当应用程序已经打开并且连接了USBDevice时，应用程序有时可以与设备通信，有时它不会。我收到的错误每次都不同。常数是，它在三星Galaxy手机，Nexus 7，Nexus 10上按预期工作。如果应用程序从连接的设备启动，一切都按预期工作，大部分时间。
Manifest就像这样设置
<uses-feature android:name="android.hardware.usb.host" />
<uses-feature android:name="android.hardware.usb.UsbInterface" />
<activity android:label="@string/app_name"
android:screenOrientation="fullSensor" android:launchMode="singleTask"
android:configChanges="mcc|mnc|locale|touchscreen|keyboard|keyboardHidden|navigation|orientation|screenLayout|uiMode|screenSize|smallestScreenSize|fontScale"
android:name="com.realart.Beatmaker.UnityPlayerNativeActivity">
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter >
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>
<!-- USB Connect List -->
<meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
android:resource="@xml/device_filter" />
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
</intent-filter>
<meta-data android:name="unityplayer.UnityActivity" android:value="true" />
<meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="false" />
</activity>
在onCreate中，我通过以下方式检查应用程序是否是从意图启动的：
// Get the device that woke up the activity
UsbDevice connectedDevice = (UsbDevice)getIntent()
.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (connectedDevice != null) {
UsbManager manager = (UsbManager)getSystemService(Context.USB_SERVICE);
UsbDevice device = connectedDevice;
writeDeviceInfo(device);
initDataTransferThread(manager, device);
}
如果应用程序已经打开，并且因为launchMode是singleTask，我已经重写了onNewIntent方法
@Override
public void onNewIntent(Intent intent) {
final String DEVICE_CONNECTED = "android.hardware.usb.action.USB_DEVICE_ATTACHED";
String action = intent.getAction();
if (action.equals(DEVICE_CONNECTED)) {
Log.d(TAG, "Device connected");
final UsbManager manager = (UsbManager)getSystemService(Context.USB_SERVICE);
try {
final UsbDevice connectedDevice = (UsbDevice)intent
.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (connectedDevice != null) {
writeDeviceInfo(connectedDevice);
initDataTransferThread(manager, connectedDevice);
} else {
Log.d(TAG, "Device null");
}
} else {
Log.d(TAG, "Permission denied");
Log.d(TAG, "Asking for permission and trying again...");
manager.requestPermission(connectedDevice, permissionIntent);
}
} catch (Exception e) {
Log.d(TAG, "Exception throw: " + e.toString());
e.printStackTrace();
}
}
}
它几乎总是在该方法中击中允许拒绝其他块，所以它然后进入我设置的权限检查广播接收器：
// Attach Events
attachReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
Log.d(TAG, "Permissions receiver hit");
String action = intent.getAction();
Log.d(TAG, "Action requested: " + action);
UsbManager manager = (UsbManager)getSystemService(Context.USB_SERVICE);
if (intent.getAction().equals("com.realart.Beatmaker.USB_PERMISSION")) {
// Thread still running?
if (arduino != null) {
if (arduino.pipeline != null) {
Message msg = Message.obtain();
msg.what = Change.USB_DISCONNECTED;
arduino.pipeline.sendMessage(msg);
}
arduino = null;
}
synchronized (this) {
Log.d(TAG, "Checking permissions from user...");
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
boolean permissionGranted = intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false);
Log.d(TAG, "Permissions granted: " + permissionGranted);
if (permissionGranted) {
if (device != null) {
writeDeviceInfo(device);
initDataTransferThread(manager, device);
} else {
Log.d(TAG, "Device null");
}
} else {
Log.d(TAG, "Permission denied from user");
}
}
}
}
};
permissionIntent = PendingIntent.getBroadcast(this, 0, new Intent("com.realart.Beatmaker.USB_PERMISSION"), 0);
IntentFilter attachFilter = new IntentFilter("com.realart.Beatmaker.USB_PERMISSION");
registerReceiver(attachReceiver, attachFilter);
该过程似乎没有导致任何错误，并且每次都会写出设备信息。有时，它列出了两个接口，有时是0.这很奇怪，我不知道为什么会这样做。
这是我初始化设备的方式：
private boolean initSerialBus() {
try {
// Open device
connection = usbManager.openDevice(arduino);
if (connection == null) {
Log.d(TAG, "Opening device failed");
return false;
}
// Get serial interface
usbInterface = arduino.getInterface(1);
boolean interfaceClaimed = connection.claimInterface(usbInterface, FORCE_CLAIM);
Log.d(TAG, "USB Interface claimed: " + interfaceClaimed);
if (!interfaceClaimed) {
Log.d(TAG, "Trying again with kernel driver");
