Android 實現藍牙打印的功能

第一步：首先需要一個藍牙打印工具類
import android.bluetooth.BluetoothSocket;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;

import com.github.promeg.pinyinhelper.Pinyin;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.Calendar;

/**

• 藍牙打印工具類
  */
  public class PrintUtil {

  private OutputStreamWriter mWriter = null;
  private OutputStream mOutputStream = null;

  public final static int WIDTH_PIXEL = 384;
  public final static int IMAGE_SIZE = 320;
  private static String myTime;

  /**

  • 初始化Pos實例
  • @param encoding 編碼
  • @throws IOException
    */
    public PrintUtil(OutputStream outputStream, String encoding) throws IOException {
    mWriter = new OutputStreamWriter(outputStream, encoding);
    mOutputStream = outputStream;
    initPrinter();
    }

  public void print(byte[] bs) throws IOException {
  mOutputStream.write(bs);
  }

  public void printRawBytes(byte[] bytes) throws IOException {
  mOutputStream.write(bytes);
  mOutputStream.flush();
  }

  /**

  • 初始化打印機
  • @throws IOException
    */
    public void initPrinter() throws IOException {
    mWriter.write(0x1B);
    mWriter.write(0x40);
    mWriter.flush();
    //獲取當前時間
    getTime();
    }

  /**

  • 打印換行
  • @return length 需要打印的空行數
  • @throws IOException
    */
    public void printLine(int lineNum) throws IOException {
    for (int i = 0; i < lineNum; i++) {
    mWriter.write("\n");
    }
    mWriter.flush();
    }

  /**

  • 打印換行(只換一行)
  • @throws IOException
    */
    public void printLine() throws IOException {
    printLine(1);
    }

  /**

  • 打印空白(一個Tab的位置，約4個漢字)
  • @param length 需要打印空白的長度,
  • @throws IOException
    */
    public void printTabSpace(int length) throws IOException {
    for (int i = 0; i < length; i++) {
    mWriter.write("\t");
    }
    mWriter.flush();
    }

  /**

  • 絕對打印位置
  • @return
  • @throws IOException
    */
    public byte[] setLocation(int offset) throws IOException {
    byte[] bs = new byte[4];
    bs[0] = 0x1B;
    bs[1] = 0x24;
    bs[2] = (byte) (offset % 256);
    bs[3] = (byte) (offset / 256);
    return bs;
    }

  public byte[] getGbk(String stText) throws IOException {
  byte[] returnText = stText.getBytes(“GBK”); // 必須放在try內纔可以
  return returnText;
  }

  private int getStringPixLength(String str) {
  int pixLength = 0;
  char c;
  for (int i = 0; i < str.length(); i++) {
  c = str.charAt(i);
  if (Pinyin.isChinese©) {
  pixLength += 24;
  } else {
  pixLength += 12;
  }
  }
  return pixLength;
  }

  public int getOffset(String str) {
  return WIDTH_PIXEL - getStringPixLength(str);
  }

  /**

  • 打印文字
  • @param text
  • @throws IOException
    */
    public void printText(String text) throws IOException {
    mWriter.write(text);
    mWriter.flush();
    }

  /**

  • 對齊0:左對齊，1：居中，2：右對齊
    */
    public void printAlignment(int alignment) throws IOException {
    mWriter.write(0x1b);
    mWriter.write(0x61);
    mWriter.write(alignment);
    }

  public void printLargeText(String text) throws IOException {

   mWriter.write(0x1b);
   mWriter.write(0x21);
   mWriter.write(48);
  
   mWriter.write(text);
  
   mWriter.write(0x1b);
   mWriter.write(0x21);
   mWriter.write(0);
  
   mWriter.flush();
  

  }

  public void printTwoColumn(String title, String content) throws IOException {
  int iNum = 0;
  byte[] byteBuffer = new byte[100];
  byte[] tmp;

   tmp = getGbk(title);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = setLocation(getOffset(content));
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = getGbk(content);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
  
   print(byteBuffer);
  

  }

  public void printThreeColumn(String left, String middle, String right) throws IOException {
  int iNum = 0;
  byte[] byteBuffer = new byte[200];
  byte[] tmp = new byte[0];

   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = getGbk(left);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   int pixLength = getStringPixLength(left) % WIDTH_PIXEL;
   if (pixLength > WIDTH_PIXEL / 2 || pixLength == 0) {
       middle = "\n\t\t" + middle;
   }
  
   tmp = setLocation(192);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = getGbk(middle);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = setLocation(getOffset(right));
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
   iNum += tmp.length;
  
   tmp = getGbk(right);
   System.arraycopy(tmp, 0, byteBuffer, iNum, tmp.length);
  
   print(byteBuffer);
  

