與其他裝置通訊通訊之前需要搜尋周圍的藍芽裝置。

怎麼搜尋呢？？

1.如果資料中已經和某些藍芽裝置繫結，可以使用BluetoothAdapter.getBondedDevices();方法獲得已經繫結的藍芽裝置列表

2.搜尋周圍的藍芽裝置受用BluetoothAdapter.startDiscovery()方法

3.搜尋到的藍芽裝置都是通過廣播返回，so..。需要註冊廣播接收器來獲得已經搜尋到的藍芽裝置。

下面我們看一下demo：

我們在佈局檔案中放一個按鈕和一個顯示文字TextView。

我們點選Button時，開始搜尋附近的藍芽裝置。將搜尋到的藍芽裝置追加到TextView上，我們將繫結的和搜尋到的都顯示在TextView上。

佈局檔案：

<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="搜尋藍芽裝置" />

    <TextView
        android:id="@+id/tvDevices"
        android:layout_width="fill_parent"
        android:layout_below="@+id/button_id"
        android:layout_height="wrap_content" />

</RelativeLayout>
 

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() {

		@Override
		public void onReceive(Context context, Intent intent) {
			// TODO Auto-generated method stub

			String action = intent.getAction();
			// 獲得已經搜尋到的藍芽裝置
			if (action.equals(BluetoothDevice.ACTION_FOUND)) {
				BluetoothDevice device = intent
						.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
				// 搜尋到的不是已經繫結的藍芽裝置
				if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
					// 顯示在TextView上
					mTextView.append(device.getName() + ":"
							+ device.getAddress()+"\n");
				}
				// 搜尋完成
			} else if (action
					.equals(BluetoothAdapter.ACTION_DISCOVERY_FINISHED)) {
				setProgressBarIndeterminateVisibility(false);
				setTitle("搜尋藍芽裝置");
			}
		}
	};

	@Override
	protected 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();
		// 獲取所有已經繫結的藍芽裝置
		Set<BluetoothDevice> devices = mBluetoothAdapter.getBondedDevices();
		if (devices.size() > 0) {
			for (BluetoothDevice bluetoothDevice : devices) {
				mTextView.append(bluetoothDevice.getName() + ":"
						+ bluetoothDevice.getAddress() + "\n\n");
			}
		}
		// 註冊用以接收到已搜尋到的藍芽裝置的receiver
		IntentFilter mFilter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
		registerReceiver(mReceiver, mFilter);
		// 註冊搜尋完時的receiver
		mFilter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
		registerReceiver(mReceiver, mFilter);
	}

	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		//解除註冊
		unregisterReceiver(mReceiver);
	}

	@Override
	public 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("正在掃描....");
		// 如果正在搜尋，就先取消搜尋
		if (mBluetoothAdapter.isDiscovering()) {
			mBluetoothAdapter.cancelDiscovery();
		}
		// 開始搜尋藍芽裝置,搜尋到的藍芽裝置通過廣播返回
		mBluetoothAdapter.startDiscovery();
	}

}
 

<?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>

本機繫結的藍芽裝置一開始就顯示（第一張圖），點選搜尋藍芽裝置後（第2張圖）