What I do:
I am using the following tutorial to grasp the basic understanding on how to use fingerprint authentication in Android: http://joerichard.net/android/android-fingerprint-example/
I basically follow it except that I added a button and I want to authenticate a user when the button is clicked.
So I have the following changes
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn = (Button) findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
authentication();
}
});
...
protected void authentication(/* Bundle savedInstanceState */) {
//super.onCreate(savedInstanceState);
//setContentView(R.layout.activity_main);
...
My problem:
When I click the button the following notification is called (in "FingerprintHandler.java"):
Toast.makeText(appContext,
"Authentication error\n" + errString ,
Toast.LENGTH_LONG).show();
The errString is Fingerprint operation canceled.
and the Error message ID is 5.
By searching I found here that it correspond to FINGERPRINT_ACQUIRED_TOO_FAST, however I don't understand why this happen.
What I tried:
I tried to click the button while having my finger on the scanner but the notification is immediate which make me believe that it does not even listen/scan for a fingerprint.
I have also tried to make it work without the button but in that case nothing happens.
If you see what could go wrong or have directions in which I could investigate let me know.
Thank you.
My sensor was not working very well. It takes many tries to have a reading (and some time it does not work at all). Thus I would re-try by clicking on the button causing the error.
The function would not have any reading from the scanner when clicked again the button and give the error FINGERPRINT_ACQUIRED_TOO_FAST.
The fact that this specific error (TOO_FAST) is trigger didn't help me in my situation because as I explained this error message is trigger when clicking the button.
If anyone encounter the same problem give more time/chances to your sensor to recognize that a finger is being read.