藍牙鏈接：
Android做藍牙開發(fā)最大的也是唯一的一個坑就是你要分清楚傳統(tǒng)藍牙和低功耗藍牙（Bluetooth Low Energy），他們的API不一樣，也不通用。
區(qū)別他們也很容易：低功耗藍牙顧名思義，用于功耗低的設(shè)備，比如各種智能手環(huán)、心率儀。你可以直接查閱官方文檔，我認為官方文檔是最好的資料，里面有很詳細的例子，傳統(tǒng)藍牙有中文翻譯，低功耗藍牙則沒有
android中藍牙的打開、搜索主要分為以下幾步。
1.在AndroidManifest.xml中添加藍牙權(quán)限。
<!-- 管理藍牙設(shè)備的權(quán)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"/>
<!-- 在sd卡中創(chuàng)建與刪除文件權(quán)限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"
? ? tools:ignore="ProtectedPermissions"/>
<!-- 向SD卡寫入數(shù)據(jù)權(quán)限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CLEAR_APP_CACHE"
? ? tools:ignore="ProtectedPermissions" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
2.啟動藍牙
private?boolean?openBtDevice()?{?
//?獲得藍牙匹配器?
mBluetoothAdapter?=?BluetoothAdapter.getDefaultAdapter();?
//?藍牙設(shè)備不被支持?
if?(mBluetoothAdapter?==?null)?{?
Log.e(TAG,?"Your?device?is?not?support?Bluetooth!");?
Toast.makeText(this,?"該設(shè)備沒有藍牙設(shè)備",?Toast.LENGTH_LONG).show();?
return?false;?
}?
//?使能藍牙設(shè)備?
if?(!mBluetoothAdapter.isEnabled())?{?
//?隱式Intent?
Intent?enableBtIntent?=?new?Intent(?
BluetoothAdapter.ACTION_REQUEST_ENABLE);?
startActivityForResult(enableBtIntent,?REQUES_BT_ENABLE_CODE);?
}?else?{?
Toast.makeText(this,?"藍牙打開成功！",?Toast.LENGTH_SHORT).show();?
}?
return?true;?
}?
//?當startActivityForResult啟動的?畫面結(jié)束的時候，該方法被回調(diào)?
@Override?
protected?void?onActivityResult(int?requestCode,?int?resultCode,?Intent?data)?{?
if?(requestCode?==?REQUES_BT_ENABLE_CODE?&&?resultCode?==?RESULT_OK)?{?
Toast.makeText(this,?"藍牙打開成功！",?Toast.LENGTH_SHORT).show();?
}?
}
3.搜索藍牙
已經(jīng)配對過的藍牙設(shè)備
private?void?findBtDevice()?{?
Set?pairedDevices?=?mBluetoothAdapter.getBondedDevices();?
if?(pairedDevices.size()?>?0)?{?
for?(BluetoothDevice?device?:?pairedDevices)?{?
if?(mDeviceList.contains(device))?{?
return;?
}?
mArrayAdapter.add(device.getName()?+?"\n"?+?device.getAddress());?
mDeviceList.add(device);?
}?
}?
adapter.notifyDataSetChanged();?
}
動態(tài)注冊廣播搜索藍牙
IntentFilter?filter?=?new?IntentFilter(BluetoothDevice.ACTION_FOUND);?
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);?
registerReceiver(mReceiver,?filter);?
//廣播用于動態(tài)的添加搜索到的藍牙到ListView中顯示?
private?final?BroadcastReceiver?mReceiver?=?new?BroadcastReceiver()?{?
@Override?
public?void?onReceive(Context?context,?Intent?intent)?{?
//?TODO?Auto-generated?method?stub?
String?action?=?intent.getAction();?
if?(BluetoothDevice.ACTION_FOUND.equals(action))?{?
//發(fā)現(xiàn)的藍牙設(shè)備?
BluetoothDevice?device?=?intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//發(fā)現(xiàn)的藍牙設(shè)備已存在則跳過?
if?(mDeviceList.contains(device))?{?
return;?
}?
//添加發(fā)現(xiàn)的藍牙設(shè)備?
mArrayAdapter.add(device.getName()?+?"\n"?+?device.getAddress());?
mDeviceList.add(device);?
//更新到ListView?
adapter.notifyDataSetChanged();?
}?else?if?(BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action))?{?
//搜索結(jié)束，關(guān)閉滾動條?
setProgressBarIndeterminateVisibility(false);?
