项目需要Socket通信，手机做为客户端，这边写了一个TcpClient类。

在Activity1中实例化了TcpClient类，获取到了socket。

我要如何才能在Activity2中获得这个socket或者TcpClient实例 (需要用到TcpClient类中定义收发函数)?

Activity2

获取不到是为什么呢？是不是继承Acitivity的类里面的成员变量是在main函数里的？

Activity1

...
  public static TcpClient tcpClient = null;
....
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);
    context = this;
    bindReceiver();
    connectText = findViewById(R.id.content_text);
    button = findViewById(R.id.start_btn);
    button.setEnabled(false);
    CustomDialog.Builder builder = new CustomDialog.Builder(Welcome.this);
    builder.setMessage("请使用蓝牙或WiFi进行连接");
    builder.setPositiveButton(getDrawable(R.drawable.wifi_btn), new DialogInterface.OnClickListener() {
      public void onClick(DialogInterface dialog, int which) {
        dialog.dismiss();
        imageViewPositive = customDialog.findViewById(R.id.positiveTextView);
        //设置你的操作事项
        try {
          try{
            checkTimeOut();
            tcpClient = new TcpClient(Constants.SERVER_IP,Constants.SERVER_PORT);
            exec.execute(tcpClient);

TcpClient类

public class TcpClient implements Runnable {

final private String TAG = "TcpClient";
private String serverIP = "192.168.10.2";
private int serverPort = 8080;
private Socket socket = null;
private PrintWriter pw;
private InputStream is;
private DataInputStream dis;
private Boolean isRun = true;
byte buff[] = new byte[4096];
byte content[] = new byte[160];
private String rcvMsg;
private int rcvLen;
private String rcvMsgg;
private DataOutputStream dop;

public TcpClient(String serverIP, int serverPort) {
this.serverIP = serverIP;
this.serverPort = serverPort;
}

public void closeSelf(){
isRun = false;
}


public void send(String msg){
pw.println(msg);
pw.flush();
}


@Override

public void run() {
try {
socket = new Socket(serverIP, serverPort);
socket.setSoTimeout(5000);
dop = new DataOutputStream(socket.getOutputStream());
pw = new PrintWriter(socket.getOutputStream(),true);
is = socket.getInputStream();
dis = new DataInputStream(is);
} catch (IOException e) {
e.printStackTrace();
}
while (isRun){
try {
rcvLen = dis.read(buff);
if (rcvLen!=-1){
rcvMsg = new String(buff,0,rcvLen,"utf-8");
rcvMsgg = new SocketHelper().byte2hex(buff,rcvLen);
Log.i(TAG,"run收到消息: "+ new SocketHelper().byte2hex(buff,rcvLen));
...