我在两个应用程序之间设置了一个简单的 UDP 客户端/服务器数据报：Android-Java-Client 和 Windows-C#-Server。这是我第一次使用 Java 编程和 Android 应用程序，因此解决方案可能是显而易见的。这样我就成功地从客户端向服务器发送了一个数据包。但是，我无法从服务器发送回客户端。
我正在尝试将确认消息从服务器发送回客户端。我尝试将 C# 客户端代码与现有 C# 服务器代码合并，但一旦服务器收到第一条消息，它就会崩溃System.ObjectDisposedException。我删除并重新开始“如果需要，请查看已编辑的内容”。现在，我成功发送到服务器，但没有收到任何内容，Java 客户端也没有显示任何内容。我知道我可以（或者也许应该）使用相同的套接字发送回客户端。我的错误在哪里？请并谢谢。
- 我尝试把整个
NetworkThread in the OnTouchListener
- 我尝试着崩溃
SendUdpMessage()一分为二，一发送，一接收
- 我尝试了下面的答案
我仍然无法让它工作:(
C# 服务器端：
// This class is responsible of running the server side on the PC.
class UdpServer
{
static void Main(string[] args)
{
byte[] data = new byte[1024];
UdpClient serverSocket = new UdpClient(15000);
int i = 0;
while (true)
{
Console.WriteLine("Waiting for a UDP client...");
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
data = serverSocket.Receive(ref sender);
string stringData = Encoding.ASCII.GetString(data, 0, data.Length);
Console.WriteLine("Response from " + sender.Address);
Console.WriteLine("Message " + i++ + ": " + stringData + "\n");
// Here I am sending back
byte[] data2 = Encoding.ASCII.GetBytes("Response");
serverSocket.Send(data2, 8, sender);
}
}
}
Java 客户端：
按钮调用函数来发送 UDP 消息，并将响应分配到全局变量中，然后我尝试通过文本框在屏幕上显示该变量
public class MainActivity extends AppCompatActivity {
String message;
String Response;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Button Declaration
final TextView TextOne = (TextView) findViewById(R.id.StatusText);
Button LftBtn = (Button) findViewById(R.id.LeftButton);
// ...
// other code here (button declaration and event handlers
// ...
// Left Button Click
LftBtn.setOnTouchListener(
new Button.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
//Button pressed
TextOne.setText("Left");
message = "Left";
SendUdpMsg(message);
TextOne.setText(Response);
return true;
} else if (event.getAction() == MotionEvent.ACTION_UP) {
//Button released do nothing
return true;
}
return false;
}//onTouch
});//setOnTouchListener
}
// This function is responsible for sending a udp packet to a hardCoded IP below. Returns nothing and takes a string(the message) as a parameter.
public void SendUdpMsg(final String msg)
{
Thread networkThread = new Thread() {
// No local Host 127.0.0.1 in Android
String host = "192.168.200.3"; // my actual IP
int port = 15000;
DatagramSocket dsocket = null;
String Response = "1";
public void run() {
try {
// Get the Internet address of the specified host
InetAddress address = InetAddress.getByName(host);
// wrap a packet
DatagramPacket packet = new DatagramPacket(
msg.getBytes(),
msg.length(),
address, port);
// Create a datagram socket, send the packet through it, close it.
dsocket = new DatagramSocket();
dsocket.send(packet);
// Here, I am receiving the response?
byte[] buffer = new byte[1024];
DatagramPacket packet2 = new DatagramPacket(buffer, buffer.length);
dsocket.receive(packet2);
Response = new String(buffer, 0, packet2.getLength());
runOnUiThread(new Runnable() {
@Override
public void run()
{
// I can't use this since TextOne is a local variable in the above function
//TextOne.setText(Response);
}
});
dsocket.close();
} catch (Exception e) {
e.printStackTrace();
}//catch
}//run
};// Networkthread
networkThread.start();//networkThread.start()
}
}