}?
}?
};
//下面是一個簡單的藍牙搜索顯示藍牙示例//
首先新建工程、接著在在AndroidManifest.xml中添加藍牙權(quán)限。
編寫布局文件
android:layout_width="match_parent"?
android:layout_height="match_parent"?
android:orientation="vertical"?>?
android:id="@+id/XianShi"?
android:layout_width="match_parent"?
android:layout_height="wrap_content"?
android:gravity="center"?
android:text="無內(nèi)容"?/>?
android:layout_width="match_parent"?
android:layout_height="wrap_content"?
android:orientation="horizontal"?>?
android:id="@+id/SendText"?
android:layout_width="wrap_content"?
android:layout_height="wrap_content"?
android:layout_weight="1.0"?
android:hint="請輸入"?/>?
android:layout_width="wrap_content"?
android:layout_height="wrap_content"?
android:onClick="MySend"?
android:text="發(fā)送"?/>?
android:id="@+id/FindBt"?
android:layout_width="match_parent"?
android:layout_height="wrap_content"?
android:text="搜索"?/>?
android:layout_width="match_parent"?
android:layout_height="wrap_content"?
android:gravity="center"?
android:text="藍牙列表"?/>?
android:id="@+id/DeviceList"?
android:layout_width="match_parent"?
android:layout_height="wrap_content"?>?
/編寫源代碼//
public?class?MainActivity?extends?Activity?{?
private?EditText?mET;???//發(fā)送內(nèi)容，本示例未用到?
private?Button?MyScan;??//搜索按鈕?
private?TextView?MyMessage;??//顯示內(nèi)容，本示例未用到?
private?ListView?MyBtList;???//顯示藍牙列表的ListView?
private?BluetoothAdapter?mBluetoothAdapter;??//藍牙適配器?
private?ArrayAdapter?adapter;????????//Listview使用的適配器?
private?ArrayList?mArrayAdapter?=?new?ArrayList();??//保存ListView顯示藍牙設(shè)備的內(nèi)容?
private?ArrayList?mDeviceList?=?new?ArrayList();??//保存查找的藍牙設(shè)備，避免在ListView重復(fù)顯示?
private?static?final?String?TAG?=?"MyBluetooth";???//調(diào)試用?
private?static?final?int?REQUES_BT_ENABLE_CODE?=?0x1002;???//?藍牙使能請求碼?
@Override?
protected?void?onCreate(Bundle?savedInstanceState)?{?
super.onCreate(savedInstanceState);?
requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);???//請求顯示滾動條?
setContentView(R.layout.activity_main);?
//UI注冊?
mET?=?(EditText)?findViewById(R.id.SendText);?
MyScan?=?(Button)?findViewById(R.id.FindBt);?
MyMessage?=?(TextView)?findViewById(R.id.XianShi);?
MyBtList?=?(ListView)?findViewById(R.id.DeviceList);?
//ListView添加適配器?
adapter?=?new?ArrayAdapter(this,?
android.R.layout.simple_list_item_1,?mArrayAdapter);?
MyBtList.setAdapter(adapter);?
openBtDevice();???//打開藍牙?
//搜索藍牙按鈕點擊事件?
MyScan.setOnClickListener(new?MyScanClick());?
IntentFilter?filter?=?new?IntentFilter(BluetoothDevice.ACTION_FOUND);?
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);?
//?動態(tài)注冊廣播接收器?
//?用來接收掃描到的設(shè)備信息?
registerReceiver(mReceiver,?filter);?
}?
//搜索藍牙按鈕點擊事件?
private?class?MyScanClick?implements?OnClickListener?{?
@Override?
public?void?onClick(View?v)?{?
//?TODO?Auto-generated?method?stub?
if?(!mBluetoothAdapter.isDiscovering())?{?
findBtDevice();??//打開藍牙?
mBluetoothAdapter.startDiscovery();??//開始搜索?
setProgressBarIndeterminateVisibility(true);??//顯示滾動條?
}?
}?
}?
//廣播用于動態(tài)的添加搜索到的藍牙到ListView中顯示?
private?final?BroadcastReceiver?mReceiver?=?new?BroadcastReceiver()?{?
@Override?
public?void?onReceive(Context?context,?Intent?intent)?{?
//?TODO?Auto-generated?method?stub?
String?action?=?intent.getAction();?
if?(BluetoothDevice.ACTION_FOUND.equals(action))?{?
//發(fā)現(xiàn)的藍牙設(shè)備?
