Android和UDP数据包的奇怪行为

Question

I made a simple app in android studio to send UDP packets, so when I click a button it calls a function to check which type of component called that function and sends different packet's data respectively. Here is the function which sends the packet:

    public void sendPacket(View v) {
    if (v instanceof Button)
        buffer = ((Button) v).getHint().toString().getBytes();
    else if (v instanceof EditText)
        buffer = ((EditText) v).getText().toString().getBytes();
    Thread thread = new Thread(new Runnable() {
        @Override
        public void run() {
            DatagramPacket packet = new DatagramPacket(buffer, buffer.length, ip, port);
            try {
                SelectionActivity.datagramSocket.send(packet);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });
    thread.start();
}

Here is the listener in the main function which calls the sendPacket() function:

        btn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (<some checks>)
                sendPacket(txt.findViewById(R.id.txt));
            sendPacket(btn.findViewById(R.id.btn));
        }
    });

The problem is that it randomly sends one data and/or the other even if it change .

For example:

1)

buffer = 0x01

send 0x01

buffer = 0x02

send 0x02

2)

buffer = 0x01

send 0x01

buffer = 0x02

send 0x01

WTF?!

Answer 1

通过使用thread.join()解决，因为它需要在使用更新的缓冲区发送新数据包之前等待线程完成。