  }

  public void printDashLine() throws IOException {
  printText("--------------------------------");
  }

  public void printBitmap(Bitmap bmp) throws IOException {
  bmp = compressPic(bmp);
  byte[] bmpByteArray = draw2PxPoint(bmp);
  printRawBytes(bmpByteArray);
  }

  /*************************************************************************

  • 假設一個360*360的圖片，分辨率設爲24, 共分15行打印 每一行,是一個 360 * 24 的點陣,y軸有24個點,存儲在3個byte裏面。

  • 即每個byte存儲8個像素點信息。因爲只有黑白兩色，所以對應爲1的位是黑色，對應爲0的位是白色
    **************************************************************************/
    private byte[] draw2PxPoint(Bitmap bmp) {
    //先設置一個足夠大的size，最後在用數組拷貝複製到一個精確大小的byte數組中
    int size = bmp.getWidth() * bmp.getHeight() / 8 + 1000;
    byte[] tmp = new byte[size];
    int k = 0;
    // 設置行距爲0
    tmp[k++] = 0x1B;
    tmp[k++] = 0x33;
    tmp[k++] = 0x00;
    // 居中打印
    tmp[k++] = 0x1B;
    tmp[k++] = 0x61;
    tmp[k++] = 1;
    for (int j = 0; j < bmp.getHeight() / 24f; j++) {
    tmp[k++] = 0x1B;
    tmp[k++] = 0x2A;// 0x1B 2A 表示圖片打印指令
    tmp[k++] = 33; // m=33時，選擇24點密度打印
    tmp[k++] = (byte) (bmp.getWidth() % 256); // nL
    tmp[k++] = (byte) (bmp.getWidth() / 256); // nH
    for (int i = 0; i < bmp.getWidth(); i++) {
    for (int m = 0; m < 3; m++) {
    for (int n = 0; n < 8; n++) {
    byte b = px2Byte(i, j * 24 + m * 8 + n, bmp);
    tmp[k] += tmp[k] + b;
    }
    k++;
    }
    }
    tmp[k++] = 10;// 換行
    }
    // 恢復默認行距
    tmp[k++] = 0x1B;
    tmp[k++] = 0x32;

    byte[] result = new byte[k];
    System.arraycopy(tmp, 0, result, 0, k);
    return result;
    }

  /**

  • 圖片二值化，黑色是1，白色是0
  • @param x 橫座標
  • @param y 縱座標
  • @param bit 位圖
  • @return
    */
    private byte px2Byte(int x, int y, Bitmap bit) {
    if (x < bit.getWidth() && y < bit.getHeight()) {
    byte b;
    int pixel = bit.getPixel(x, y);
    int red = (pixel & 0x00ff0000) >> 16; // 取高兩位
    int green = (pixel & 0x0000ff00) >> 8; // 取中兩位
    int blue = pixel & 0x000000ff; // 取低兩位
    int gray = RGB2Gray(red, green, blue);
    if (gray < 128) {
    b = 1;
    } else {
    b = 0;
    }
    return b;
    }
    return 0;
    }

  /**

  • 圖片灰度的轉化
    */
    private int RGB2Gray(int r, int g, int b) {
    int gray = (int) (0.29900 * r + 0.58700 * g + 0.11400 * b); // 灰度轉化公式
    return gray;
    }

  /**

  • 對圖片進行壓縮（去除透明度）
  • @param bitmapOrg
    */
    private Bitmap compressPic(Bitmap bitmapOrg) {
    // 獲取這個圖片的寬和高
    int width = bitmapOrg.getWidth();
    int height = bitmapOrg.getHeight();
    // 定義預轉換成的圖片的寬度和高度
    int newWidth = IMAGE_SIZE;
    int newHeight = IMAGE_SIZE;
    Bitmap targetBmp = Bitmap.createBitmap(newWidth, newHeight, Bitmap.Config.ARGB_8888);
    Canvas targetCanvas = new Canvas(targetBmp);
    targetCanvas.drawColor(0xffffffff);
    targetCanvas.drawBitmap(bitmapOrg, new Rect(0, 0, width, height), new Rect(0, 0, newWidth, newHeight), null);
    return targetBmp;
    }

  public static void printTest(BluetoothSocket bluetoothSocket, Bitmap bitmap) {

   try {
       PrintUtil pUtil = new PrintUtil(bluetoothSocket.getOutputStream(), "GBK");
       // 店鋪名 居中 放大
       pUtil.printAlignment(1);
       pUtil.printLargeText("廣州德勝");
       pUtil.printLine();
       pUtil.printAlignment(0);
       pUtil.printLine();
  
       pUtil.printTwoColumn("時間:", myTime);
       pUtil.printLine();
  
       pUtil.printTwoColumn("訂單號:", System.currentTimeMillis() + "");
       pUtil.printLine();
  
       pUtil.printTwoColumn("付款人:", "VitaminChen");
       pUtil.printLine();
  
