一：准备文件，并将文件置于网站根目录下

    access_token.json

{"access_token":"","expire_time":0}

    jsapi_ticket.json

{"jsapi_ticket":"","expire_time":0}

    jssdk.php

 <?php

class JSSDK {

  private $appId;

  private $appSecret;

  public function __construct($appId, $appSecret) {

    $this->appId = $appId;

    $this->appSecret = $appSecret;

  }

  public function getSignPackage() {

    $jsapiTicket = $this->getJsApiTicket();

    $url = "http://$_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);

    $signPackage = array(

      "appId"     => $this->appId,

      "nonceStr"  => $nonceStr,

      "timestamp" => $timestamp,

      "url"       => $url,

      "signature" => $signature,

      "rawString" => $string

    );

    return $signPackage; 

  }

  private 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;

  }

  private 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

    $data = json_decode(file_get_contents("jsapi_ticket.json"));

    if ($data->expire_time < time()) {

      $accessToken = $this->getAccessToken();

      $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";

      $res = json_decode($this->httpGet($url));

      $ticket = $res->ticket;

      if ($ticket) {

        $data->expire_time = time() + 7000;

        $data->jsapi_ticket = $ticket;

        $fp = fopen("jsapi_ticket.json", "w");

        fwrite($fp, json_encode($data));

        fclose($fp);

      }

    } else {

      $ticket = $data->jsapi_ticket;

    }

    return $ticket;

  }

  private 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("access_token.json"));

    if ($data->expire_time < time()) {

      $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$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("access_token.json", "w");

        fwrite($fp, json_encode($data));

        fclose($fp);

      }

    } else {

      $access_token = $data->access_token;

    }

    return $access_token;

  }

  private 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;

  }

}

二：编辑显示页面对应的后台PHP文件，添加如下代码

      include('jssdk.php');

      $jssdk = new JSSDK("APPID", "APPSECRET");

      $signPackage = $jssdk->GetSignPackage(); 

      $this->signPackage = $signPackage;

请将APPID和APPSECRET换成您自己微信账号的信息

三：编辑显示页面模板html文件，添加如下代码

<script src="http://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script>

<script>

wx.config({

    appId: '{suetech:$signPackage.appId}',

    timestamp: {suetech:$signPackage.timestamp},

    nonceStr: '{suetech:$signPackage.nonceStr}',

    signature: '{suetech:$signPackage.signature}',

   jsApiList: [

        'checkJsApi',

        'onMenuShareTimeline',

        'onMenuShareAppMessage',

        'onMenuShareQQ',

        'onMenuShareWeibo'

      ]

  });

  /*

 * 注意：

 * 1. 所有的JS接口只能在公众号绑定的域名下调用，公众号开发者需要先登录微信公众平台进入“公众号设置”的“功能设置”里填写“JS接口安全域名”。

 * 2. 如果发现在 Android 不能分享自定义内容，请到官网下载最新的包覆盖安装，Android 自定义分享接口需升级至 6.0.2.58 版本及以上。

 * 3. 完整 JS-SDK 文档地址：http://mp.weixin.qq.com/wiki/7/aaa137b55fb2e0456bf8dd9148dd613f.html

 *

 * 如有问题请通过以下渠道反馈：

 * 邮箱地址：weixin-open@qq.com

 * 邮件主题：【微信JS-SDK反馈】具体问题

 * 邮件内容说明：用简明的语言描述问题所在，并交代清楚遇到该问题的场景，可附上截屏图片，微信团队会尽快处理你的反馈。

 */

wx.ready(function () {

  // 1 判断当前版本是否支持指定 JS 接口，支持批量判断

    wx.checkJsApi({

      jsApiList: [

        'getNetworkType',

        'previewImage',

         'onMenuShareTimeline',

        'onMenuShareAppMessage',

        'onMenuShareQQ',

        'onMenuShareWeibo'

      ],

      success: function (res) {

        alert(JSON.stringify(res));

      }

    });

  var shareData = {

    title: '标题',

      desc: '描述',

      link: '链接',

      imgUrl: '图片',

      trigger: function (res) {

        alert('用户点击发送给朋友');

      },

      success: function (res) {

        alert('已分享');

      },

      cancel: function (res) {

        alert('已取消');

      },

      fail: function (res) {

        alert(JSON.stringify(res));

      }

  };

  wx.onMenuShareAppMessage(shareData);

  wx.onMenuShareTimeline(shareData);

  wx.onMenuShareQQ(shareData);

  wx.onMenuShareWeibo(shareData);

});

wx.error(function (res) {

  alert(res.errMsg);

}); 

</script>

到此已经能够正常进行微信自定义分享了

需要注意的地方是在微信公众账号中配置您的域名，设置方法：

登陆微信公众账号->公众号设置->功能设置->JS接口安全域名->设置