen($_SERVER['DOCUMENT_ROOT']."/static/yejuzhi/js/access_token.json", "w");
                fwrite($fp, json_encode($data));
                fclose($fp);
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }
    public function httpGet($url){
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_URL, $url);
        $res = curl_exec($curl);
        curl_close($curl);
        return $res;
    }
}

4、PHP文件配置

这里我是以TP5.1框架写的，大家可以自行设置

$wx = new WeChatClass();
$sign = $wx->getSignPackage();
$this->assign('sign',$sign);

5、前端HTML代码

前端HTML代码请参考开发文档：https://developers.weixin.qq.com/doc/offiaccount/OA_Web_Apps/JS-SDK.html

这里我以自定义“分享给朋友”及“分享到QQ”按钮的分享内容（1.4.0）接口为例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>微信分享接口制作</title>
</head>
<body>
<script src="http://res2.wx.qq.com/open/js/jweixin-1.6.0.js"></script>
<script>
 wx.config({
        debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
 appId: '{$sign.appId}', // 必填，公众号的唯一标识
 timestamp: '{$sign.timestamp}', // 必填，生成签名的时间戳
 nonceStr: '{$sign.nonceStr}', // 必填，生成签名的随机串
 signature: '{$sign.signature}',// 必填，签名
 jsApiList: [
            "updateAppMessageShareData",] // 必填，需要使用的JS接口列表
 });
 wx.ready(function () {
        wx.updateAppMessageShareData({
            title: '您的标题', // 分享标题
 desc: '您的描述', // 分享描述
 link: '您的分享链接', // 分享链接，该链接域名或路径必须与当前页面对应的公众号JS安全域名一致
 imgUrl: '您的分享图标', // 分享图标
 success: function () {
                /*alert('成功');*/
 }
        });
 });
</script>
</body>
</html>