interfaceClaimed = connection.claimInterface(usbInterface, false);
if (!interfaceClaimed) {
Log.d(TAG, "Unable to claim interface.");
return false;
}
}
// Arduino USB serial converter setup
Log.d(TAG, "Data Transfter setup");
// Line state
int lineState = connection.controlTransfer(0x21, 0x22, 0, 0, null, 0, 0);
if (lineState < 0) {
Log.d(TAG, "Line state control transfer failed.");
Log.d(TAG, "Return value: " + lineState);
releaseUsbResources();
arduinoState.onArduinoError(new Exception("Control frame transfer error"));
return false;
}
Log.d(TAG, "Line state control frame: OK return: " + lineState);
// Line encoding (9600 Baud)
final byte[] lineEncoding = {
(byte) 0x80, 0x25, 0x00, 0x00, 0x00, 0x00, 0x08
};
int lineEncode = connection.controlTransfer(0x21, 0x20, 0, 0, lineEncoding, 7, 0);
if (lineEncode < 0) {
Log.d(TAG, "Line encoding control transfer failed.");
Log.d(TAG, "Return value: " + lineEncode);
releaseUsbResources();
arduinoState.onArduinoError(new Exception("Control frame transfer error"));
return false;
}
Log.d(TAG, "Line encoding control frame: OK return: " + lineEncode);
// I/O Endpoints
for (int i = 0; i < usbInterface.getEndpointCount(); i++) {
UsbEndpoint endpoint = usbInterface.getEndpoint(i);
if (endpoint.getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) {
if (endpoint.getDirection() == UsbConstants.USB_DIR_IN) {
arduinoIn = usbInterface.getEndpoint(i);
} else {
arduinoOut = usbInterface.getEndpoint(i);
}
}
}
// Ensure we found the endpoints
if (arduinoIn == null || arduinoOut == null) {
releaseUsbResources();
arduinoState.onArduinoError(new Exception("No usb endpoints found"));
return false;
}
Log.d(TAG, "I/O Enpoints found");
arduinoConnected = true;
} catch (Exception e) {
e.printStackTrace();
}
return arduinoConnected;
}
这是通常的logcat输出：
V/UsbHostManager( 2733): USB HOST UEVENT: {SUBSYSTEM=host_notify, STATE=ADD, DEVNAME=usb_otg, DEVPATH=/devices/virtual/host_notify/usb_otg, SEQNUM=18860, ACTION=change}
D/UsbHostManager( 2733): turnOnLcd ::
D/UsbHostNotification( 2733): setUsbObserverNotification : cancel id = 998563545, device = UsbDevices
D/UsbHostNotification( 2733): setUsbObserverNotification : notify id = 998563545, device = UsbDevices, title = USB connector connected.
D/UsbHostNotification( 2733): send the timeout : current 1413981920804, vailed = -2999, displayed = 1413981920803
D/UsbHostNotification( 2733): setUsbObserverNotification : cancel id = 998563545, device = UsbDevices
D/UsbHostManager( 2733): usbDeviceAdded : device :: /dev/bus/usb/002/077 [2341h:003dh] [02h,00h,00h] (CDC Control)
D/UsbHostManager( 2733): usbDeviceAdded : interface :: /dev/bus/usb/002/077 [2341h:003dh] [02h,02h,01h] (CDC Control)
D/UsbHostManager( 2733): usbDeviceAdded : interface :: /dev/bus/usb/002/077 [2341h:003dh] [0ah,00h,00h] (CDC Data)
D/UsbSettingsManager( 2733): deviceAttached: /dev/bus/usb/002/077 def package com.realart.Beatmaker
D/UsbSettingsManager( 2733): deviceAttached, send intent Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 (has extras) }
D/UsbSettingsManager( 2733): deviceAttached, call to resolveActivity started, Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 (has extras) }
D/UsbSettingsManager( 2733): resolveActivity : matches count = 1, defaultPackage = com.realart.Beatmaker
D/UsbSettingsManager( 2733): resolveActivity : defaultRI = ResolveInfo{425e9ad0 com.realart.Beatmaker/.UnityPlayerNativeActivity m=0x108000}
D/UsbSettingsManager( 2733): grantDevicePermission: UsbDevice[mName=/dev/bus/usb/002/077,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@42d33850] for 10212
D/UsbSettingsManager( 2733): grantDevicePermission: mDevicePermissionMap put UsbDevice[mName=/dev/bus/usb/002/077,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@42d33850] for {}
D/UsbSettingsManager( 2733): resolveActivity : permissionsGranted to ResolveInfo{425e9ad0 com.realart.Beatmaker/.UnityPlayerNativeActivity m=0x108000}
D/UsbSettingsManager( 2733): deviceAttached, call to resolveActivity ended, Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 cmp=com.realart.Beatmaker/.UnityPlayerNativeActivity (has extras) }
D/Unity (30871): Device connected
D/Unity (30871): Permission denied
D/Unity (30871): Asking for permission and trying again...
