前言

上一篇文章给大家分享了Android蓝牙的基础知识和基础用法，不过上一篇都是一些零散碎片化的程序，这一篇给大家分享Android蓝牙开发实战项目的初步使用

效果演示 :

Android蓝牙搜索，配对，连接，通信

Android蓝牙实战开发步骤

1.新建Android项目添加蓝牙权限

下图所示：MyBluetoothDemo为刚刚创建的Android空项目，我们现在清单文件中把我们需要用到的权限声明一下，其中定位权限还需要做动态申请

2.封装BluetoothAdapter类

BluetoothAdapter类提供了常用的蓝牙API，我这里创建了一个BlueToothController类，小编这里是先将这些API封装到了一个BlueToothController类中，方便后续使用和操作

package com.example.mybluetoothdemo;

import android.annotation.SuppressLint;
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 java.util.ArrayList;
import java.util.List;

public class BlueToothController {

    private BluetoothAdapter mBluetoothAdapter;

    public BlueToothController(){
        //初始化蓝牙适配器
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    }

    public BluetoothAdapter getBluetoothAdapter() {
        return mBluetoothAdapter;
    }




    /**
     * 检查设备是否支持蓝牙
     */
    public boolean isBluetoothSupport(){
        if(mBluetoothAdapter == null){
            return false;
        }else {
            return true;
        }
    }

    /**
     * 检查该设备蓝牙是否开启
     */
    public boolean isBluetoothEnabled(){
        if(mBluetoothAdapter.isEnabled()){
            return true;
        }else {
            return false;
        }
    }


    /**
     * 打开蓝牙
     */
    @SuppressLint("MissingPermission")
    public void turnOnBlueTooth(Activity activity, int requestCode) {
        Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        activity.startActivityForResult(intent, requestCode);
    }


    /**
     * 打开蓝牙可见性
     */
    @SuppressLint("MissingPermission")
    public void enableVisibily(Context context){
        Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        intent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION,300);
        context.startActivity(intent);
    }


    /**
     * 停止查找设备
     */
    @SuppressLint("MissingPermission")
    public void cancelFindDevice(){
        mBluetoothAdapter.cancelDiscovery();
    }

    /**
     * 判断当前设备是否在查找蓝牙设备
     */
    @SuppressLint("MissingPermission")
    public boolean isStartDiscovering(){
        if(mBluetoothAdapter.isDiscovering()){
            return true;
        }else {
            return false;
        }
    }

    /**
     * 判断当前设备是否未在查找蓝牙设备
     */
    @SuppressLint("MissingPermission")
    public boolean isCancelDiscovering(){
        if(!mBluetoothAdapter.isDiscovering()){
            return true;
        }else {
            return false;
        }
    }


    /**
     * 查找设备
     */
    @SuppressLint("MissingPermission")
    public void findDevice() {
        mBluetoothAdapter.startDiscovery();
    }


    /**
     * 获取已绑定设备
     */
    @SuppressLint("MissingPermission")
    public List<BluetoothDevice> getBondedDeviceList(){
        return new ArrayList<>(mBluetoothAdapter.getBondedDevices());
    }

    /**
     * 判断蓝牙是否连接
     */
    @SuppressLint("MissingPermission")
    public boolean isConnectBlue(BluetoothSocket bluetoothSocket){
        return bluetoothSocket !=null && bluetoothSocket.isConnected();
    }
}

3. 编写UI页面

activity_main.xml：这是我们MainActivity的UI，放置了一个ListView和一个按钮，ListView用来显示搜索到的蓝牙设备和已配对的蓝牙设备，Button控件用来与连接后的设备发送信息时使用

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="16.dp"
    android:paddingRight="16.dp"
    android:paddingBottom="16.dp">

    <ListView
        android:id="@+id/device_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="#e90423"
        android:dividerHeight="1px"
        >
    </ListView>

    <Button
        android:id="@+id/btn_write_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:text="发送消息"/>

</RelativeLayout>

既然有了ListView，那就一定有ListView的每条子元素UI，新建list_item.xml

list_item.xml: 用来显示ListView列表的子内容

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:orientation="horizontal"
    android:layout_height="wrap_content">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <TextView android:id="@+id/text1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"

            android:textStyle="bold"
            android:textSize="18sp"/>

        <TextView android:id="@+id/text3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"

            android:textSize="13sp"/>

    </LinearLayout>

</LinearLayout>

然后，我们再为页面右上角写一个menu列表按钮，新建menu_main.xml

menu_main.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    tools:context=".MainActivity" >

