微信JSAPI支付实现

1.获取到mch_id ,appid,appsecrect,api秘钥
2.下载安装证书
3.在商户中心配置jsapi目录，发起起调的页面。
4.公众号配置回调域名，业务，js域名。
5.加入安全白名单。

不多说了上代码前端

<script>function wxpay(){var money = $('#paymoney').text();var o_sonid=$('#o_sonid').attr('data-id');var o_sonid=parseInt(o_sonid);var money =parseFloat(money);var id = $('.this').find('.index_id').val();    if(money){        $.ajax({            url:"{:U('Orders/wxpay')}",            data:{                money:money,                id:o_sonid,            },            dataType:"json",            type:"POST",            success:function(data){                WeixinJSBridge.invoke('getBrandWCPayRequest',data,function(res){                            if(res.err_msg == 'get_brand_wcpay_request:ok'){                            window.location.reload();                            }                        });            }        })    }else{        alert('请确定金额！');    }}</script>

后端代码

  function wxpay(){    $money=I('post.money');    $id=I('post.id');   //对应订单子订单    $order_goods=M('order_goods');    $orderinfo=$order_goods->where('id='.$id)->find();    $out_trade_no= $orderinfo['create_time'].mt_rand(0000,9999);    $order_goods->where('id='.$id)->setField('out_trade_no',$out_trade_no);    // $data= M('order')->where('order_id='.$_POST['id'])->find();    $url = 'https://api.mch.weixin.qq.com/pay/unifiedorder';    $arr = array(      'appid' => $this->appid,      'mch_id' => $this->mch_id,      'nonce_str' => $this->getNonceStr(),      'body' =>$orderinfo['goods_name'],      'out_trade_no' => $out_trade_no,      'total_fee' => $money * 100,      // 'total_fee' => 1,      'spbill_create_ip' => $_SERVER['REMOTE_ADDR'],      'notify_url' => 'http://xxxxx.com/index.php/Home/Orders/weixin/',      'trade_type' => 'JSAPI',      'openid' => $_SESSION['openid']    );    $arr['sign'] = $this->sign($arr);    $data = $this->ToXml($arr);    $result = $this->postData($url,$data);    $options = array(      'appId' => $this->appid,      'timeStamp' => (string)time(),      'nonceStr' => $this->getNonceStr(),      'package' => 'prepay_id='.$result['prepay_id'],      'signType' => 'MD5',    );    $options['paySign'] = $this->sign($options);    die(json_encode($options));  }  //支付回调处理（不能继承基类验证页面之类的）    public function weixin(){        $postStr = $GLOBALS['HTTP_RAW_POST_DATA'];        $postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);        if($postObj->return_code == 'SUCCESS'){      //获取交易金额 ,修改订单状态。      $money = $postObj->total_fee;            $money = (iconv("gbk", "UTF-8", $money))/100;      $out_trade_no= $postObj->out_trade_no;      $out_trade_no = (iconv("gbk", "UTF-8", $out_trade_no));      $order_goods=M('order_goods');      $order_goods->pay_money=$money;      $order_goods->payment_notify_time=time();      $order_goods->pay_status='2';      $map['out_trade_no']=$out_trade_no;            $order_goods->where($map)->save();      //商品销售量+1      $o_soninfo=M('order_goods')->where('out_trade_no='.$out_trade_no)->find();      M('goods')->where('id='.$o_soninfo['goods_id'])->setInc('sale_num');    }    die('<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>');    }  //微信授权（必须先获取用户openid）    public function access_token(){          // $tid = $_REQUEST['tid'];        $code = $_REQUEST['code'];        $res = file_get_contents("https://api.weixin.qq.com/sns/oauth2/access_token?appid=你的appid&secret=你的app秘钥&code=".$code."&grant_type=authorization_code");        $list = json_decode($res);        $access_token = $list->access_token;        $openid = $list->openid;        $row = file_get_contents("https://api.weixin.qq.com/sns/userinfo?access_token=".$access_token."&openid=".$openid."&lang=zh_CN");        $arr = json_decode($row);        if ($arr->openid) {            $data['openid'] = $arr->openid;          $data['create_time'] =time();          $data['status']='1';          $data['img']=$arr->headimgurl;            // $data['tid'] = $tid;            $id = M('user')->where("openid='".$data['openid']."'")->getField('id');            if(!$id){                $id = M('user')->add($data);            }            $_SESSION['uid'] = $id;          session('uid',$id);              $_SESSION['openid'] = $data['openid'];            if($_SESSION['uid']){                $this->redirect('User/index');            }        }    }    //获取code码        public function getOpenId(){     $url = 'http://xxxxx.com/index.php/Home/Orders/access_token/';     $url = 'https://open.weixin.qq.com/connect/oauth2/authorize?appid=？&redirect_uri='.urlencode($url).'&response_type=code&scope=snsapi_userinfo&state=STATE#wechat_redirect';     header('location:'.$url);    }

ps：再说一些开发中遇到的坑
1.如果拿不到openid 果断换个服务器试试吧，不多说了都是泪~。
2.支付过程中不能用session传递参数
3.别的没啥了