D/UsbSettingsManager( 2733): requestPermission:/dev/bus/usb/002/077 ,pi PendingIntent{42169a08: PendingIntentRecord{42c42748 com.realart.Beatmaker broadcastIntent}}
D/UsbSettingsManager( 2733): Request Permission for Device vendorId: 9025, productId: 61, package: com.realart.Beatmaker
D/UsbSettingsManager( 2733): hasPermission++
D/UsbSettingsManager( 2733): hasPermission: UsbDevice[mName=/dev/bus/usb/002/077,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.os.Parcelable;@4360cc38]for {10212=true}
D/UsbSettingsManager( 2733): requestPermission:/dev/bus/usb/002/077 has permissions
D/Unity (30871): Permissions receiver hit
D/Unity (30871): Action requested: com.realart.Beatmaker.USB_PERMISSION
D/Unity (30871): Checking permissions from user...
D/Unity (30871): Permissions granted: true
D/Unity (30871): Device name: /dev/bus/usb/002/077
D/Unity (30871): Vender id: 9025
D/Unity (30871): Product id: 61
D/Unity (30871): Class: class android.hardware.usb.UsbDevice
D/Unity (30871): Sub-class: 0
D/Unity (30871): Protocol: 0
D/Unity (30871): Num Interfaces: 2
D/Unity (30871): Device hash: 263427216
D/Arduino (30871): USB Interface claimed: false
D/Arduino (30871): Trying again with kernel driver
D/Arduino (30871): Unable to claim interface.
D/UsbSettingsManager( 2733): checkPermission: /dev/bus/usb/002/077
D/UsbSettingsManager( 2733): hasPermission++
D/UsbSettingsManager( 2733): hasPermission: UsbDevice[mName=/dev/bus/usb/002/077,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@42d33850]for {10212=true}
在logcat中打印以下行后似乎有明显的超时：
D/UsbHostNotification( 2733): send the timeout : current 1413981920804, vailed = -2999, displayed = 1413981920803
D/UsbHostNotification( 2733): setUsbObserverNotification : cancel id = 998563545, device = UsbDevices
如果应用程序的其余部分继续足够快，则问题不会发生，但如果它在该步骤上挂起几秒钟，则每次都会失败。但是，并不总是在同一个地方。有时在尝试声明接口时，有时在发送控制传输时，有时没有失败消息，但没有收到数据。
启动应用程序时，logcat输出如下所示：
--------- beginning of /dev/log/system
D/UsbHostNotification( 2733): setUsbObserverNotification : cancel id = 998563545, device = UsbDevices
--------- beginning of /dev/log/main
V/UsbHostManager( 2733): USB HOST UEVENT: {SUBSYSTEM=host_notify, STATE=ADD, DEVNAME=usb_otg, DEVPATH=/devices/virtual/host_notify/usb_otg, SEQNUM=19659, ACTION=change}
D/UsbHostManager( 2733): turnOnLcd ::
D/UsbHostNotification( 2733): setUsbObserverNotification : cancel id = 998563545, device = UsbDevices
D/UsbHostNotification( 2733): setUsbObserverNotification : notify id = 998563545, device = UsbDevices, title = USB connector connected.
