微信小程序实现红包功能（后端PHP实现逻辑）

 //抢红包相关
 view_moneysure: function () {
  var that = this;
  wx.request({
   url: app.globalData.baseurl +'api/wxopen/applet/grab',//这个链接是后端写的 
   header: {
    'Content-Type': 'application/x-www-form-urlencoded'
   },
   data: {
    openid: app.globalData.openid,
    auth: app.globalData.pcUserInfo.auth
   },
   method: 'POST',
   success: function (response) {
    console.log(response);
    if (response.data.status==1){
     that.setData({
      paymsg: response.data.total_amount+'元\n现金红包',
      paymsg2: '恭喜您\n成功领取下单红包奖励'
     })
    }else{
     that.setData({
      paymsg: '领取失败\n'+response.data.msg,
      paymsg2: '非常抱歉\n如不不明，请联系客服'
     })
    }

   },
   fail: function (res) {
    console.log(response);
    that.setData({
     paymsg: '领取失败'
    })
   }
  })
 },
 showHb: function () {
  this.setData({
   showFlag: 1
  })
 },
 openHb: function () {
  this.setData({
   paymsg: '',
   paymsg2: ''
  })
  this.view_moneysure()
  var _self = this;
  _self.setData({
   _num: 1
  })
  setTimeout(function () {
   _self.setData({
    _num: 0,
    showFlag: 0,
    bghide: 1
   })
  }, 1000)

 },
 closeHb:function(){
  this.setData({
   bghide:0
  })
 },

<button class="btn" bindtap="showHb">领红包</button>

<view class="draw-list {{showFlag == 1? 'active':''}}">
 <image bindtap="openHb" class="{{_num==1?'active':''}}" src="http://www.17sucai.com/preview/1/2017-11-02/hb/image/open.png"></image>
</view>

<view id="receive1" class="win1 {{bghide==1?'active':''}}">
  <view class="openhb {{bghide==1?'active':''}}">
    <view class="winBody2">
      <view class="receive1-bg1">
       <view class="receive1-head">
        <text>{{paymsg}}</text>
       </view>
       <view class="receive1-body"><text>{{paymsg2}}</text></view>
       <button class="receive1-but1" bindtap="closeHb">确定</button>
       <view class="receive1-bg2"></view>
     </view>
   </view>
  </view>
</view>

/*
 * 企业付款到零钱
 **/
public function weixin_pay_person($re_openid)
{
  $obj = new WxopenWechatService();
  // 请求参数
  $data['mch_appid'] = WxopenWechatConfig::$init_config_applet['appid'];//商户号
  $data['mchid'] = WxopenWechatConfig::$compay_config['mch_id'];//商户账号appid
  $data['nonce_str'] = $this->get_unique_value();// 随机字符串
  //商户订单号，可以按要求自己组合28位的商户订单号
  $data['partner_trade_no'] = $this->get_tradeno($data['mchid']);
  $data['openid'] = $re_openid;//用户openid
  $data['check_name'] = 'NO_CHECK';//校验用户姓名选项
  $data['amount'] = '100';//金额,单位为分
  $data['desc'] = "恭喜你得到一个红包";//企业付款描述信息
  $data['spbill_create_ip'] = $obj->get_client_ip();//IP地址

  $appsecret = WxopenWechatConfig::$compay_config['key'];
  $data['sign'] = $this->sign($data, $appsecret);
  //发红包接口地址
  $url = "https://api.mch.weixin.qq.com/mmpaymkttransfers/promotion/transfers";

  //将请求数据由数组转换成xml
  $xml = $this->arraytoxml($data);
  //进行请求操作
  $res = $this->curl($xml, $url);
  //将请求结果由xml转换成数组
  $arr = $this->xmltoarray($res);

  if (is_array($arr)) {
    $arr['total_amount'] = $data['amount'];
  }
  //请请求信息和请求结果录入到数据库中
  // 输出请求结果数组
  return $arr;
}

public function create_rand_money($start = 30, $end = 100)
{
  return mt_rand($start, $end);
}

public function sign($params, $appsecret)
{
  ksort($params);
  $beSign = array_filter($params, 'strlen');
  $pairs = array();
  foreach ($beSign as $k => $v) {
    $pairs[] = "$k=$v";
  }

  $sign_data = implode('&', $pairs);
  $sign_data .= '&key=' . $appsecret;
  return strtoupper(md5($sign_data));
}

/*
 * 生成32位唯一随机字符串
 **/
private
function get_unique_value()
{
  $str = uniqid(mt_rand(), 1);
  $str = sha1($str);
  return md5($str);
}

/*
 * 将数组转换成xml
 **/
private
function arraytoxml(
  $arr
) {
  $xml = "<xml>";
  foreach ($arr as $k => $v) {
    $xml .= "<" . $k . ">" . $v . "</" . $k . ">";
  }
  $xml .= "</xml>";
  return $xml;
}

/*
 * 将xml转换成数组
 **/
private
function xmltoarray(
  $xml
) {
  //禁止引用外部xml实体
  libxml_disable_entity_loader(true);
  $xmlstring = simplexml_load_string($xml, "SimpleXMLElement", LIBXML_NOCDATA);
  $arr = json_decode(json_encode($xmlstring), true);
  return $arr;
}

/*
 * 进行curl操作
 **/
private
function curl(
  $param = "", $url
) {
  $postUrl = $url;
  $curlPost = $param;
  //初始化curl
  $ch = curl_init();
  //抓取指定网页
  curl_setopt($ch, CURLOPT_URL, $postUrl);
  //设置header
  curl_setopt($ch, CURLOPT_HEADER, 0);
  //要求结果为字符串且输出到屏幕上
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  //post提交方式
  curl_setopt($ch, CURLOPT_POST, 1);
  // 增加 HTTP Header（头）里的字段
  curl_setopt($ch, CURLOPT_POSTFIELDS, $curlPost);
  // 终止从服务端进行验证
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
  curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

  //这个是证书的位置
  curl_setopt($ch, CURLOPT_SSLCERT, __DIR__ . '/cert/apiclient_cert.pem');
  //这个也是证书的位置
  curl_setopt($ch, CURLOPT_SSLKEY, __DIR__ . '/cert/apiclient_key.pem');
  //运行curl
  $data = curl_exec($ch);
  //关闭curl
  curl_close($ch);

  return $data;

}

public function get_tradeno($str)
{
  return $str . date("Ymd", time()) . date("His", time()) . rand(1111, 9999);
}