### 参数
无参数
### 返回值
无返回值
### 示例
```php
use Workerman\Worker;
use Workerman\Timer;
use Workerman\Connectionnew Worker('udp://0.0.0.0:1234');
$worker->onWorkerStart = function(){
// 1秒后启动一个udp客户端,连接1234端口并发送字符串udp_connection->onMessage = function(AsyncUdpConnection $udp_connection, $data){
// 收到服务端返回的数据};
$worker->onMessage = function(UdpConnection $connection, $data)
{
// 收到AsyncUdpConnection客户端发来的数据