D/UsbHostNotification( 2733): send the timeout : current 1413982261198, vailed = -2991, displayed = 1413982261189
D/UsbHostManager( 2733): usbDeviceAdded : device :: /dev/bus/usb/002/081 [2341h:003dh] [02h,00h,00h] (CDC Control)
D/UsbHostManager( 2733): usbDeviceAdded : interface :: /dev/bus/usb/002/081 [2341h:003dh] [02h,02h,01h] (CDC Control)
D/UsbHostManager( 2733): usbDeviceAdded : interface :: /dev/bus/usb/002/081 [2341h:003dh] [0ah,00h,00h] (CDC Data)
D/UsbSettingsManager( 2733): deviceAttached: /dev/bus/usb/002/081 def package com.realart.Beatmaker
D/UsbSettingsManager( 2733): deviceAttached, send intent Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 (has extras) }
D/UsbSettingsManager( 2733): deviceAttached, call to resolveActivity started, Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 (has extras) }
D/UsbSettingsManager( 2733): resolveActivity : matches count = 1, defaultPackage = com.realart.Beatmaker
D/UsbSettingsManager( 2733): resolveActivity : defaultRI = ResolveInfo{42458358 com.realart.Beatmaker/.UnityPlayerNativeActivity m=0x108000}
D/UsbSettingsManager( 2733): grantDevicePermission: UsbDevice[mName=/dev/bus/usb/002/081,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@4259eeb8] for 10212
D/UsbSettingsManager( 2733): grantDevicePermission: mDevicePermissionMap put UsbDevice[mName=/dev/bus/usb/002/081,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@4259eeb8] for {}
D/UsbSettingsManager( 2733): resolveActivity : permissionsGranted to ResolveInfo{42458358 com.realart.Beatmaker/.UnityPlayerNativeActivity m=0x108000}
D/UsbSettingsManager( 2733): deviceAttached, call to resolveActivity ended, Intent { act=android.hardware.usb.action.USB_DEVICE_ATTACHED flg=0x10000000 cmp=com.realart.Beatmaker/.UnityPlayerNativeActivity (has extras) }
D/UsbHostManager( 2733): onUEvent(device) :: action = add, devtype = usb_interface, device = null, product = 2341/3d/1, type = 2/0/0, interface = 2/2/1, devpath = /devices/platform/exynos-dwc3.0/exynos-xhci.0/usb2/2-1/2-1:1.0
D/UsbHostManager( 2733): onUEvent(device) :: action = add, devtype = usb_interface, device = null, product = 2341/3d/1, type = 2/0/0, interface = 10/0/0, devpath = /devices/platform/exynos-dwc3.0/exynos-xhci.0/usb2/2-1/2-1:1.1
D/Unity (31983): Device name: /dev/bus/usb/002/081
D/Unity (31983): Vender id: 9025
D/Unity (31983): Product id: 61
D/Unity (31983): Class: class android.hardware.usb.UsbDevice
D/Unity (31983): Sub-class: 0
D/Unity (31983): Protocol: 0
D/Unity (31983): Num Interfaces: 2
D/Unity (31983): Device hash: 263427241
D/Arduino (31983): USB Interface claimed: true
D/Arduino (31983): Data Transfter setup
D/Arduino (31983): Line state control frame: OK return: 0
D/Arduino (31983): Line encoding control frame: OK return: 7
D/Arduino (31983): I/O Enpoints found
D/Arduino (31983): Arduino bus initialized
D/UsbSettingsManager( 2733): checkPermission: /dev/bus/usb/002/081
D/UsbSettingsManager( 2733): hasPermission++
D/UsbSettingsManager( 2733): hasPermission: UsbDevice[mName=/dev/bus/usb/002/081,mVendorId=9025,mProductId=61,mClass=2,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@4259eeb8]for {10212=true}
D/Arduino (31983): Receiver thread started
D/Unity (31983): onArduinoReady
D/Arduino (31983): resetArduino
V/Unity (31983): sending message to unity = reset
V/Unity (31983): sending message to unity = onArduinoReady
当应用程序启动，设备已连接且onNewIntent方法被命中时，每次都会命中权限被拒绝的块，但是从未显示过要求权限的提示？
有没有人知道为什么这款平板电脑的行为如此奇怪？
型号：SM-T800
Android版：4.4.2
内核版本：3.4.39-2010469
内部版本号：KOT49H.T800XXU1ANFB
答案 0 :(得分：0)
如果有人遇到同样的问题，应用程序的主要部分是使用Unity创建的，它是在产生对意图作出反应的衍生线程与获取UsbInterface的Unity之间的竞争条件。在启动时，因为Unity尚未初始化，所以生成的线程能够在99％的时间内捕获接口，但是在Unity已经生成之后，Untiy通过JNI能够首先声明接口。我不完全确定为什么它会在平板电脑上声称它是传感器，而不是其他传感器，但可能与Exynos 5 Octa 5420芯片组有关，以及Unity如何决定某些传感器。