Android 应用开发-蓝牙开关控制及设备扫描并展示

比眉伴天荒 2024-03-16 18:40 22阅读 0赞

前言：点击积累，贵在坚持，感谢你的阅览

页面基本布局如下图所示，Switch 开关控制蓝牙开启和关闭，左右两个列表展示已连接的蓝牙设备和未连接的蓝牙设备，每个设备只展示名字和地址，如果没有则展示null

![Image 1][]

1、申请权限：

<uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

2、在进去页面执行 onCreate生命周期时，进行权限检查，如果没有授权，则退出界面，保证后续代码执行是合法的

private static String[] PERMISSIONS = {
        "android.permission.BLUETOOTH",
        "android.permission.BLUETOOTH_ADMIN",
        "android.permission.ACCESS_FINE_LOCATION",
        "android.permission.ACCESS_COARSE_LOCATION"
    };
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        checkPermission();
    }
    
    private void checkPermission() {
        for(String permission : PERMISSIONS) {
            if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
                showtoast("请开通相关权限，否则无法正常使用本应用！");
                ActivityCompat.requestPermissions(this, PERMISSIONS, REQUEST_CODE);
                break;
            }
        }
    }
    
    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            //权限的申请结果返回
            case REQUEST_CODE: {
                boolean isAllPermissionPass = true;
                for(String permission : PERMISSIONS) {
                    if (ActivityCompat.checkSelfPermission(this, permission) != PackageManager.PERMISSION_GRANTED) {
                        isAllPermissionPass = false;
                        break;
                    }
                }
                if (isAllPermissionPass) {
                    showtoast("授权成功！");
                } else {
                    finish();
                }
            }
        }
    }
    
    private void showtoast(String content) {
        Toast.makeText(context, content, Toast.LENGTH_SHORT).show();
    }

3、蓝牙开关的控制

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (bluetoothAdapter == null) {
        //当前设备不支持蓝牙功能
    }
    bluetoothAdapter.enable();//打开蓝牙
    bluetoothAdapter.disable();//关闭蓝牙
    bluetoothAdapter.isEnabled()//返回蓝牙开关状态，true：开启，false：关闭
    bluetoothAdapter.startDiscovery();//开始扫描蓝牙设备

4、注册蓝牙相关的广播接收器

private BluetoothBroadcastReceive bluetoothBroadcastReceive;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initAndRegisterReceiver()
    }
    
    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(bluetoothBroadcastReceive);
    }
    
    private void initAndRegisterReceiver() {
        bluetoothBroadcastReceive = new BluetoothBroadcastReceive();
        IntentFilter intentFilter = new IntentFilter();
        //设备被发现
        intentFilter.addAction(BluetoothDevice.ACTION_FOUND);
        //搜索开始
        intentFilter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
        //搜索结束
        intentFilter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        //监视蓝牙关闭和打开的状态
        intentFilter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
        //监视蓝牙设备与APP连接的状态
        intentFilter.addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED);
        intentFilter.addAction(BluetoothDevice.ACTION_ACL_CONNECTED);
        //蓝牙配对
        intentFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
        //注册广播
        registerReceiver(bluetoothBroadcastReceive, intentFilter);
    }
    