BluetoothDevice?device?=?intent?
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);?
//發(fā)現(xiàn)的藍牙設(shè)備已存在則跳過?
if?(mDeviceList.contains(device))?{?
return;?
}?
//添加發(fā)現(xiàn)的藍牙設(shè)備?
mArrayAdapter?
.add(device.getName()?+?"\n"?+?device.getAddress());?
mDeviceList.add(device);?
//更新到ListView?
adapter.notifyDataSetChanged();?
}?else?if?(BluetoothAdapter.ACTION_DISCOVERY_FINISHED?
.equals(action))?{?
//搜索結(jié)束，關(guān)閉滾動條?
setProgressBarIndeterminateVisibility(false);?
}?
}?
};?
//之前已經(jīng)配對的藍牙，添加到ListView?
private?void?findBtDevice()?{?
Set?pairedDevices?=?mBluetoothAdapter?
.getBondedDevices();?
if?(pairedDevices.size()?>?0)?{?
for?(BluetoothDevice?device?:?pairedDevices)?{?
if?(mDeviceList.contains(device))?{?
return;?
}?
mArrayAdapter?
.add(device.getName()?+?"\n"?+?device.getAddress());?
mDeviceList.add(device);?
}?
}?
adapter.notifyDataSetChanged();?
}?
//打開藍牙?
private?boolean?openBtDevice()?{?
//?獲得藍牙匹配器?
mBluetoothAdapter?=?BluetoothAdapter.getDefaultAdapter();?
//?藍牙設(shè)備不被支持?
if?(mBluetoothAdapter?==?null)?{?
Log.e(TAG,?"Your?device?is?not?support?Bluetooth!");?
Toast.makeText(this,?"該設(shè)備沒有藍牙設(shè)備",?Toast.LENGTH_LONG).show();?
return?false;?
}?
//?使能藍牙設(shè)備?
if?(!mBluetoothAdapter.isEnabled())?{?
//?隱式Intent?
Intent?enableBtIntent?=?new?Intent(?
BluetoothAdapter.ACTION_REQUEST_ENABLE);?
startActivityForResult(enableBtIntent,?REQUES_BT_ENABLE_CODE);?
}?else?{?
Toast.makeText(this,?"藍牙打開成功！",?Toast.LENGTH_SHORT).show();?
}?
return?true;?
}?
//?當startActivityForResult啟動的?畫面結(jié)束的時候，該方法被回調(diào)?
@Override?
protected?void?onActivityResult(int?requestCode,?int?resultCode,?Intent?data)?{?
if?(requestCode?==?REQUES_BT_ENABLE_CODE?&&?resultCode?==?RESULT_OK)?{?
Toast.makeText(this,?"藍牙打開成功！",?Toast.LENGTH_SHORT).show();?
}?
}?
}?
藍牙打印
鏈接打印機后，執(zhí)行以下代碼：打印文字，格式類似于外賣單：
public class PrintTextActivityextends Activity {
List>listData =new ArrayList>();
private EditTextet_input;
private CheckBoxcheckBoxAuto;
private Buttonbt_print;
private Threadautoprint_Thread;
int times =500;// Automatic print time interval
? boolean isPrint =true;
Stringmessage="";
@Override
? protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
? ? ? super.onCreate(savedInstanceState);
setContentView(R.layout.activity_print_text);
isPrint =true;
et_input = (EditText) findViewById(R.id.et_input_1);
//et_input.setText("Printing test\n");
? ? ? bt_print = (Button) findViewById(R.id.bt_print);
bt_print.setOnClickListener(new OnClickListener() {
@Override
? ? ? ? public void onClick(View v) {
message=et_input.getText().toString().trim();
try {
byte[] send=message.getBytes("GBK");
PrintService.pl.write(send);
}catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
PrintService.pl.printText("\n");
PrintService.pl.write(new byte[]{0x1b,0x61,0x01});
//PrintService.pl.write(new byte[] { 0x1d, 0x0c });
? ? ? ? ? ? PrintService.pl.write(new byte[] {0x1b,0x21,0x11 });
PrintService.pl.printText("xxx");
//修改文字模式為加粗模式
? ? ? ? ? ? PrintService.pl.write(new byte[]{0X1b,0x45,0x01});
PrintService.pl.write(new byte[]{0x1d,0x21,0x03});
PrintService.pl.printText("\n");
//修改文字加粗模式為0
? ? ? ? ? ? PrintService.pl.write(new byte[]{0x1b,0x21,0x00});
//文字居中
? ? ? ? ? ? PrintService.pl.write(new byte[]{0x1b,0x61,0x01});
PrintService.pl.printText("已支付");
PrintService.pl.printText("\n");
