Xamarin Android, detecting USB drive connection

Question

I'm using Visual Studio 2015 and Xamarin and I'm trying to detect when a user inserts an USB drive in an android app.

This is my BroadcastReceiver implementation.

 [BroadcastReceiver(Enabled =true)]
[IntentFilter(new[] { Intent.ActionMediaMounted })]
class DeviceMonitor : BroadcastReceiver, IDeviceMonitor
{
    public override void OnReceive(Context context, Intent intent)
    {
        if (DeviceAdded != null)
            DeviceAdded(this, new EventArgs());

        if (intent.Action.ToLower() == "android.intent.action.ums_connected")
        {
            Java.IO.File[] files = context.GetExternalMediaDirs();
        }
    }
}

The receiver is registered at the MainActivity in the OnCreate method

DeviceMonitor monitor = new Classes.DeviceMonitor();
        RegisterReceiver(monitor, new Android.Content.IntentFilter(Intent.ActionMediaMounted));

This is my AndroidManifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="auto" package="WebView.CrossPlatform.Server.Droid" android:versionCode="1">
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-feature android:name="android.hardware.usb.host" android:required="false" />
<application android:label="WebView.CrossPlatform.Server.Droid">
    <receiver android:name=".Classes.DeviceMonitor" android:enabled="true" android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MEDIA_MOUNTED" />
            <data android:scheme="file" />
        </intent-filter>
    </receiver>
</application>

But this does not seem to work. I've looked for solutions and tried about everything that I could find, but nothing is working.

Can anyone see what I'm doing wrong ?

Thanks,

score 0 · Answer 1 · answered Dec 05 '16 at 03:26

It seems that you only defined an action "android.intent.action.MEDIA_MOUNTED" in your manifest, but in your DeviceMonitor, you detect the "android.intent.action.ums_connected" action.

You can for example change your manifest like this:

<receiver android:name=".Classes.DeviceMonitor">
   <intent-filter>
        <action android:name="android.intent.action.UMS_CONNECTED" />
        <action android:name="android.intent.action.UMS_DISCONNECTED" />
   </intent-filter>
</receiver>

And in your DeviceMonitor:

public override void OnReceive(Context context, Intent intent)
{
    if (intent.Action == "android.intent.action.UMS_CONNECTED")
    {
        //TODO:
    }

    if (intent.Action == "android.intent.action.UMS_DISCONNECTED")
    {
        //TODO:
    }
}

The onreceive method is never called, so I doesn't matter what I put in there. The documentation also states that the "UMS_CONNECTED" action is deprecated. — Benjamien, Dec 05 '16 at 08:41
@Benjamien, Have you read this [answer](http://stackoverflow.com/questions/4600896/android-detecting-usb) which suggest to use `BatteryManager`? Anyway, we need to declare the action in manifest. — Grace Feng, Dec 05 '16 at 10:12

score 0 · Accepted Answer · answered Dec 07 '16 at 12:12

0

I found the problem. As it turns out I don't need to change the manifest by hand. By adding attributes to my classes the manifest is automatically generated. It works now by using the "android.intent.action.MEDIA_MOUNTED" action.

answered Dec 07 '16 at 12:12

Benjamien

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Xamarin Android, detecting USB drive connection

2 Answers2