蓝牙连接不起作用-为什么这样做？

Question

我使用Unity来制作我的Android应用程序，所以我制作了Android插件。

在此插件中，我想将Android连接到其他蓝牙模块（我不知道模块名称是什么）

这是我的代码：

    package com.jiho.myplugin;

    import android.app.Activity;
    import android.bluetooth.BluetoothAdapter;
    import android.bluetooth.BluetoothDevice;
    import android.bluetooth.BluetoothSocket;
    import android.content.Context;
    import android.content.Intent;
    import android.os.ParcelUuid;
    import android.widget.Toast;

    import com.unity3d.player.UnityPlayer;

    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.util.ArrayList;
    import java.util.Arrays;
    import java.util.List;
    import java.util.Set;
    import java.util.UUID;


    public class Uplugin{

        private static Uplugin m_instance;
        public  static Context context;

        private static BluetoothAdapter myBluetoothAdapter;

        private static UUID remoteUUID;

        private static BluetoothSocket sock;

        private static BluetoothDevice remoteDevice;

        private static String remoteAddress;

        public static Uplugin instance(){
            if(m_instance == null){
                m_instance = new Uplugin();
            }
            return m_instance;
        }
        private void SetContext(Context ct)
        {
            context = ct;
        }

        private static void bondBluetooth(Activity activity) {
            myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
            //pairingList
            List<String> pairingList = new ArrayList<>();

            Toast.makeText(context, "start!", Toast.LENGTH_SHORT).show();

            if(!myBluetoothAdapter.isEnabled())
            {

                myBluetoothAdapter.enable();
            }

            while(true)
            {
                if(myBluetoothAdapter.isEnabled())
                {
                    break;
                }
            }


            Set<BluetoothDevice> pairedDevices =                     myBluetoothAdapter.getBondedDevices();

            if(pairedDevices.size()>0) {
                for (BluetoothDevice device : pairedDevices) {

                    if(device.getName().contains("TANDA"))
                    {

                        remoteDevice = device;
                        remoteAddress = device.getAddress();

                        ParcelUuid list[] = device.getUuids();
                        remoteUUID = UUID.fromString(list[0].toString());
                        break;
                    }
                }
            }
            else
            {
                Toast.makeText(context, "no pair", Toast.LENGTH_SHORT).show();
            }


        }
        private static void ConnectBluetooth(Activity activity)
        {
            BluetoothDevice mRemoteDevice;
            BluetoothSocket mBluetoothSock = null;
            mRemoteDevice = myBluetoothAdapter.getRemoteDevice(remoteAddress);
            try{
                mBluetoothSock = mRemoteDevice.createInsecureRfcommSocketToServiceRecord(remoteUUID);
            } catch (IOException e){
                Toast.makeText(context, "create error", Toast.LENGTH_SHORT).show();
            }

            sock = mBluetoothSock;
            myBluetoothAdapter.cancelDiscovery();
            try{
                sock.connect();
            } catch(IOException e){ Toast.makeText(context, "connect error", Toast.LENGTH_SHORT).show();}

        }

In my Unity, i call "StratBluetooth()" first and than call "ConnectBluetooth()"

when i run this code first time, it was work.
but since next time it doesnt work at all.

createInsecureRfcommSocket（）和connect（）在代码中正常工作，但没有成功 到catch(IOException e)以及isConnected() == true

它在我的Android中没有连接。