Fingerprint: too many attempts issue

Question

I am trying to implement fingerprint introduced in Android-6.0-marshmallow, but face an issue.
The issue being that when I am try to run the sample code provided here

android-FingerprintDialog

it shows a "Too many attempts" error more than once.
To reproduce the issue, the steps are

1 - Click on purchase button
2 - Provide wrong touch id until the "too many attempts" error occur
3 - Provide password
4 - Again click on purchase button.

Now it again shows the "Too many attempts" error and asks for a password (which is not the supposed behaviour)

Please tell me how to fix this issue.

Answer 1

The specific implementation of the fingerprint API may vary among the different device manufacturers. The fingerprint API provides a "standard," but the open source nature of the Android OS means that customization may also occur. I have done testing with Huawei P6, LG 5X, and the Samsung S5, S6, and S7. (The Samsung devices use the proprietary Pass API, but demonstrate similar behaviors to the Android fingerprint API.) The scenarios I have seen in my experience in working with the Android 6.0 fingerprint API after the max failed authentication attempts has been reached:

• Locking the fingerprint scanner for 30 seconds.
• Locking the fingerprint scanner and requiring the backup password.
• Locking the fingerprint scanner for 30 seconds and requiring the backup password.

Does the fingerprint scanner become available again after you enter the backup password and wait 30 seconds? It would also be helpful to know which devices (manufacturers and models) you have tested against.