When trying to use TouchID on my app, it hangs for a long time, and then will sometimes crash, and sometimes finally pass. I have never tried anything with Touch ID, so it's all very much new to me. My code is:
-(IBAction)touchID {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *student = [defaults objectForKey:@"firstName"];
NSString *usingTouch = [defaults objectForKey:@"useTouchID"];
if ([usingTouch isEqualToString:@"Yes"]) {
[passwordfield removeFromSuperview];
LAContext *context = [[LAContext alloc] init];
NSError *error = nil;
if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]) {
[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
localizedReason:@"Are you the device owner?"
reply:^(BOOL success, NSError *error) {
if (error) {
NSLog(@"%@", error);
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"There was a problem verifying your identity."
delegate:nil
cancelButtonTitle:@"Ok"
otherButtonTitles:nil];
[alert show];
return;
}
else if (success) {
NSString *nope = @"Yes";
[defaults setObject:nope forKey:@"firstName"];
[defaults synchronize];
[self updatetheview];
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"You are not the device owner."
delegate:nil
cancelButtonTitle:@"Ok"
otherButtonTitles:nil];
[alert show];
}
}];
} else {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
message:@"Your device cannot authenticate using TouchID."
delegate:nil
cancelButtonTitle:@"Ok"
otherButtonTitles:nil];
[alert show];
}
//Perform Touch ID Code
}
}
The Console shows this over and over again before finally acting as you would expect it to immediately:
Stack:(
0 CoreFoundation 0x000000018359cf60 + 148
1 libobjc.A.dylib 0x0000000198a47f80 objc_exception_throw + 56
2 CoreFoundation 0x000000018359ce90 + 0
3 Foundation 0x00000001845bb2d8 + 88
4 Foundation 0x0000000184441a1c + 56
5 Foundation 0x000000018443d5dc + 260
6 UIKit 0x0000000188c378c4 + 64
7 UIKit 0x0000000188b2aa78 + 240
8 UIKit 0x0000000188b2a32c + 116
9 UIKit 0x0000000188b2a1b8 + 504
10 UIKit 0x0000000188e3c834 + 228
11 UIKit 0x0000000188b28bf8 + 412
12 Fritch 0x0000000100186f40 -[DirectoryViewController updatetheview] + 180
13 Fritch 0x0000000100186cac __34-[DirectoryViewController touchID]_block_invoke + 316
14 LocalAuthentication 0x000000018599ee28 + 72
15 LocalAuthentication 0x000000018599e7e4 + 256
16 LocalAuthentication 0x000000018599b004 + 324
17 LocalAuthentication 0x000000018599b168 + 128
18 CoreFoundation 0x00000001835a2a70 + 144
19 CoreFoundation 0x00000001834a04d4 + 284
20 Foundation 0x00000001845c5b4c + 20
21 Foundation 0x00000001845c5940 + 796
22 Foundation 0x00000001845c79c8 + 292
23 libxpc.dylib 0x00000001994a0c80 + 28
24 libxpc.dylib 0x00000001994a0c24 + 40
25 libdispatch.dylib 0x000000010051dc68 _dispatch_client_callout + 16
26 libdispatch.dylib 0x000000010052a780 _dispatch_queue_drain + 1036
27 libdispatch.dylib 0x0000000100521958 _dispatch_queue_invoke + 464
28 libdispatch.dylib 0x000000010051dc68 _dispatch_client_callout + 16
29 libdispatch.dylib 0x000000010052cec8 _dispatch_root_queue_drain + 2344
30 libdispatch.dylib 0x000000010052c590 _dispatch_worker_thread3 + 132
31 libsystem_pthread.dylib 0x000000019946d470 _pthread_wqthread + 1092
32 libsystem_pthread.dylib 0x000000019946d020 start_wqthread + 4
)
The reply block of evaluatePolicy is not called on the main thread. You need to make sure all of your UI code in the reply block is done on the main thread.