当我将“已知”USB 设备连接到 Android 手机时出现的自动权限对话框中，用户按下“确定”或“取消”时，我试图处理该事件。
我正在使用 android.usb.host 库，可以在 Android 手机和设备之间发送和接收。此外，我使用 BroadcastReceiver 处理“USB_DEVICE_ATTACHED”和“USB_DEVICE_DETACHED”没有任何问题。
我想启用一种“自动连接”功能，因此我需要知道用户何时在自动显示的权限对话框中按下“确定”，但我根本无法在网上找到任何内容。我找到的只是“绕过对话框”，但这不是我想要或需要的。
当我将 USB 设备连接到 Android 手机时，会自动显示一个权限对话框，因为我使用了 Android 文档中的“device_filter.xml”解决方案，可以在此处查看Android USB 文档 https://developer.android.com/guide/topics/connectivity/usb/host#permission-d.
这是我处理 USB_DEVICE_ATTACHED 和 USB_DEVICE_DETACHED 事件的方式：
public NativeUsbService(ReactApplicationContext reactContext) {
...
// register device attached/detached event listeners
IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
reactContext.registerReceiver(usbReceiver, filter);
...
}
然后是广播接收器：
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
} else {
Log.d(TAG, "onReceive: DEVICE WAS ATTACHED AND WAS NULL :(");
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
Log.d(TAG, "onReceive: Device was detached!");
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
}
}
};
我尝试了多种不同的方法，但没有任何效果。
我尝试从意图中获取用户响应，例如使用手动权限请求，如下所示：
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
// THIS DOES NOT WORK ↓↓↓
if(intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
// The code never gets here...
}
} else {
Log.d(TAG, "onReceive: DEVICE WAS ATTACHED AND WAS NULL :(");
sendEvent("onDeviceAttached", false);
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
}
}
};
我还尝试通过首先将操作名称添加到我的类变量中来向广播接收器添加 USB 权限侦听器：
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
然后将操作添加到我的意图过滤器中，如下所示：
public NativeUsbService(ReactApplicationContext reactContext) {
// register device attached/detached event listeners
IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
filter.addAction(ACTION_USB_PERMISSION); // added action to my intent filter
reactContext.registerReceiver(usbReceiver, filter);
}
最后对这个动作做出这样的反应：
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
Log.d(TAG, "onReceive: Device was detached!");
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
sendEvent("onDeviceDetached", true);
}
else if (action.equals(ACTION_USB_PERMISSION)) {
Log.d(TAG, "onReceive: ACTION_USB_PERMISSION");
if(intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
Log.d(TAG, "onReceive: EXTRA_PERMISSION_GRANTED = true");
} else Log.d(TAG, "onReceive: EXTRA_PERMISSION_GRANTED = false");
}
}
};
请让我知道任何缺失的信息。
任何帮助是极大的赞赏。
