Menu

Set up Device Admin

Android's Device Administration API provides system-level device administration capabilities that enable the creation of security-aware apps. Android’s Device Administration provides an in-depth explanation of using the Device Administration API to create device admin apps.

Register the Device Admin Receiver

First, you must register the Device admin receiver in your app’s manifest. Your receiver must be a subclass of DeviceAdminReceiver that has both the BIND_DEVICE_ADMIN permission and the ability to respond to the ACTION_DEVICE_ADMIN_ENABLED intent.

In AndroidManifest.xml, insert the following xml anywhere inside the <application> tag.

<receiver
	android:name=".SampleAdminReceiver"
        android:description="@string/enterprise_device_admin_description"
        android:label="@string/enterprise_device_admin"
        android:permission="android.permission.BIND_DEVICE_ADMIN" >
            <meta-data
                android:name="android.app.device_admin"
                android:resource="@xml/device_admin_receiver" />
            <intent-filter>
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
            </intent-filter>
</receiver>	

The Android Device Manager also states that you must identify the security policies in use by the app in a <meta-data> entry. Since the app uses a Samsung Knox policy to disable the camera, you don't have to specify any native Android (DevicePolicyManager) policies. However, Android still requires you to create an empty device_admin_receiverfile.

In your project, navigate to app > src > res. Create a directory named xml. Inside this directory, create a XML resource file named device_admin_receiver.xml. and replace the auto-generated code with the following:

<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-policies>
    </uses-policies>
</device-admin>

Create the Device Admin Receiver class

Create a Device Admin Receiver java class named SampleAdminReceiver.java. The Device Admin Receiver should be located in: app > src > main >java> [your package name]

import android.app.admin.DeviceAdminReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class SampleAdminReceiver extends DeviceAdminReceiver {

    void showToast(Context context, CharSequence msg) {
        Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onEnabled(Context context, Intent intent) {
        showToast(context, "Device admin enabled");
    }

    @Override
    public void onDisabled(Context context, Intent intent) {
        showToast(context, "Device admin disabled");
    }
}

Create the Device Admin methods

Now, let's create the toggleAdmin() method. This method is invoked when the user taps ACTIVATE ADMIN. The DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN intent is started to add the app as a device administrator.

Paste the following methods into MainActivity():

    private void toggleAdmin() {
        boolean adminState = devicePolicyManager.isAdminActive(deviceAdmin);
        if (adminState) {
            utils.log(getString(R.string.deactivating_admin));
            // Deactivate application as device administrator
            devicePolicyManager.removeActiveAdmin(new ComponentName(this, SampleAdminReceiver.class));
            toggleAdminBtn.setText(getString(R.string.activate_admin));
        } else {
            try {
                utils.log(getString(R.string.activating_admin));
                // Ask the user to add a new device administrator to the system
                Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
                intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, deviceAdmin);
                // Start the add device administrator activity
                startActivityForResult(intent, DEVICE_ADMIN_ADD_RESULT_ENABLE);

            } catch (Exception e) {
                utils.processException(e, TAG);
            }
        }
    }

Tutorial Progress

You are 3/7 done! Go to the next step.