       // 分隔線
       pUtil.printDashLine();
       pUtil.printLine();
  
       //打印商品列表
       pUtil.printText("商品");
       pUtil.printTabSpace(2);
       pUtil.printText("數量");
       pUtil.printTabSpace(1);
       pUtil.printText("    單價");
       pUtil.printLine();
  
       pUtil.printThreeColumn("iphone6", "1", "4999.00");
       pUtil.printThreeColumn("測試測試", "1", "4999.00");
  
       pUtil.printDashLine();
       pUtil.printLine();
  
       pUtil.printTwoColumn("訂單金額:", "9998.00");
       pUtil.printLine();
  
       pUtil.printTwoColumn("實收金額:", "10000.00");
       pUtil.printLine();
  
       pUtil.printTwoColumn("找零:", "2.00");
       pUtil.printLine();
  
       pUtil.printDashLine();
       //打印圖片
      // pUtil.printBitmap(bitmap);
  
       pUtil.printLine(4);
  
   } catch (IOException e) {
  
   }
  

  }

  private void getTime() {
  final Calendar c = Calendar.getInstance();
  int year = c.get(Calendar.YEAR);
  int month = c.get(Calendar.MONTH) + 1;
  int day = c.get(Calendar.DATE);
  int hour = c.get(Calendar.HOUR);
  int minute = c.get(Calendar.MINUTE);
  if (month > 9) {
  myTime = year + “-” + month + “-” + day;
  } else {
  if (day > 9) {
  myTime = year + “-” + “0” + month + “-” + day;
  } else {
  myTime = year + “-” + “0” + month + “-” + “0” + day;
  }

   }
  

  }
  }

第二步 ：還有一個檢測藍牙是否連接的工具類

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothClass;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.UUID;

public class BluetoothUtil {

/**
 * 藍牙是否打開
 */
public static boolean isBluetoothOn() {
	BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
	if (mBluetoothAdapter != null)
		// 藍牙已打開
		if (mBluetoothAdapter.isEnabled())
			return true;

	return false;
}

/**
 * 獲取所有已配對的設備
 */
public static List<BluetoothDevice> getPairedDevices() {
	List deviceList = new ArrayList<>();
	Set<BluetoothDevice> pairedDevices = BluetoothAdapter.getDefaultAdapter().getBondedDevices();
	if (pairedDevices.size() > 0) {
		for (BluetoothDevice device : pairedDevices) {
			deviceList.add(device);
		}
	}
	return deviceList;
}

/**
 * 獲取所有已配對的打印類設備
 */
public static List<BluetoothDevice> getPairedPrinterDevices() {
	return getSpecificDevice(BluetoothClass.Device.Major.IMAGING);
}

/**
 * 從已配對設配中，刪選出某一特定類型的設備展示
 * @param deviceClass
 * @return
 */
public static List<BluetoothDevice> getSpecificDevice(int deviceClass){
	List<BluetoothDevice> devices = BluetoothUtil.getPairedDevices();
	List<BluetoothDevice> printerDevices = new ArrayList<>();

	for (BluetoothDevice device : devices) {
		BluetoothClass klass = device.getBluetoothClass();
		// 關於藍牙設備分類參考 http://stackoverflow.com/q/23273355/4242112
		if (klass.getMajorDeviceClass() == deviceClass)
			printerDevices.add(device);
	}

	return printerDevices;
}

/**
 * 彈出系統對話框，請求打開藍牙
 */
public static void openBluetooth(Activity activity) {
	Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
	activity.startActivityForResult(enableBtIntent, 666);
}

public static BluetoothSocket connectDevice(BluetoothDevice device) {
	BluetoothSocket socket = null;
	try {
		socket = device.createRfcommSocketToServiceRecord(
				UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"));
		socket.connect();
	} catch (IOException e) {
		try {
			socket.close();
		} catch (IOException closeException) {
			return null;
		}
		return null;
	}
	return socket;
}

}

第三步：創建一個基類
import android.app.ProgressDialog;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;

import com.will.bluetoothprinterdemo.utils.BluetoothUtil;

import java.io.IOException;

public abstract class BasePrintActivity extends AppCompatActivity {

String tag = getClass().getSimpleName();
private BluetoothSocket mSocket;
private BluetoothStateReceiver mBluetoothStateReceiver;
private AsyncTask mConnectTask;
private ProgressDialog mProgressDialog;

