android获取usb权限
时间: 2023-10-10 14:13:02 浏览: 44
要在 Android 应用程序中获取 USB 权限,需要在应用程序清单文件中声明相应的 USB 权限。在清单文件中,添加以下代码即可:
```xml
<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />
```
接下来,在应用程序中,需要注册一个 BroadcastReceiver,当 USB 设备连接或断开连接时,会收到广播。在 BroadcastReceiver 中,需要请求 USB 权限,以便与 USB 设备进行通信。以下是示例代码:
```java
private static final String ACTION_USB_PERMISSION = "com.example.USB_PERMISSION";
private UsbManager usbManager;
private UsbDevice device;
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if(device != null){
// 在此处进行与 USB 设备的通信
}
}
else {
Log.d(TAG, "permission denied for device " + device);
}
}
}
}
};
public void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(usbReceiver, filter);
// 获取 USB 设备列表
usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
if (!deviceList.isEmpty()) {
// 选择一个 USB 设备
device = deviceList.values().iterator().next();
// 请求 USB 权限
PendingIntent permissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
usbManager.requestPermission(device, permissionIntent);
}
}
public void onPause() {
super.onPause();
unregisterReceiver(usbReceiver);
}
```
在上面的代码中,我们注册了一个 BroadcastReceiver,并在 onResume() 方法中获取 USB 设备列表,选择一个设备,然后请求 USB 权限。当用户授权 USB 权限时,我们就可以在 BroadcastReceiver 中进行与 USB 设备的通信了。