    <item
        android:id="@+id/is_bluetooth_support"
        android:title="@string/is_bluetooth_support"
        android:orderInCategory="1" />

    <item
        android:id="@+id/is_bluetooth_enabled"
        android:title="@string/is_bluetooth_enabled"
        android:orderInCategory="2" />

    <item
        android:id="@+id/bonded_device"
        android:title="@string/bonded_device"
        android:orderInCategory="2" />

    <item
        android:id="@+id/find_device"
        android:title="@string/find_device"
        android:orderInCategory="3" />


</menu>

最后，再为大家分享一下string.xml字符串配置信息

4. 蓝牙列表适配器

创建DeviceAdapter类，具体如下图所示：

package com.example.mybluetoothdemo;

import android.annotation.SuppressLint;
import android.bluetooth.BluetoothDevice;
import android.content.Context;
import android.graphics.Color;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

public class DeviceAdapter extends BaseAdapter{

    private List<BluetoothDevice> mData;
    private Context mContext;

    public DeviceAdapter(List<BluetoothDevice> data, Context context){
        mData = data;
        mContext = context.getApplicationContext();
    }

    @Override
    public int getCount() {
        return mData.size();
    }

    @Override
    public Object getItem(int i) {
        return mData.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @SuppressLint("MissingPermission")
    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        View itemView = view;
        //复用view，优化性能
        if(itemView == null){
            itemView = LayoutInflater.from(mContext).inflate(R.layout.list_item, viewGroup,false);
        }


        TextView text1 = itemView.findViewById(R.id.text1);
        TextView text2 = itemView.findViewById(R.id.text3);

        text1.setTextColor(Color.BLACK);
        text2.setTextColor(Color.BLACK);

        //获取对应的蓝牙设备
        BluetoothDevice device = (BluetoothDevice) getItem(i);


        //显示设备名称
        if(device.getName()==null){
            text1.setText("N/A");
        }else {
            text1.setText(device.getName());
        }

        //显示设备地址
        text2.setText(device.getAddress());

        return itemView;
    }

    //刷新列表，防止搜索结果重复出现
    public void refresh(List<BluetoothDevice> data){
        mData = data;
        notifyDataSetChanged();
    }

}

5. 蓝牙搜索，配对，连接，通信

小编这里为了让大家方便，便将搜索，配对，连接都写在了MainActivity中了

package com.example.mybluetoothdemo;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.Manifest;
import android.annotation.SuppressLint;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;

import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothProfile;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;

import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;


import java.util.ArrayList;
import java.util.List;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

    private final String TAG = "yf";

    private BlueToothController blueToothController = new BlueToothController();

    private static final int REQUEST_ENABLE_BT = 1;

    private ListView listView;
    private DeviceAdapter blueToothDeviceAdapter,bondBlueToothDeviceAdapter;

    private List<BluetoothDevice> deviceList = new ArrayList<>();
    private List<BluetoothDevice> bondedDeviceList = new ArrayList<>();

    private BluetoothDevice device;

    private BluetoothGatt bluetoothGatt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initUI();

        //判断是否有访问位置的权限，没有权限，直接申请位置权限
        isPermission();


        registerBluetoothReceiver();
    }



    @SuppressLint("MissingPermission")
    private void initUI(){
        listView = findViewById(R.id.device_list);
        blueToothDeviceAdapter = new DeviceAdapter(deviceList,this);
        bondBlueToothDeviceAdapter = new DeviceAdapter(bondedDeviceList,this);

        findViewById(R.id.btn_write_1).setOnClickListener(view -> {
            if (null == mWriter){
                Log.e("cx12345","ble：发送失败：null == writer !!!!");
            }else {
                mWriter.setValue(new byte[]{
                        (byte)0x0c,
                        (byte)0x11,
                        (byte)0x09,
                        (byte)0x41,
                        (byte)0x23,
                        (byte)0x00,
                        (byte)0x01,
                        (byte)0x03,
                        (byte)0xFF
                });

                mGatt.writeCharacteristic(mWriter);
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main,menu);
        return true;
    }

