通过百度地图接口，详细地址获取经纬度，并根据ip地址定位算出目标物的距离

//先全部转成经纬度，然后计算距离
private function userDistance($list)
{
    $user_ip = CommonClass::getRealIp();//获取客户端IP
    if ($user_ip != '127.0.0.1') {
        $user_ip = CommonClass:: get_lat_and_lng_ByIP($user_ip);
        foreach ($list as $k => $v) {
            $list[$k]['distance'] = number_format((CommonClass::getDistance($user_ip['lat'], $user_ip['lng'], $v['lat'], $v['lng'])) / 1000, 1);
            $list[$k]['distance'] = str_replace(',', '', $list[$k]['distance']);
        }
    }
    return $list;
}

//根据地址获取经纬度
private function address($data)
{
    foreach ($data as $k => $v) {
        if (empty($v['province_name']) || empty($v['city_name'])) {
            $data[$k]['lat'] = '';
            $data[$k]['lng'] = '';
        } else {
            $address = CommonClass:: addresstolatlag($v['province_name'] . $v['city_name'] . $v['area_name'] . $v['address']);
            $data[$k]['lat'] = $address['lat'];
            $data[$k]['lng'] = $address['lng'];
        }
    }
    return $data;
}

//根据IP获取经纬度
static function get_lat_and_lng_ByIP($ip)
{

    if (empty($ip)) {
        return 'IP不能为空';
    }
    $content = file_get_contents("http://api.map.baidu.com/location/ip?ak=y5p0BQ0IeG5IeWdOcyXGMEizLT86jUVK&services=&t=20170717103214&ip={$ip}&coor=bd09ll");
    $json = json_decode($content, true);
    $lng = $json['content']['point']['x'];//提取经度数据

    $lat = $json['content']['point']['y'];//提取纬度数据
    $arr = ['lng' => $lng, 'lat' => $lat];
    return $arr;
}

//根据地址获取经纬度
static function addresstolatlag($address)
{

    $newdata = urlencode($address);
    $url = "http://api.map.baidu.com/geocoder/v2/?address={$newdata}&output=json&ak=Ikk6ShdO60DGbRhbOCSm4rpmhWwqoQxi";
    $address_data = file_get_contents($url);
    $json_data = json_decode($address_data);
    $lng = $json_data->result->location->lng;
    $lat = $json_data->result->location->lat;
    $arr = ['lng' => $lng, 'lat' => $lat];;
    return $arr;

}
纯用php计算距离和经纬度，不用集成地图在数据库存经纬度的好处，但是如果提供给app数据，还是要存经纬度
之前发现 同市根据ip定位算距离都为0，但是自从百度api账号升级成开发者账号之后，距离突然出现，估计是百度地图升级或者是开发者账号的特殊权益定位更精确