Android的USB Host API简单使用代码示例
时间: 2023-04-07 11:05:41 浏览: 133
以下是一个简单的Android USB Host API使用示例代码:
```
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
private UsbManager usbManager;
private PendingIntent permissionIntent;
private UsbDevice device;
private UsbDeviceConnection connection;
private UsbInterface usbInterface;
private UsbEndpoint endpointIn;
private UsbEndpoint endpointOut;
// 初始化USB Manager和Permission Intent
usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
permissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
// 获取USB设备列表
HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
// 遍历设备列表,找到需要连接的设备
for (UsbDevice usbDevice : deviceList.values()) {
if (usbDevice.getVendorId() == VENDOR_ID && usbDevice.getProductId() == PRODUCT_ID) {
device = usbDevice;
break;
}
}
// 如果找到了设备,请求USB权限
if (device != null) {
usbManager.requestPermission(device, permissionIntent);
}
// 在BroadcastReceiver中处理USB权限请求结果
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 usbDevice = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (usbDevice != null) {
// 获取USB设备连接
connection = usbManager.openDevice(usbDevice);
if (connection != null) {
// 获取USB接口和端点
usbInterface = usbDevice.getInterface(0);
endpointIn = usbInterface.getEndpoint(0);
endpointOut = usbInterface.getEndpoint(1);
// 打开USB接口
connection.claimInterface(usbInterface, true);
}
}
} else {
Log.d(TAG, "USB permission denied");
}
}
}
}
};
// 发送数据到USB设备
private void sendToUsbDevice(byte[] data) {
if (connection != null && endpointOut != null) {
int result = connection.bulkTransfer(endpointOut, data, data.length, TIMEOUT);
if (result < 0) {
Log.e(TAG, "Failed to send data to USB device");
}
}
}
// 从USB设备接收数据
private byte[] receiveFromUsbDevice() {
if (connection != null && endpointIn != null) {
byte[] buffer = new byte[endpointIn.getMaxPacketSize()];
int result = connection.bulkTransfer(endpointIn, buffer, buffer.length, TIMEOUT);
if (result >= 0) {
return buffer;
} else {
Log.e(TAG, "Failed to receive data from USB device");
}
}
return null;
}
```
希望这个示例代码能够帮助你使用Android USB Host API。