netconn_recv(udpconn, &recvbuf)接收不到数据

buf, len)

The netconn_recv() function is used to receive incoming data on a UDP connection. It takes three arguments:

1. udpconn: This is the UDP connection on which the data is to be received.

2. buf: This is the buffer where the received data will be stored.

3. len: This is the maximum length of data that can be received in a single call.

The function returns the number of bytes received, or a negative error code if an error occurred. If the return value is zero, it means that the connection was closed by the remote endpoint.

Note that the netconn_recv() function is a blocking call, which means that it will wait until data is available before returning. To avoid blocking indefinitely, it is recommended to use a timeout or a non-blocking mode.