本文实例讲述了微信小程序webview实现长按点击识别二维码功能。分享给大家供大家参考，
本文实例讲述了微信小程序webview实现长按点击识别二维码功能。分享给大家供大家参考，具体如下：
场景：微信小程序，使用webview控件。需求：点击图片后长按图片出现“识别二维码”
1、JS代码：
<script src="http://res.wx.qq.com/open/js/jweixin-1.2.0.js"></script>
<script type="text/javascript">
$(function(){
var returnData = false;
$.ajax({
type : "get",
url : 'http://app.ka.com/m/config.php',
data : [],
async : false,
success: function(data,textStatus,jqXHR){
returnData = data;
//console.log(returnData);
}
});//end ajax
var returnData = eval('(' + returnData + ')');
console.log(returnData);
var appId = returnData.appId;
var timestamp = returnData.timestamp;
var nonceStr = returnData.nonceStr;
var signature = returnData.signature;
wx.config({
debug: true, //调试阶段建议开启
appId: appId,
timestamp: timestamp,
nonceStr: nonceStr,
signature: signature,
jsApiList: [
/*
* 所有要调用的 API 都要加到这个列表中
* 这里以图像接口为例
*/
"chooseImage",
"previewImage",
"uploadImage",
"downloadImage",
"scanQRCode"
]
});
wx.ready(function() {
//alert(3);
wx.checkJsApi({
jsApiList : ['scanQRCode','previewImage'],
success : function(res) {
}
});
$("img").click(function(){
var url = "http://app.ka.com/"+$(this).attr("src");
wx.previewImage({
current: url, // 当前显示图片的http链接
urls: [url] // 需要预览的图片http链接列表
});
});
});
wx.error(function(res){
// config信息验证失败会执行error函数，如签名过期导致验证失败，具体错误信息可以打开config的debug模式查看，也可以在返回的res参数中查看，对于SPA可以在这里更新签名。
console.log(res);
});
});
</script>
2、服务端代码（获取config配置信息）：
<?php
date_default_timezone_set("Asia/Shanghai");
$jssdk = new Jssdk();
$signPackage = $jssdk->getSignPackage();
echo json_encode($signPackage);exit;
class Jssdk
{
private $_CI;
private $appId;
private $appSecret;
public function __construct($appId='wx666666', $appSecret='ee32') {
$this->appId = $appId;
$this->appSecret = $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=$nonceStr×tamp=$timestamp&url=$url";
$signature = sha1($string);
$signPackage = array(
"appId" => $this->appId,
"nonceStr" => $nonceStr,
"timestamp" => $timestamp,
"url" => $url,
"signature" => $signature,
"rawString" => $string,
'jsapiTicket' =>$jsapiTicket,
);
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 = $this->get_php_file("jsapi_ticket");
//echo $data['expire_time'].'------'.time();
//print_r($data);exit;
if (!isset($data['jsapi_ticket']) || (isset($data['expire_time']) && $data['expire_time'] < time())) {
//echo 1111;
$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";
//echo $url;
$res = json_decode($this->httpGet($url), true);
$ticket = isset($res['ticket']) ? $res['ticket'] : false;
if ($ticket) {
$data['expire_time'] = time() + 7160;
$data['token_value'] = $ticket;
$this->set_php_file("jsapi_ticket", $data);
}
} else {
//echo 22222;
$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 = $this->get_php_file("access_token");
if (!isset($data['access_token']) || (isset($data['expire_time']) && $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($url));
//var_dump($res);exit;
$access_token = $res->access_token;
if ($access_token) {
$data['expire_time'] = time() + 7160;
$data['token_value'] = $access_token;
$this->set_php_file("access_token", $data);
}
} else {
$access_token = $data['access_token'];
}
return $access_token;
}
private function httpGet($url) {
$curl = curl_init();
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_TIMEOUT, 500);
// 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
// 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($curl, CURLOPT_URL, $url);
$res = curl_exec($curl);
curl_close($curl);
return $res;
}
private function get_php_file($token_name) {
if(file_exists($token_name)) return false;
return json_decode(file_get_contents($token_name), true);
}
private function set_php_file($token_name, $data) {
$fp = fopen($token_name, "w");
fwrite($fp, "<?php exit();?>" . json_encode($data));
fclose($fp);
}
}
这里再为大家推荐一款功能相似的在线工具供大家参考：
在线二维码解码识别工具： http://tools.jb51.net/transcoding/trans_qrcode
希望本文所述对大家微信小程序开发有所帮助。
微信小程序 webview 长按 点击 识别 二维码