Android藍牙教程

藍牙 是一種無線交換數據的方式。愛掏網 - it200.com Android提供了藍牙API來執行多個任務，例如：

• 掃描藍牙設備
• 連接和傳輸數據到其他設備
• 管理多個連接等

android.bluetooth包提供了許多接口類來處理藍牙，例如：

• BluetoothAdapter
• BluetoothDevice
• BluetoothSocket
• BluetoothServerSocket
• BluetoothClass
• BluetoothProfile
• BluetoothProfile.ServiceListener
• BluetoothHeadset
• BluetoothA2dp
• BluetoothHealth
• BluetoothHealthCallback
• BluetoothHealthAppConfiguration

BluetoothAdapter類

通過BluetoothAdapter類的幫助，我們可以執行一些基本任務，如啟動設備發現，查詢已配對的設備列表，創建BluetoothServerSocket實例以偵聽連接請求等。愛掏網 - it200.com

BluetoothAdapter類的常量

BluetoothAdapter類提供了許多常量。愛掏網 - it200.com其中一些如下所示：

• String ACTION_REQUEST_ENABLE
• String ACTION_REQUEST_DISCOVERABLE
• String ACTION_DISCOVERY_STARTED
• String ACTION_DISCOVERY_FINISHED

BluetoothAdapter類的方法

BluetoothAdapter類的常用方法如下：

• static synchronized BluetoothAdapter getDefaultAdapter() 返回BluetoothAdapter的實例。愛掏網 - it200.com
• boolean enable() 如果藍牙適配器已禁用，則啟用藍牙適配器。愛掏網 - it200.com
• boolean isEnabled() 如果藍牙適配器已啟用，則返回true。愛掏網 - it200.com
• boolean disable() 如果藍牙適配器已啟用，則禁用藍牙適配器。愛掏網 - it200.com
• String getName() 返回藍牙適配器的名稱。愛掏網 - it200.com
• boolean setName(String name) 更改藍牙名稱。愛掏網 - it200.com
• int getState() 返回本地藍牙適配器的當前狀態。愛掏網 - it200.com
• Set <BluetoothDevice> getBondedDevices() 返回一組已配對的BluetoothDevice對象。愛掏網 - it200.com
• boolean startDiscovery() 啟動發現過程。愛掏網 - it200.com

Android藍牙示例：以編程方式啟用、禁用和使藍牙可被發現

你只需要寫幾行代碼，就可以啟用或禁用藍牙。愛掏網 - it200.com

activity_main.xml

從面板中拖動一個文本視圖和三個按鈕，現在activity_main.xml文件將如下所示:

<RelativeLayout xmlns:androclass="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <TextView android:text=""
     android:id="@+id/out" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content">
    </TextView>
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="30dp"
        android:layout_marginTop="49dp"
        android:text="TURN_ON" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button1"
        android:layout_below="@+id/button1"
        android:layout_marginTop="27dp"
        android:text="DISCOVERABLE" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/button2"
        android:layout_below="@+id/button2"
        android:layout_marginTop="28dp"
        android:text="TURN_OFF" />

</RelativeLayout>

提供權限

您需要在AndroidManifest.xml文件中提供以下權限。愛掏網 - it200.com

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

下面是AndroidManifest.xml文件的完整代碼。愛掏網 - it200.com

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:androclass="http://schemas.android.com/apk/res/android"
    package="com.example.bluetooth"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="16" />

    <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.bluetooth.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>

Activity類

讓我們編寫代碼來啟用、禁用和使藍牙可發現。愛掏網 - it200.com

package com.example.bluetooth;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {
      private static final int REQUEST_ENABLE_BT = 0;
      private static final int REQUEST_DISCOVERABLE_BT = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    final TextView out=(TextView)findViewById(R.id.out);
    final Button button1 = (Button) findViewById(R.id.button1);
    final Button button2 = (Button) findViewById(R.id.button2);
    final Button button3 = (Button) findViewById(R.id.button3);
    final BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (mBluetoothAdapter == null) {
       out.append("device not supported");
    }
    button1.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            if (!mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
            }
        }
    });
    button2.setOnClickListener(new View.OnClickListener() {
     @Override
        public void onClick(View arg0) {
            if (!mBluetoothAdapter.isDiscovering()) {
                  //out.append("MAKING YOUR DEVICE DISCOVERABLE");
                   Toast.makeText(getApplicationContext(), "MAKING YOUR DEVICE DISCOVERABLE",
             Toast.LENGTH_LONG);

                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
                startActivityForResult(enableBtIntent, REQUEST_DISCOVERABLE_BT);

            }
        }
    });
    button3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {   
            mBluetoothAdapter.disable();
            //out.append("TURN_OFF BLUETOOTH");
            Toast.makeText(getApplicationContext(), "TURNING_OFF BLUETOOTH", Toast.LENGTH_LONG);

            }
    });
}

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}