    @SuppressLint("MissingPermission")
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        switch (id){
            case R.id.is_bluetooth_support:
                if (blueToothController.isBluetoothSupport()){
                    Toast.makeText(MainActivity.this, "该设备支持蓝牙功能", Toast.LENGTH_SHORT).show();
                }else {
                    Toast.makeText(MainActivity.this, "该设备不支持蓝牙功能", Toast.LENGTH_SHORT).show();
                }
                break;
            case R.id.is_bluetooth_enabled:
                if (blueToothController.isBluetoothEnabled()){
                    Toast.makeText(MainActivity.this, "蓝牙已开启", Toast.LENGTH_SHORT).show();
                }else {
                    blueToothController.turnOnBlueTooth(this,REQUEST_ENABLE_BT);
                }
                break;
            case R.id.bonded_device:
                setTitle("已配对的设备");

                bondedDeviceList = blueToothController.getBondedDeviceList();
                listView.setAdapter(bondBlueToothDeviceAdapter);
                bondBlueToothDeviceAdapter.refresh(bondedDeviceList);


                break;
            case R.id.find_device:
                setTitle("可用设备");
                if(blueToothController.isStartDiscovering()){
                    blueToothController.cancelFindDevice();
                }
                blueToothController.findDevice();
//                blueToothController.getBluetoothAdapter().startLeScan(leScanCallback);
                listView.setAdapter(blueToothDeviceAdapter);
                blueToothDeviceAdapter.refresh(deviceList);
                listView.setOnItemClickListener(deviceBluetooth);
                break;
            default:
                break;
        }
        return super.onOptionsItemSelected(item);
    }


    private AdapterView.OnItemClickListener deviceBluetooth = new AdapterView.OnItemClickListener() {
        @SuppressLint("MissingPermission")
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
            device = deviceList.get(i);
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                //蓝牙绑定
//                device.createBond();

                //Gatt协议连接蓝牙
                bluetoothGatt = device.connectGatt(MainActivity.this,true,mGattCallback);
                bluetoothGatt.connect();
            }
        }
    };




    //动态获取位置权限
    private void isPermission(){
        if ((checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
                || (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)) {
            requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 200);
        }
    }




    @SuppressLint("MissingPermission")
    @Override
    protected void onDestroy() {
        super.onDestroy();
        // 停止设备搜索
        blueToothController.getBluetoothAdapter().cancelDiscovery();
        //注销广播
        unregisterReceiver(receiver);
    }


    private void registerBluetoothReceiver(){
        //filter注册广播接收器
        IntentFilter filter = new IntentFilter();


        //蓝牙当前状态
        filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);


        //开始扫描蓝牙设备广播
        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);

        //找到蓝牙设备广播
        filter.addAction(BluetoothDevice.ACTION_FOUND);

        //扫描蓝牙设备结束广播
        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

        //蓝牙设备配对状态改变广播
        filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);

        //设备扫描模式改变广播
        filter.addAction(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);

        registerReceiver(receiver, filter);
    }

    //处理找到蓝牙设备和搜索完成的广播消息
    BroadcastReceiver receiver = new BroadcastReceiver() {

        @SuppressLint("MissingPermission")
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            //开始查找设备
            if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)){
                //初始化适配器列表
                deviceList.clear();
                bondedDeviceList.clear();
                blueToothDeviceAdapter.refresh(deviceList);
                bondBlueToothDeviceAdapter.refresh((bondedDeviceList));
            }
            //找到蓝牙设备
            else if(BluetoothDevice.ACTION_FOUND.equals(action)){
                //搜到蓝牙设备
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

                    //把搜索到的设备添加到已找到列表中，显示它的信息
                    deviceList.add(device);
                    blueToothDeviceAdapter.refresh(deviceList);

            }
            //查找设备结束
            else if(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)){
                //搜索完毕
                Toast.makeText(MainActivity.this, "选择要配对的蓝牙设备", Toast.LENGTH_SHORT).show();
                blueToothDeviceAdapter.refresh(deviceList);
            }
            //配对状态
            else if(BluetoothDevice.ACTION_BOND_STATE_CHANGED.equals(action)){
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if(device == null){
                    Toast.makeText(MainActivity.this, "无设备", Toast.LENGTH_SHORT).show();
                    return;
                }

                int state = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE,0);
                if(state == BluetoothDevice.BOND_BONDED){
                    Toast.makeText(MainActivity.this, "已配对", Toast.LENGTH_SHORT).show();
                }else if(state == BluetoothDevice.BOND_BONDING){
                    Toast.makeText(MainActivity.this, "正在配对", Toast.LENGTH_SHORT).show();
                }else if(state == BluetoothDevice.BOND_NONE){
                    Toast.makeText(MainActivity.this, "未配对", Toast.LENGTH_SHORT).show();
                }
            }