    private class BluetoothBroadcastReceive extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            switch (action) {
                case BluetoothDevice.ACTION_FOUND:
                    BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    if (device.getBondState() == BluetoothDevice.BOND_BONDED) {
                        //已配对设备
                    } else {
                        //未配对设备
                    }
                    break;
                case BluetoothAdapter.ACTION_DISCOVERY_STARTED:
                    showtoast("开始搜索...");
                    break;
                case BluetoothAdapter.ACTION_DISCOVERY_FINISHED:
                    showtoast("搜索完成");
                    break;
                case BluetoothAdapter.ACTION_STATE_CHANGED:
                    int blueState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
                    switch (blueState) {
                        case BluetoothAdapter.STATE_TURNING_ON:
                            showtoast("蓝牙正在打开");
                            break;
                        case BluetoothAdapter.STATE_ON:
                            showtoast("蓝牙已经打开");
                            break;
                        case BluetoothAdapter.STATE_TURNING_OFF:
                            showtoast("蓝牙正在关闭");
                            break;
                        case BluetoothAdapter.STATE_OFF:
                            showtoast("蓝牙已经关闭");
                            break;
                    }
                    break;
                case BluetoothDevice.ACTION_ACL_CONNECTED:
                    BluetoothDevice b1 = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    showtoast("蓝牙设备已连接:" + b1.getName());
                    break;
                case BluetoothDevice.ACTION_ACL_DISCONNECTED:
                    BluetoothDevice b2 = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    showtoast("蓝牙设备已断开:" + b2.getName() + "," + b2.getAddress());
                    break;
                case BluetoothDevice.ACTION_BOND_STATE_CHANGED:
                    BluetoothDevice bluetoothDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    switch (bluetoothDevice.getBondState()) {
                        case BluetoothDevice.BOND_BONDED:
                            showtoast("配对完成");
                            break;
                        case BluetoothDevice.BOND_BONDING:
                            showtoast("正在配对");
                            break;
                        case BluetoothDevice.BOND_NONE:
                            showtoast("取消配对");
                            break;
                    }
                    break;
            }
        }
    }

5、蓝牙列表展示我用的是ListView，其适配器如下：

package com.sunway.bluetoothapplication;
    
    import android.bluetooth.BluetoothDevice;
    import android.content.Context;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseAdapter;
    import android.widget.TextView;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class BluetoothListAdapter extends BaseAdapter {
        private final List<BluetoothDevice> deviceList = new ArrayList<>();
        private Context context;
    
        public BluetoothListAdapter(Context context) {
            this.context = context;
        }
    
        public void setDeviceList(List<BluetoothDevice> deviceList) {
            this.deviceList.clear();
            this.deviceList.addAll(deviceList);
        }
    
        @Override
        public int getCount() {
            return deviceList.size();
        }
    
        @Override
        public Object getItem(int position) {
            return deviceList.get(position);
        }
    
        @Override
        public long getItemId(int position) {
            return position;
        }
    
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            BluetoothViewHolder bluetoothViewHolder;
            if (convertView == null) {
                convertView = LayoutInflater.from(context).inflate(R.layout.bluetootn_item, null);
                bluetoothViewHolder = new BluetoothViewHolder(convertView);
                convertView.setTag(bluetoothViewHolder);
            } else {
                bluetoothViewHolder = (BluetoothViewHolder) convertView.getTag();
            }
            bluetoothViewHolder.name.setText("名字：" + deviceList.get(position).getName());
            bluetoothViewHolder.address.setText("地址：" + deviceList.get(position).getAddress());
            return convertView;
        }
    
        private class BluetoothViewHolder {
            TextView name;
            TextView address;
    
            public BluetoothViewHolder(View itemView) {
                name = itemView.findViewById(R.id.name);
                address = itemView.findViewById(R.id.address);
            }
        }
    }

上面适配器中用到的layout/bluetootn\_item.xml 源码如下：

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    
        <TextView
            android:id="@+id/name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:textColor="#ff0000"/>
    
        <TextView
            android:id="@+id/address"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    </LinearLayout>

6、让名字不为空的蓝牙设备展示在前面，只需要对设备集合做一个简单的排序比较，其比较器可以这样写：

private final List<BluetoothDevice> bondedDeviceList = new ArrayList<>();
        
    private Comparator<BluetoothDevice> comparator = new Comparator<BluetoothDevice>() {
        @Override
        public int compare(BluetoothDevice o1, BluetoothDevice o2) {
            if (o1.getName() == null && o2.getName() != null) {
                return 1;
            }
            if (o1.getName() != null && o2.getName() == null) {
                return -1;
            }
            if (o1.getName() == null && o2.getName() == null) {
                return 0;
            }
            return 0;
        }
    };
    
    bondedDeviceList.sort(comparator);

[Image 1]: