android蓝牙发送图片demo

以下是一个简单的Android蓝牙发送图片的Demo，仅供参考：

1. 首先在AndroidManifest.xml文件中添加蓝牙权限：

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

2. 在需要发送图片的Activity中，创建蓝牙Socket连接：

private BluetoothAdapter bluetoothAdapter;
private BluetoothDevice bluetoothDevice;
private BluetoothSocket bluetoothSocket;

private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

private void connectToDevice() {
    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    bluetoothDevice = bluetoothAdapter.getRemoteDevice("MAC_ADDRESS_OF_REMOTE_DEVICE");
    try {
        bluetoothSocket = bluetoothDevice.createRfcommSocketToServiceRecord(MY_UUID);
        bluetoothSocket.connect();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

其中，MAC_ADDRESS_OF_REMOTE_DEVICE需要替换为远程设备的MAC地址。

3. 发送图片数据：

private void sendImage() {
    OutputStream outputStream;
    try {
        outputStream = bluetoothSocket.getOutputStream();
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.image);
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream);
        byte[] byteArray = byteArrayOutputStream.toByteArray();
        outputStream.write(byteArray);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

其中，R.drawable.image需要替换为实际的图片资源ID。

4. 完整代码：

public class MainActivity extends AppCompatActivity {

    private BluetoothAdapter bluetoothAdapter;
    private BluetoothDevice bluetoothDevice;
    private BluetoothSocket bluetoothSocket;

    private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

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

        connectToDevice();
        sendImage();
    }

    private void connectToDevice() {
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        bluetoothDevice = bluetoothAdapter.getRemoteDevice("MAC_ADDRESS_OF_REMOTE_DEVICE");
        try {
            bluetoothSocket = bluetoothDevice.createRfcommSocketToServiceRecord(MY_UUID);
            bluetoothSocket.connect();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void sendImage() {
        OutputStream outputStream;
        try {
            outputStream = bluetoothSocket.getOutputStream();
            Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.image);
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream);
            byte[] byteArray = byteArrayOutputStream.toByteArray();
            outputStream.write(byteArray);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

需要注意的是，由于蓝牙传输的数据量比较大，需要使用异步线程进行发送，避免阻塞主线程。此外，需要确保远程设备已经开启蓝牙，并且已经配对。