        }
    };

    private BluetoothGatt mGatt;
    private BluetoothGattCharacteristic mWriter;

    /**
     * @param gatt     返回连接建立的gatt对象
     * @param status   返回的是此次gatt操作的结果，成功了返回0
     * @param newState 每次client连接或断开连接状态变化，
     *                 STATE_CONNECTED 0，
     *                 STATE_CONNECTING 1,
     *                 STATE_DISCONNECTED 2,
     *                 STATE_DISCONNECTING 3
     */

    private BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
        @SuppressLint("MissingPermission")
        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {

            //连接成功
            if(newState == BluetoothProfile.STATE_CONNECTED){
                //进行服务发现
                gatt.discoverServices();
                Log.d(TAG,"连接成功");
            }else if(newState == BluetoothProfile.STATE_DISCONNECTED){
                //连接断开，处理断开逻辑
                Log.d(TAG,"连接断开");
            }
        }

        @SuppressLint("MissingPermission")
        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
            Log.d(TAG,"onServicesDiscovered : " + status + " ==>> " + gatt.toString());

            //发现服务成功，处理服务和特征值
            if(status == BluetoothGatt.GATT_SUCCESS){
                //发送消息
                mGatt = gatt;
                BluetoothGattService service = gatt.getService(UUID.fromString("0000180a-0000-1000-8000-00805F9B34FB"));
                mWriter = service.getCharacteristic(UUID.fromString("00002ad9-0000-1000-8000-00805F9B34FB"));

                //打开消息通知
                mGatt.setCharacteristicNotification(mWriter,true);
                BluetoothGattDescriptor descriptor = mWriter.getDescriptor(UUID.fromString("00002902-0000-1000-8000-00805f9b34fb"));
                descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
                mGatt.writeDescriptor(descriptor);
            }else {
                Log.d(TAG,"发现服务失败");
            }

        }


        @Override
        public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
            Log.e(TAG,"onCharacteristicRead " + status);
            //读取特征成功，处理特征值
            if(status == BluetoothGatt.GATT_SUCCESS){

            }
        }

        @Override
        public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
            Log.e(TAG,"onCharacteristicWrite " + status);
            //写入特征成功
            if(status == BluetoothGatt.GATT_SUCCESS){
                Log.d(TAG,"发送成功");
            }else {
                Log.d(TAG,"发送失败");
            }
        }

        @Override
        public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {

            //接收到数据
            byte[] data = characteristic.getValue();

            //处理接收到的数据
            Log.d(TAG,"Received data: " + bytesToHexFun2(data));
        }

        @Override
        public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
            super.onDescriptorRead(gatt, descriptor, status);
        }

        @Override
        public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
            super.onDescriptorWrite(gatt, descriptor, status);
        }

        @Override
        public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
            super.onReliableWriteCompleted(gatt, status);
        }

        @Override
        public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
            super.onReadRemoteRssi(gatt, rssi, status);
        }

        @Override
        public void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {
            super.onMtuChanged(gatt, mtu, status);
        }

        @Override
        public void onServiceChanged(@NonNull BluetoothGatt gatt) {
            super.onServiceChanged(gatt);
        }

        @Override
        public void onPhyUpdate(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
            super.onPhyUpdate(gatt, txPhy, rxPhy, status);
        }

        @Override
        public void onPhyRead(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
            super.onPhyRead(gatt, txPhy, rxPhy, status);
        }
    };

    private char[] HEX_CHAR = {'0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    private  String bytesToHexFun2(byte[] bytes) {
        char[] buf = new char[bytes.length * 2];
        int index = 0;
        for(byte b : bytes) { // 利用位运算进行转换，可以看作方法一的变种
            buf[index++] = HEX_CHAR[b >>> 4 & 0xf];
            buf[index++] = HEX_CHAR[b & 0xf];
        }

        return new String(buf);
    }

}

到此为止，我们的程序就到这里了，蓝牙搜索，配对，连接，通信便已经成功实现了，大家可以把代码copy一下拿去运行，具体效果演示图在文章最上方，大家还想了解更多关于Android蓝牙开发的可以继续看我下一篇给大家的分享