蓝牙传输在安卓应用开发中是一种常见的数据传输方式。它可以用于不同设备之间的数据交换，如音频、图片、视频、文本等。这里我们将介绍在安卓应用中如何实现蓝牙传输。
首先，在使用蓝牙传输之前，我们需要获取蓝牙设备的权限。这可以通过以下代码来实现：
```java
private void requestBluetoothPermission() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH)
== PackageManager.PERMISSION_GRANTED) {
return;
}
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH}, REQUEST_ENABLE_BT);
}
```
接下来启用蓝牙，可以使用以下代码：
```java
private void enableBluetooth() {
if (!bluetoothAdapter.isEnabled()) {
Intent enableBTIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBTIntent, REQUEST_ENABLE_BT);
}
}
```
接着搜索附近的蓝牙设备：
```java
bluetoothAdapter.startDiscovery();
```
当发现一个蓝牙设备时，可以将其加入到列表中：
```java
private final BroadcastReceiver bluetoothReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
if (device != null) {
String name = device.getName();
String macAddress = device.getAddress();
deviceList.add(new BluetoothDeviceItem(name, macAddress));
deviceListAdapter.notifyDataSetChanged();
}
}
}
};
```
在列表中选择一个设备时，可以打开一个新的Activity，并将被选中的设备传给它：
```java
public void onItemClick(AdapterView parent, View view, int position, long id) {
BluetoothDeviceItem deviceItem = deviceList.get(position);
Intent intent = new Intent(this, BluetoothChatActivity.class);
intent.putExtra(EXTRA_DEVICE, deviceItem);
startActivity(intent);
}
```
最后，在BluetoothChatActivity中，可以使用BluetoothSocket类进行数据的传输。设备之间的数据传输可以通过流来实现：
```java
private class ConnectThread extends Thread {
private BluetoothSocket socket;
private final BluetoothDevice device;
public ConnectThread(BluetoothDevice device) {
this.device = device;
}
public void run() {
try {
socket = device.createRfcommSocketToServiceRecord(MY_UUID);
socket.connect();
sendReceiveThread = new SendReceiveThread(socket);
sendReceiveThread.start();
} catch (IOException e) {
e.printStackTrace();
try {
socket.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
private class SendReceiveThread extends Thread {
private final BluetoothSocket socket;
private final InputStream inputStream;
private final OutputStream outputStream;
public SendReceiveThread(BluetoothSocket socket) {
this.socket = socket;
InputStream tempIn = null;
OutputStream tempOut = null;
try {
tempIn = socket.getInputStream();
tempOut = socket.getOutputStream();
} catch (IOException e) {
e.printStackTrace();
}
inputStream = tempIn;
outputStream = tempOut;
}
public void run() {
byte[] buffer = new byte[1024];
int bytes;
while (true) {
try {
bytes = inputStream.read(buffer);
handler.obtainMessage(MESSAGE_READ, bytes, -1, buffer).sendToTarget();
} catch (IOException e) {
e.printStackTrace();
break;
}
}
}
public void write(byte[] bytes) {
try {
outputStream.write(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
}
```
以上代码只是蓝牙传输的基本实现，具体的应用场景还需根据实际情况进行更改与调整。
