How To Display Toast On Lock Screen After Failed Password Attempt

I am trying to show a Toast on the lock screen after a user enters the wrong password 3 times. I am able to verify that the user has failed 3 times through the log console, but wou

Solution 1:

import android.app.admin.DeviceAdminReceiver;
    import android.app.admin.DevicePolicyManager;
    import android.content.ComponentName;
    import android.content.Context;
    import android.content.Intent;
    import android.util.Log;
    import android.widget.Toast;

    publicclassAdminReceiverextendsDeviceAdminReceiver {

        @OverridepublicvoidonPasswordFailed(Context ctxt, Intent intent) {
            Log.d("LockScreen", "onPasswordFailed");
            DevicePolicyManagermgr= (DevicePolicyManager) ctxt.getSystemService(Context.DEVICE_POLICY_SERVICE);
            intno= mgr.getCurrentFailedPasswordAttempts();
            if (no >= 3) {
                Log.d("LockScreen", "Failed 3 times");
                //Toast does not show//ctxt is??                //Toast.makeText(ctxt, R.string.password_failed, Toast.LENGTH_LONG)//                        .show();//try this
Toast.makeText(getActivity(), "This is my Toast message!",
   Toast.LENGTH_LONG).show();    
        }
        }

        @OverridepublicvoidonPasswordSucceeded(Context ctxt, Intent intent) {
            Toast.makeText(ctxt, R.string.password_success, Toast.LENGTH_LONG)
                    .show();
        }
    }

This method allow you to customize your toast : Customizing your toast

LayoutInflatermyInflater= LayoutInflater.from(this);
Viewview= myInflater.inflate(R.layout.your_custom_layout, null);
Toastmytoast=newToast(this);
mytoast.setView(view);
mytoast.setDuration(Toast.LENGTH_LONG);
mytoast.show();

Solution 2:

The problem is when you show the toast.the lock screen will cover the Toast. because It is not unlocked yet It can be solved by

1. Send a Notification with a message.

2. Create a Transparent Activity. with some custom view to display message. and add below flags to your activity. and just start it and set timer to kill itself in 3 second.

   getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON|
       WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD|
       WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED|
       WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);