蓝牙通信-搜索附近的蓝牙设备

 与其他设备通信通信之前需要搜索周围的蓝牙设备。

怎么搜索呢？？

1.如果数据中已经和某些蓝牙设备绑定，可以使用BluetoothAdapter.getBondedDevices();方法获得已经绑定的蓝牙设备列表

2.搜索周围的蓝牙设备受用BluetoothAdapter.startDiscovery()方法

3.搜索到的蓝牙设备都是通过广播返回，so..。需要注册广播接收器来获得已经搜索到的蓝牙设备。

下面我们看一下demo：

我们在布局文件中放一个按钮和一个显示文本TextView。

我们点击Button时，开始搜索附近的蓝牙设备。将搜索到的蓝牙设备追加到TextView上，我们将绑定的和搜索到的都显示在TextView上。

布局文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <Button        android:id="@+id/button_id"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClick_Search"        android:text="搜索蓝牙设备" />    <TextView        android:id="@+id/tvDevices"        android:layout_width="fill_parent"        android:layout_below="@+id/button_id"        android:layout_height="wrap_content" /></RelativeLayout>

JAVA文件：

package com.example.search_bluetooth_devices;import java.util.Set;import android.os.Bundle;import android.app.Activity;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.view.Menu;import android.view.View;import android.view.Window;import android.widget.TextView;public class MainActivity extends Activity {private TextView mTextView;private BluetoothAdapter mBluetoothAdapter;private BroadcastReceiver mReceiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {// TODO Auto-generated method stubString action = intent.getAction();// 获得已经搜索到的蓝牙设备if (action.equals(BluetoothDevice.ACTION_FOUND)) {BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);// 搜索到的不是已经绑定的蓝牙设备if (device.getBondState() != BluetoothDevice.BOND_BONDED) {// 显示在TextView上mTextView.append(device.getName() + ":"+ device.getAddress()+"\n");}// 搜索完成} else if (action.equals(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)) {setProgressBarIndeterminateVisibility(false);setTitle("搜索蓝牙设备");}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);setContentView(R.layout.activity_main);mTextView = (TextView) findViewById(R.id.tvDevices);mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();// 获取所有已经绑定的蓝牙设备Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();if (devices.size() > 0) {for (BluetoothDevice bluetoothDevice : devices) {mTextView.append(bluetoothDevice.getName() + ":"+ bluetoothDevice.getAddress() + "\n\n");}}// 注册用以接收到已搜索到的蓝牙设备的receiverIntentFilter mFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);registerReceiver(mReceiver, mFilter);// 注册搜索完时的receivermFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);registerReceiver(mReceiver, mFilter);}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();//解除注册unregisterReceiver(mReceiver);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}public void onClick_Search(View v) {setProgressBarIndeterminateVisibility(true);setTitle("正在扫描....");// 如果正在搜索，就先取消搜索if (mBluetoothAdapter.isDiscovering()) {mBluetoothAdapter.cancelDiscovery();}// 开始搜索蓝牙设备,搜索到的蓝牙设备通过广播返回mBluetoothAdapter.startDiscovery();}}

配置文件：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.search_bluetooth_devices"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="17" />    <uses-permission android:name="android.permission.BLUETOOTH"/>    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.example.search_bluetooth_devices.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

运行结果：

本机绑定的蓝牙设备一开始就显示（第一张图），点击搜索蓝牙设备后（第2张图）