/**
 * 藍牙連接成功後回調，該方法在子線程執行，可執行耗時操作
 */
public abstract void onConnected(BluetoothSocket socket, int taskType);


/**
 * 藍牙狀態發生變化時回調
 */
public void onBluetoothStateChanged(Intent intent) {

}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    initReceiver();
}

@Override
protected void onStop() {
    cancelConnectTask();
    closeSocket();
    super.onStop();
}

protected void closeSocket() {
    if (mSocket != null) {
        try {
            mSocket.close();
        } catch (IOException e) {
            mSocket = null;
            e.printStackTrace();
        }
    }
}

protected void cancelConnectTask() {
    if (mConnectTask != null) {
        mConnectTask.cancel(true);
        mConnectTask = null;
    }
}

@Override
protected void onDestroy() {
    unregisterReceiver(mBluetoothStateReceiver);
    super.onDestroy();
}

private void initReceiver() {
    mBluetoothStateReceiver = new BluetoothStateReceiver();
    IntentFilter filter = new IntentFilter();
    filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
    registerReceiver(mBluetoothStateReceiver, filter);
}

/**
 * 檢查藍牙狀態，如果已打開，則查找已綁定設備
 *
 * @return
 */
public boolean checkBluetoothState() {
    if (BluetoothUtil.isBluetoothOn()) {
        return true;
    } else {
        BluetoothUtil.openBluetooth(this);
        return false;
    }
}

public void connectDevice(BluetoothDevice device, int taskType) {
    if (checkBluetoothState() && device != null) {
        mConnectTask = new ConnectBluetoothTask(taskType).execute(device);
    }
}


class ConnectBluetoothTask extends AsyncTask<BluetoothDevice, Integer, BluetoothSocket> {

    int mTaskType;

    public ConnectBluetoothTask(int taskType) {
        this.mTaskType = taskType;
    }

    @Override
    protected void onPreExecute() {
        showProgressDialog("請稍候...");
        super.onPreExecute();
    }

    @Override
    protected BluetoothSocket doInBackground(BluetoothDevice... params) {
        if(mSocket != null){
            try {
                mSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        mSocket = BluetoothUtil.connectDevice(params[0]);;
        onConnected(mSocket, mTaskType);
        return mSocket;
    }

    @Override
    protected void onPostExecute(BluetoothSocket socket) {
        mProgressDialog.dismiss();
        if (socket == null || !socket.isConnected()) {
            toast("連接打印機失敗");
        } else {
            toast("成功！");
        }

        super.onPostExecute(socket);
    }
}


protected void showProgressDialog(String message) {
    if (mProgressDialog == null) {
        mProgressDialog = new ProgressDialog(this);
        mProgressDialog.setCanceledOnTouchOutside(false);
        mProgressDialog.setCancelable(false);
    }
    mProgressDialog.setMessage(message);
    if (!mProgressDialog.isShowing()) {
        mProgressDialog.show();
    }
}

protected void toast(String message) {
    Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
}

/**
 * 監聽藍牙狀態變化的系統廣播
 */
class BluetoothStateReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, -1);
        switch (state) {
            case BluetoothAdapter.STATE_TURNING_ON:
                toast("藍牙已開啓");
                break;

            case BluetoothAdapter.STATE_TURNING_OFF:
                toast("藍牙已關閉");
                break;
        }
        onBluetoothStateChanged(intent);
    }
}

}

第四步：主界面代碼

package com.will.bluetoothprinterdemo.ui;

import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.provider.Settings;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.will.bluetoothprinterdemo.R;
import com.will.bluetoothprinterdemo.utils.BluetoothUtil;
import com.will.bluetoothprinterdemo.utils.PrintUtil;

import java.util.List;

public class PrinterSettingActivity extends BasePrintActivity implements View.OnClickListener{

ListView mLvPairedDevices;
Button mBtnSetting;
Button mBtnTest;
Button mBtnPrint;

DeviceListAdapter mAdapter;
int mSelectedPosition = -1;

final static int TASK_TYPE_CONNECT = 1;
final static int TASK_TYPE_PRINT = 2;

