Android USBManager 調試故障通常涉及以下幾個步驟:
檢查USB權限:
<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />
連接USB設備:
獲取USB設備列表:
UsbManager
的getDeviceList()
方法獲取連接的USB設備列表:UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
HashMap<String, UsbDevice> deviceList = usbManager.getDeviceList();
Iterator<UsbDevice> deviceIterator = deviceList.values().iterator();
while (deviceIterator.hasNext()) {
UsbDevice device = deviceIterator.next();
// 處理設備
}
檢查設備連接狀態:
UsbDeviceConnection
的isConnected()
方法檢查設備是否已連接:UsbDeviceConnection connection = usbManager.openDevice(device);
boolean isConnected = connection != null && connection.isConnected();
if (!isConnected) {
// 處理設備未連接的情況
}
請求用戶授權:
UsbManager
的requestPermission()
方法:PendingIntent permissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
usbManager.requestPermission(device, permissionIntent);
處理USB權限廣播:
private final BroadcastReceiver usbPermissionReceiver = 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) {
// 設備已獲得權限,可以進行后續操作
}
} else {
Log.d(TAG, "permission denied for device " + device);
}
}
}
}
};
調試日志:
Log
類記錄調試信息,幫助你定位問題。例如:Log.d(TAG, "USB device connected: " + device.getDeviceName());
Log.d(TAG, "USB device vendor ID: " + device.getVendorId());
Log.d(TAG, "USB device product ID: " + device.getProductId());
檢查設備兼容性:
通過以上步驟,你可以有效地調試和解決Android USBManager相關的故障。如果問題仍然存在,請提供更多的錯誤信息和代碼片段,以便進一步分析。