PrintService.pl.printText("下單時間:10—24"+"\t"+"11:15");
PrintService.pl.printText("\n");
PrintService.pl.printText("貨號"+"\t"+"\t"+"\t"+"\t"+"\t"+"數(shù)量"+"\t"+"價格");
PrintService.pl.printText("-----------------------------");
PrintService.pl.printText("\n");
PrintService.pl.printText("GP-3120TU"+"\t"+"\t"+"\t"+"\t"+"X1"+"\t"+"\t"+"286");
PrintService.pl.printText("\n");
PrintService.pl.printText("GP-1124D"+"\t"+"\t"+"\t"+"\t"+"X2"+"\t"+"\t"+"560");
PrintService.pl.printText("\n");
PrintService.pl.printText("GP-1124T"+"\t"+"\t"+"\t"+"\t"+"X1"+"\t"+"\t"+"698");
PrintService.pl.printText("\n");
PrintService.pl.printText("-----------------------------");
PrintService.pl.printText("\n");
PrintService.pl.printText("實收" +"\t" +"\t" +"\t" +"\t" +"￥" +"\t" +"1603");
PrintService.pl.printText("\n");
PrintService.pl.printText("找零" +"\t" +"\t" +"\t" +"\t" +"￥" +"\t" +"2");
PrintService.pl.printText("\n");
PrintService.pl.printText("-----------------------------");
PrintService.pl.printText("\n");
PrintService.pl.write(new byte[]{0x1b,0x61,0x01});
PrintService.pl.printText("請保管好購物憑證");
PrintService.pl.printText("\n");
PrintService.pl.write(new byte[]{0x1b,0x61,0x01});
PrintService.pl.printText("多謝惠顧");
}
});
checkBoxAuto = (CheckBox) findViewById(R.id.checkBoxAuto);
// Auto Print
? ? ? autoprint_Thread =new Thread() {
public void run() {
while (isPrint) {
if (checkBoxAuto.isChecked()) {
String message =et_input.getText().toString();
PrintService.pl.printText(message);
PrintService.pl.write(new byte[] {0x1d,0x0c });
try {
Thread.sleep(times);
}catch (InterruptedException e) {
// TODO Auto-generated catch block
? ? ? ? ? ? ? ? ? ? e.printStackTrace();
}
}
}
}
};
autoprint_Thread.start();
//? ? et_input.addTextChangedListener(textWatcher);
? }
@Override
? public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
Resources res = getResources();
String[] cmdStr = res.getStringArray(R.array.cmd);
for (int i =0; i < cmdStr.length; i++) {
String[] cmdArray = cmdStr[i].split(",");
if (cmdArray.length ==2) {
Map map =new HashMap();
map.put("title", cmdArray[0]);
map.put("description", cmdArray[1]);
menu.add(0, i, i, cmdArray[0]);
listData.add(map);
}
}
return true;
}
@Override
? public boolean onOptionsItemSelected(android.view.MenuItem item) {
Map map =listData.get(item.getItemId());
String cmd = map.get("description").toString();
byte[] bt = PrintCmdActivity.hexStringToBytes(cmd);
PrintService.pl.write(bt);
Toast toast = Toast.makeText(this,"Send Success", Toast.LENGTH_SHORT);
toast.show();
return false;
}
@Override
? protected void onStop() {
// TODO Auto-generated method stub
? ? ? isPrint =false;
super.onStop();
}
private static Bitmap resizeImage(Bitmap bitmap,int w,int h) {
Bitmap BitmapOrg = bitmap;
int width = BitmapOrg.getWidth();
int height = BitmapOrg.getHeight();
if (width > w) {
float scaleWidth = ((float) w) / width;
float scaleHeight = ((float) h) / height +24;
Matrix matrix =new Matrix();
matrix.postScale(scaleWidth, scaleWidth);
Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg,0,0, width,
height, matrix,true);
return resizedBitmap;
}else {
Bitmap resizedBitmap = Bitmap.createBitmap(w, height +24,
Config.RGB_565);
Canvas canvas =new Canvas(resizedBitmap);
Paint paint =new Paint();
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(bitmap, (w - width) /2,0, paint);
return resizedBitmap;
}
}
}
