蓝牙打印开发代码示例（日拱一卒，有点进步，UUID仍报错）
package com.lingrui.btprint; import android.Manifest; import android.app.AlertDialog; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothSocket; import android.content.DialogInterface; import android.content.Intent; import android.content.pm.PackageManager; import android.os.Build; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.CheckBox; import android.widget.Toast; import androidx.activity.EdgeToEdge; import androidx.activity.result.ActivityResult; import androidx.activity.result.ActivityResultCallback; import androidx.activity.result.ActivityResultLauncher; import androidx.activity.result.contract.ActivityResultContracts; import androidx.annotation.RequiresApi; import androidx.appcompat.app.AppCompatActivity; import androidx.core.app.ActivityCompat; import androidx.core.content.ContextCompat; import java.io.IOException; import java.io.OutputStream; import java.util.Set; import java.util.UUID; public class MainActivity extends AppCompatActivity implements View.OnClickListener { public static String MY_UUID = "DC:0D:30:D6:0F:50"; /** * 代表本地蓝牙适配器（蓝牙无线电）。BluetoothAdapter是所有蓝牙交互的入口。 * 使用这个你可以发现其他蓝牙设备，查询已配对的设备列表， * 使用一个已知的MAC地址来实例化一个BluetoothDevice， * 以及创建一个BluetoothServerSocket来为监听与其他设备的通信。 */ private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); /** * 代表一个远程蓝牙设备，使用这个来请求一个与远程设备的BluetoothSocket连接， * 或者查询关于设备名称、地址、类和连接状态等设备信息。 */ private BluetoothDevice mBluetoothDevice = null; /** * 代表一个蓝牙socket的接口（和TCP Socket类似）。这是一个连接点， * 它允许一个应用与其他蓝牙设备通过InputStream和OutputStream交换数据。 */ private BluetoothSocket mBluetoothSocket = null; BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); public ActivityResultLauncher<Intent> register; ActivityResultLauncher<Intent> startBlueTooth = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<ActivityResult>() { @Override public void onActivityResult(ActivityResult result) { if (result==null) { Log.e("error:","打开失败"); } else { Log.e("DEBUG:","6666666666666666666666666666666"); if (result.getResultCode() == RESULT_CANCELED) { Log.d("debug", "用户取消"); } } } }); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); EdgeToEdge.enable(this); setContentView(R.layout.activity_main); //点击蓝牙按钮 Button btBlt = findViewById(R.id.bt_blt); btBlt.setOnClickListener(this); CheckBox ck_1 = findViewById(R.id.ck_1); } @Override public void onClick(View v) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) { checkConnectPermission(); } Toast.makeText(getApplicationContext(), "蓝牙TEST", Toast.LENGTH_SHORT).show(); try { Log.d("debug", "点击打开蓝牙按钮"); mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); // 如果设备不支持蓝牙 if (mBluetoothAdapter == null) { Log.d("debug", "设备不支持蓝牙"); return; } // 设备支持蓝牙功能，启动蓝牙 if (!mBluetoothAdapter.isEnabled()) { register.launch(new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)); Log.d("debug", "启动蓝牙"); } //打开蓝牙 if (ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) { // TODO: Consider calling // ActivityCompat#requestPermissions // here to request the missing permissions, and then overriding // public void onRequestPermissionsResult(int requestCode, String[] permissions, // int[] grantResults) // to handle the case where the user grants the permission. See the documentation // for ActivityCompat#requestPermissions for more details. return; } boolean enable = mBluetoothAdapter.enable(); Log.d("debug", "蓝牙开启状态:"+String.valueOf(enable)); //取得蓝牙开启状态 //一旦蓝牙已经打开，我们可以使用蓝牙适配器来搜索附近的蓝牙设备 if (ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) != PackageManager.PERMISSION_GRANTED) { // TODO: Consider calling // ActivityCompat#requestPermissions return; } Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices(); //getBondedDevices 方法返回已经配对的蓝牙设备的集合。通过遍历集合，可以获取设备的名称和地址等信息 for (BluetoothDevice device : pairedDevices) { String deviceName = device.getName(); String deviceAddress = device.getAddress(); // 处理找到的设备信息 Log.d("debug", deviceName); Log.d("debug", deviceAddress); mBluetoothDevice = device; } Log.d("debug", "步骤四：连接蓝牙设备"); Toast.makeText(getApplicationContext(), "蓝牙TEST", Toast.LENGTH_SHORT).show(); /*步骤四：连接蓝牙设备 在搜索到蓝牙设备后，我们需要选择一个设备进行连接*/ BluetoothSocket socket = mBluetoothDevice.createRfcommSocketToServiceRecord(UUID.fromString(MY_UUID)); Log.d("debug", MY_UUID); socket.connect(); //连接成功后，我们可以通过蓝牙连接发送打印指令给蓝牙标签打印机。 OutputStream outputStream = socket.getOutputStream(); }catch (IllegalStateException | IOException e) { Log.d("debug", e.getMessage()); Toast.makeText(getApplicationContext(), "蓝牙打开失败："+"\n"+e.getMessage(), Toast.LENGTH_SHORT).show(); } } public void showPermissionDialog() { AlertDialog.Builder builder = new AlertDialog.Builder(this, android.R.style.Theme_DeviceDefault_Light_Dialog_NoActionBar_MinWidth); builder.setMessage("需要读SD卡权限，用来获取照片\n需要获取手机状态权限，用来获取设备号\n需要获取联系人权限，用来..."); builder.setTitle("权限说明"); builder.setCancelable(true); builder.setPositiveButton("申请", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { ; } }); builder.show(); } @RequiresApi(api = Build.VERSION_CODES.S) private void checkConnectPermission() { if (ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.BLUETOOTH_CONNECT) == PackageManager.PERMISSION_DENIED) { Log.i("MES", "SUCCESS"); ActivityCompat.requestPermissions(MainActivity.this, new String[] {android.Manifest.permission.BLUETOOTH_CONNECT} ,2); } if (ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_DENIED) { Log.i("MES", "SUCCESS"); ActivityCompat.requestPermissions(MainActivity.this, new String[] {android.Manifest.permission.ACCESS_FINE_LOCATION} ,2); } if (ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.BLUETOOTH_SCAN) == PackageManager.PERMISSION_DENIED) { Log.i("MES", "SUCCESS"); ActivityCompat.requestPermissions(MainActivity.this, new String[] {android.Manifest.permission.BLUETOOTH_SCAN} ,2); } } }
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:background="#E8E8E8"> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal"> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:id="@+id/tv_1" android:text="物料名称" android:textColor="@color/black" /> <EditText android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:id="@+id/et_1" android:text="物料名称" android:textColor="@color/black" /> </LinearLayout> <Button android:id="@+id/bt_blt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="打开蓝牙"/> <Button android:id="@+id/bt_blt2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="关闭蓝牙"/> <TextView android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:id="@+id/tv_2" android:text="物料名称" android:textColor="@color/black" /> <CheckBox android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/ck_1" android:text="测试"/> </LinearLayout>
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools"> <uses-permission android:name="android.permission.BLUETOOTH" /> <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" /><!--this的检查项--> <uses-permission android:name="android.permission.BLUETOOTH_SCAN"/> <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" /> <!-- 以上两行必须同时添加，不然报错 --> <uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE"/> <application android:allowBackup="true" android:dataExtractionRules="@xml/data_extraction_rules" android:fullBackupContent="@xml/backup_rules" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/Theme.BtPrint" tools:targetApi="31"> <activity android:name=".MainActivity" android:exported="true"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
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