Android: Detect USB flash drive plugged in

问题

Is there a way to detect when a USB flash drive is plugged into an Android device? I'm able to detect an SD card using a broadcast receiver, but it doesn't work for USB. I'd like to avoid polling.

code to register receiver:

private void RegisterUpdateReceiver()
{
    IntentFilter intentFilter = new IntentFilter();
    intentFilter.addAction("android.intent.action.MEDIA_MOUNTED");
    intentFilter.addDataScheme("file");
    myReceiver = new MyReceiver();
    this.registerReceiver(myReceiver, intentFilter);
}

receiver code:

public class MyReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent)
    {
        String action = intent.getAction();
        if (action.equals("android.intent.action.MEDIA_MOUNTED")) 
        {
            // react to event
        }
}

回答1:

Android, at the SDK level, has no concept of USB drives. There are no rules for where they should be mounted, broadcasts for when they appear/disappear, etc. Perhaps some standardization in this area will come in future Android releases, but it is not there today.

回答2:

If detecting attaching and detaching the USB will work "android.hardware.usb.action.USB_DEVICE_ATTACHED" can be used. Make sure the definition of the receiver and the intent filter is added in the manifest as well.

回答3:

This is the xml version of the receiver in the AndroidManifest.xml:

        <receiver
            android:name="MyMountBroadcastReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MEDIA_MOUNTED"/>
                <action android:name="android.intent.action.MEDIA_UNMOUNTED"/>
                <data android:scheme="file" />
            </intent-filter>

        </receiver>

回答4:

This is how I made it work on Android 6.0. Basically, what we need to detect is when the drive is mounted which can be done by ACTION_MEDIA_MOUNTED that is "android.intent.action.MEDIA_MOUNTED".

Follow the steps below:

Register a broadcast receiver for "ACTION_USB_DEVICE_ATTACHED"
Register a broadcast receiver for "ACTION_MEDIA_MOUNTED"
Seek permission for using the device when "ACTION_USB_DEVICE_ATTACHED" action is received. Then you will receive broadcast for "ACTION_MEDIA_MOUNTED"

You can refer: https://developer.android.com/reference/android/content/Intent#ACTION_MEDIA_MOUNTED

Note: Registering broadcast receiver for ACTION_MEDIA_MOUNTED alone does not work. So used broadcast "ACTION_USB_DEVICE_ATTACHED" for permission purpose.

来源：https://stackoverflow.com/questions/8088338/android-detect-usb-flash-drive-plugged-in

标签

android

broadcastreceiver