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

@Override
protected void onResume() {
    super.onResume();
    fillAdapter();
}

private void initViews() {
    mLvPairedDevices = (ListView) findViewById(R.id.lv_paired_devices);
    mBtnSetting = (Button) findViewById(R.id.btn_goto_setting);
    mBtnTest = (Button) findViewById(R.id.btn_test_conntect);
    mBtnPrint = (Button) findViewById(R.id.btn_print);

    mLvPairedDevices.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            mSelectedPosition = position;
            mAdapter.notifyDataSetChanged();
        }
    });

    mBtnSetting.setOnClickListener(this);
    mBtnTest.setOnClickListener(this);
    mBtnPrint.setOnClickListener(this);

    mAdapter = new DeviceListAdapter(this);
    mLvPairedDevices.setAdapter(mAdapter);
}

/**
 * 從所有已配對設備中找出打印設備並顯示
 */
private void fillAdapter() {
    //推薦使用 BluetoothUtil.getPairedPrinterDevices()
    List<BluetoothDevice> printerDevices = BluetoothUtil.getPairedDevices();
    mAdapter.clear();
    mAdapter.addAll(printerDevices);
    refreshButtonText(printerDevices);
}

private void refreshButtonText(List<BluetoothDevice> printerDevices) {
    if (printerDevices.size() > 0) {
        mBtnSetting.setText("配對更多設備");
    } else {
        mBtnSetting.setText("還未配對打印機，去設置");
    }
}

@Override
public void onClick(View v) {
    switch (v.getId()){
        case R.id.btn_goto_setting:
            startActivity(new Intent(Settings.ACTION_BLUETOOTH_SETTINGS));
            break;

        case R.id.btn_test_conntect:
            connectDevice(TASK_TYPE_CONNECT);
            break;

        case R.id.btn_print:
            connectDevice(TASK_TYPE_PRINT);
            break;
    }
}

private void connectDevice(int taskType){
    if(mSelectedPosition >= 0){
        BluetoothDevice device = mAdapter.getItem(mSelectedPosition);
        if(device!= null)
            super.connectDevice(device, taskType);
    }else{
        Toast.makeText(this, "還未選擇打印設備", Toast.LENGTH_SHORT).show();
    }
}

@Override
public void onConnected(BluetoothSocket socket, int taskType) {
    switch (taskType){
        case TASK_TYPE_PRINT:
            Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.test_image);
            PrintUtil.printTest(socket, bitmap);
            break;
    }
}


class DeviceListAdapter extends ArrayAdapter<BluetoothDevice> {

    public DeviceListAdapter(Context context) {
        super(context, 0);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        BluetoothDevice device = getItem(position);
        if (convertView == null) {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_bluetooth_device, parent, false);
        }

        TextView tvDeviceName = (TextView) convertView.findViewById(R.id.tv_device_name);
        CheckBox cbDevice = (CheckBox) convertView.findViewById(R.id.cb_device);

        tvDeviceName.setText(device.getName());

        cbDevice.setChecked(position == mSelectedPosition);

        return convertView;
    }
}

}

第五步：主界面佈局
activity_printer_setting.xml

<?xml version="1.0" encoding="utf-8"?>

<TextView
    android:layout_width="match_parent"
    android:layout_height="48dp"
    android:background="@color/colorGrayTertiary"
    android:gravity="center_vertical"
    android:paddingLeft="16dp"
    android:text="選擇一個已配對的打印設備"
    android:textColor="@color/textColorSecondary"
    android:textSize="14sp" />

<ListView
    android:id="@+id/lv_paired_devices"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:background="@color/colorWhite"
    android:choiceMode="singleChoice"
    android:divider="@android:drawable/divider_horizontal_bright" />

<Button
    android:id="@+id/btn_goto_setting"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="@dimen/common_margin"
    android:layout_marginRight="@dimen/common_margin"
    android:layout_marginTop="@dimen/common_margin"
    android:text="還未配對打印機，去設置" />

<Button
    android:id="@+id/btn_test_conntect"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="@dimen/common_margin"
    android:layout_marginRight="@dimen/common_margin"
    android:layout_marginTop="@dimen/common_margin"
    android:text="測試打印機連接" />

<Button
    android:id="@+id/btn_print"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginLeft="@dimen/common_margin"
    android:layout_marginRight="@dimen/common_margin"
    android:layout_marginTop="@dimen/common_margin"
    android:text="打印"
    android:layout_marginBottom="@dimen/common_margin"/>

佈局二：

<?xml version="1.0" encoding="utf-8"?>

<TextView
    android:id="@+id/tv_device_name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:text="藍牙打印機"
    android:textColor="@color/textColorPrimary"
    android:textSize="14sp" />

<android.support.v7.widget.AppCompatCheckBox
    android:id="@+id/cb_device"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:clickable="false"
    android:focusable="false"
    android:focusableInTouchMode="false"
    android:textSize="14sp" />