Android: BroadcastReceiver when insert/remove the

问题:

My application don't catch "ACTION_USB_DEVICE_ATTACHED" but "ACTION_USB_DEVICE_DETACHED" work fine. Application start correctly if I connect usb device but I disconnect during execution BroadcastReceiver right catch "ACTION_USB_DEVICE_DETACHED". If I attach again BroadcastReceiver don't catch anything.

    IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
rocrailService.registerReceiver(mUsbReceiver, filter);


  // BroadcastReceiver when insert/remove the device USB plug into/from a USB port  
  BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
  public void onReceive(Context context, Intent intent) {
    String action = intent.getAction();
    System.out.println("BroadcastReceiver Event");
    if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
        mSerial.usbAttached(intent);
        mSerial.begin(mBaudrate);
        loadDefaultSettingValues();
        Run=true;
        start();
        System.out.println("BroadcastReceiver USB Connected");

    } else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
        mSerial.usbDetached(intent);
        mSerial.end();
        Run=false;
        System.out.println("BroadcastReceiver USB Disconnected");
    }
  }

And manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.DCCWLocoDisplay"
android:versionCode="0"
android:versionName="0" >

<uses-sdk android:targetSdkVersion="12"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/>
<uses-permission android:name="android.permission.WRITE_SETTINGS"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>   
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

<application
    android:icon="@drawable/dccw"
    android:label="@string/app_name" >
    <activity android:icon="@drawable/cab_64" android:name="net.DCCWLocoDisplay.activities.ActRCCab" android:theme="@style/FullHeightMainDialog" android:label="@string/app_name" >
        <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>
            <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" 
               android:resource="@xml/device_filter" />      
    </activity>
    <activity android:name="net.DCCWLocoDisplay.activities.ActPreferences" android:theme="@style/FullHeightDialog" />
    <activity android:name="net.DCCWLocoDisplay.activities.ActAccessory" android:theme="@style/FullHeightDialog" />
    <activity android:name="net.DCCWLocoDisplay.activities.ActAbout" android:theme="@style/FullHeightDialog" />
    <activity android:name="net.DCCWLocoDisplay.activities.ActProgramming" android:theme="@style/FullHeightDialog" />
    <activity android:name="net.DCCWLocoDisplay.activities.ActSteps" android:theme="@style/FullHeightDialog" />
    <service android:name="net.DCCWLocoDisplay.DCCWLocoDisplay"/>
    </application>

 </manifest>

Device filter (I check vendor and product id):

<resources>
<!-- 0x0403 / 0x6001: FTDI FT232R UART -->
<usb-device vendor-id="1027" product-id="24577" /> <!-- FT232RL -->
</resources>

回答1:

Everything works as was described above, except little changes! On my research singleTask in application tag didn't help, but helped when I put it in activity tag

<activity
...
android:launchMode="singleTask">

It provided me with ANDROID started to send onNewIntent to activity. And on onNewIntent I just had to get device from intent, with out any requests for permissions:

@Override
protected void onNewIntent(Intent intent)
{
    super.onNewIntent(intent);
    if(intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED))
    {
        UsbDevice device  = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

回答2:

add this permission also :)

<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />

回答3:

Also try adding in <application android:launchMode="singleTask">. This works for me with USB_ACCESSORY_ATTACHED, may work for you as well.

回答4:

I was able to resolve this issue by:

1. Add android:launchMode="singleTask" attribute in Launcher Activity

2. Add this Intent Filter in your Launcher Activity

   <intent-filter>
       <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
   </intent-filter>
   

3. Add metadata to your Launcher Activity

   <meta-data
       android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
       android:resource="@xml/device_filter" 
   />
   

4. Override the OnNewIntent Method in your Launcher Activity

   protected void onNewIntent(Intent intent) {
       if(intent.getAction().equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)){
           getPermission();
       }
   };
   

   5. Now if you will detach -> attach again a USB Device, onNewIntent() Method will be called..

回答5:

Android Reference for Activity says for using onNewIntent():

"This is called for activities that set launchMode to "singleTop" in their package, or if a client used the FLAG_ACTIVITY_SINGLE_TOP flag when calling startActivity(intent)"

So launchMode singleTop == singleTask?