Touch ID Swift

biometrics.swift

let myContext = LAContext()
var authError: NSError?

// Set the reason string that will appear on the authentication alert.
var myReasonString = "String explaining why app needs authentication"

if myContext.canEvaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, error: &authError) {
    [myContext.evaluatePolicy(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, localizedReason: myReasonString, reply: { (success: Bool, evalPolicyError: NSError?) -> Void in

        if success {
            // User authenticated successfully
        } else {
            // Authenticate failed
        }
    })]
} else{
    // Could not evaluate policy; check authError
}