ios - Touch ID Crash issue -

ios - Touch ID Crash issue -

actually facing issue in touchid implementation. want implement passcode functionality apple. problem don't want show alert user apple.

nsstring *mylocalizedreasonstring = <#string explaining why app needs authentication#>; if ([mycontext canevaluatepolicy:lapolicydeviceownerauthenticationwithbiometrics error:&autherror]) { [mycontext evaluatepolicy:lapolicydeviceownerauthenticationwithbiometrics localizedreason:mylocalizedreasonstring reply:^(bool success, nserror *error) {

here if don't send mylocalizedreasonstring app crash.

you have show alert , provide reason string. part of apple's privacy , security requirements ios. need inform user why requesting touch id authentication

ios iphone ios8