静态页面实现微信分享带缩略图、标题和描述-爱资源分享网

在前一篇文章《微信转发或分享朋友圈带缩略图、标题和描述的实现方法》中，余斗已经教大家如何实现在自有网站上实现微信分享后自带缩略图、标题和描述，这里是在动态php页面中实现，这里有很大的局限性，想要在静态页面中实现这个功能则需要进一步开发，这里就要用到大ajax技术，在这里分享给大家。

服务端文件jssdk.php代码：

<?php
$url = $_GET['url'];
class JSSDK {
private $appId;
private $appSecret;
private $url;
public function __construct($appId, $appSecret,$url) {
$this->appId = $appId;
$this->appSecret = $appSecret;
$this->url = $url;
}

public function getSignPackage() {
$jsapiTicket = $this->getJsApiTicket();
$protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
// $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
$url =$this->url;
$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"; //这里经常出问题,一般都是这里出现问题，要留意

$signature = sha1($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();
// 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;
$fp = fopen("jsapi_ticket.json", "w");
fwrite($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()) {
// 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;
$fp = fopen("access_token.json", "w");
fwrite($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;
}
}

$jssdk = new JSSDK("APPID", "APPSECRET",$url);//按照自己的公众号填写
$signPackage = $jssdk->GetSignPackage();
// var_dump($signPackage);
$tmp=json_encode(array ('appId'=>$signPackage["appId"],'timestamp'=>$signPackage["timestamp"],'nonceStr'=>$signPackage["nonceStr"],'signature'=>$signPackage["signature"],'url'=>$signPackage["url"]));
$callback = $_GET['callback'];
echo $callback.'('.$tmp.')';
exit;
?>

静态页面js代码：

配置好jssdk.php文件后，只需要把js代码加入到静态页面模版中即可。

还有一个地方需要注意的是还有script获取的地址一定是要转码过的，不带#的，下面这段话是微信官方给的

确保你获取用来签名的url是动态获取的，动态页面可参见实例代码中php的实现方式。如果是html的静态页面在前端通过ajax将url传到后台签名，前端需要用js获取当前页面除去'#'hash部分的链接（可用location.href.split('#')[0]获取,而且需要encodeURIComponent），因为页面一旦分享，微信客户端会在你的链接末尾加入其它参数，如果不是动态获取当前链接，将导致分享后的页面签名失败。

以上文件下载

微信分享链接出现 errMsg: ＂config:invalid signature＂错误的解决方法

2018.5.21更新：引入js文件更新