java.lang.SecurityException: No active admin owned by uid 10034 for policy #3
<p>I create a lock screen widget app recently. It always has the exception:</p>

<pre><code>（ java.lang.SecurityException: No active admin owned by uid 10034 for policy #3）
</code></pre>

<p>I try many methods and can not eliminate the exception. I open the activity to realize the purpose of the lock screen when the condition was founded.</p>

<pre><code>public class tempActivity extends Activity {
    private static final String TAG = "tempActivity"; 
    private DevicePolicyManager policyManager;
    private ComponentName componentName;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.temp);
        Log.e(TAG, "Activity created~");
        policyManager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
        componentName = new ComponentName(this, AdminReceiver.class);
        mylock();
    }

    private void mylock() {
        boolean active = policyManager.isAdminActive(componentName);
        if (!active) { // Without permission
            Log.e(TAG, "No authority~");
            activeManage(); // To get access
            policyManager.lockNow(); // And lock screen
        } else {
            Log.e(TAG, "Has authority");
            policyManager.lockNow(); // lock screen directly
        }
        this.finish();
    }

    private void activeManage() {
        Log.e(TAG, "activeManage");
        Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
        intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);
        intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, "developers：liushuaikobe");
        startActivityForResult(intent, 1);
    }
}
</code></pre>
