LocalAuthentication Namespace

Supports authentication from users for specific policies.


The LocalAuthentication namespace, introduced in iOS 8, allows the app to require the user to authenticate with TouchID, as shown in the following example:

C# Example

btn.TouchUpInside += async(s,e) => {
    var ctxt = new LAContext();
    var error = new NSError();
    if(ctxt.CanEvaluatePolicy (LAPolicy.DeviceOwnerAuthenticationWithBiometrics, out error))
        var authenticated = await ctxt.EvaluatePolicyAsync(LAPolicy.DeviceOwnerAuthenticationWithBiometrics, "Authenticate to confirm message");
        if (authenticated)


LAContextThe context in which authentication policies are evaluated.
LAContextReplyHandlerSignature for a function to be invoked in response to a LocalAuthentication.LAContext.EvaluatePolicy invocation.
LAPolicyAuthentication policies.
LAStatusStatus and error codes returned by methods in LocalAuthentication.