android app弹出访问usb设备
时间: 2023-11-23 07:06:49 浏览: 55
要在Android应用程序中访问USB设备,您需要执行以下步骤:
1. 在AndroidManifest.xml文件中添加以下权限:
```
<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />
```
2. 检测连接的USB设备:
```
UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> usbDevices = usbManager.getDeviceList();
if (!usbDevices.isEmpty()) {
// USB设备已连接
UsbDevice device = usbDevices.get(deviceName);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
usbManager.requestPermission(device, pendingIntent);
} else {
// 没有连接的USB设备
}
```
3. 处理用户授权:
```
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
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) {
// 授权成功,可以开始访问USB设备
}
} else {
// 用户拒绝了授权请求
}
}
}
}
};
registerReceiver(usbReceiver, new IntentFilter(ACTION_USB_PERMISSION));
```
4. 访问USB设备:
```
UsbDeviceConnection connection = usbManager.openDevice(device);
UsbInterface usbInterface = device.getInterface(0);
UsbEndpoint endpoint = usbInterface.getEndpoint(0);
connection.claimInterface(usbInterface, true);
byte[] buffer = new byte[endpoint.getMaxPacketSize()];
int count = connection.bulkTransfer(endpoint, buffer, buffer.length, TIMEOUT);
```
请注意,这仅是一个简单的示例,并且需要根据您的具体需求进行修改和优化。