[Ethernet]
描述
Get the number of bytes (characters) available for reading from the buffer. This is data that’s already arrived. This function can only be successfully called after Udp.parsePacket(). available()
inherits from the Stream utility class.
語法
// An EthernetUDP instance to let us send and receive packets over UDP EthernetUDP Udp; Udp.available()
參數
None
回傳
the number of bytes available to read
範例
#include <Ethernet.h> #include <EthernetUdp.h> // Enter an IP address for your controller below. // The IP address will be dependent on your local network: IPAddress ip(192, 168, 1, 177); unsigned int localPort = 8888; // local port to listen on // An EthernetUDP instance to let us send and receive packets over UDP EthernetUDP Udp; char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; //buffer to hold incoming packet, void setup() { // start the Ethernet and UDP: Ethernet.begin(NULL,ip); Udp.begin(localPort); } void loop() { int packetSize = Udp.parsePacket(); if(Udp.available()) { Serial.print("Received packet of size "); Serial.println(packetSize); Serial.print("From "); IPAddress remote = Udp.remoteIP(); for (int i =0; i < 4; i++) { Serial.print(remote[i], DEC); if (i < 3) { Serial.print("."); } } Serial.print(", port "); Serial.println(Udp.remotePort()); // read the packet into packetBufffer Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE); Serial.println("Contents:"); Serial.println(packetBuffer); } }
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函式庫參考主頁面
86Duino 參考的文本是根據 Creative Commons Attribution-ShareAlike 3.0 License,部分文本是從 the Arduino reference 修改的。 參考中的代碼示例已發佈到公共領域。