藍牙

package com.example.vicky;

import androidx.appcompat.app.AppCompatActivity;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import java.util.Set;

public class MainActivity extends AppCompatActivity {
    private ProgressDialog progressDialog;

    private BluetoothAdapter mBluetoothAdapter;
    private TextView tvDevice;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tvDevice = (TextView)findViewById(R.id.tvDevice);
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        Set<BluetoothDevice> pairedDevice = mBluetoothAdapter.getBondedDevices();
        if( pairedDevice.size() > 0 ) {
            for (BluetoothDevice device : pairedDevice) {
                tvDevice.append(device.getName() + " : " + device.getAddress());
            }
        }

        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        this.registerReceiver(receiver,filter);

        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(receiver,filter);

    }

    public void onClick_search(View view) {
        if(mBluetoothAdapter.isDiscovering()) {
            mBluetoothAdapter.cancelDiscovery();
        }
        mBluetoothAdapter.startDiscovery();
        if (progressDialog == null) {
            progressDialog = new ProgressDialog(this);
        }
        progressDialog.setMessage("正在搜索，請稍後！");
        progressDialog.show();
    }

    private final BroadcastReceiver receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if(BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if(device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    tvDevice.append(device.getName() + " : " + device.getAddress() + "\n");
                }
            } else if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                setProgressBarVisibility(false);
                setTitle("已搜索完成");
            }
        }
    };
}