TouchID的使用

第一步，先导入#import 头文件
第二步，设置TouchID对象

LAContext *touchID = [LAContext new];
NSError *error = nil;
NSString *touchIDSuccess = @"XXOO正在申请通过指纹验证！";

其中，[touchID canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics error:&error]用来验证TouchID是否可用，
[touchID evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:touchIDSuccess reply:^(BOOL success, NSError * _Nullable error){ }];用来进行指纹验证。
具体的代码如下：

- (IBAction)popTouchID:(id)sender
{
    dispatch_async(dispatch_get_main_queue(), ^{
        LAContext *touchID = [LAContext new];
        NSError *error = nil;
        NSString *touchIDSuccess = @"XXOO正在申请通过指纹验证！";
        if ([touchID canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                                 error:&error])
        {//支持touchID
            [touchID evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics localizedReason:touchIDSuccess reply:^(BOOL success, NSError * _Nullable error)
            {

                NSLog(@"ErrorCode:%ld",error.code);

                switch (error.code)
                {
                    case LAErrorAuthenticationFailed:
                    {
                        [self alertWithMessage:@"指纹验证失败"];
                    }
                        break;
                    case LAErrorUserCancel:
                    {
                        [self alertWithMessage:@"用户取消验证"];
                    }
                        break;
                    case LAErrorUserFallback:
                    {
                        [self alertWithMessage:@"用户进行了后退操作"];
                    }
                        break;
                    case LAErrorSystemCancel:
                    {
                        [self alertWithMessage:@"系统取消操作"];
                    }
                        break;
                    case LAErrorPasscodeNotSet:
                    {
                        [self alertWithMessage:@"用户尚未设置密码"];
                    }
                        break;
                    case LAErrorTouchIDNotEnrolled:
                    {
                        [self alertWithMessage:@"用户尚未设置 TouchID"];
                    }
                        break;
                    case LAErrorTouchIDLockout:
                    {
                        [self alertWithMessage:@"TouchID已停止运行"];
                    }
                        break;
                    case LAErrorAppCancel:
                    {
                        [self alertWithMessage:@"APP取消操作"];
                    }
                        break;
                    case LAErrorInvalidContext:
                    {
                        [self alertWithMessage:@"TouchID不可用"];
                    }
                        break;
                    case 0:
                    {
                        [self alertWithMessage:@"TouchID验证成功"];
                    }
                        break;
                    default:
                        break;
                }
            }];
        }
        else
        {//不支持touchID，或者错误次数太多，造成touchID不可用
            [self alertWithMessage:@"TouchID不可用"];
        }
    });
}

- (void)alertWithMessage:(NSString *)message
{
    dispatch_async(dispatch_get_main_queue(), ^{
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Tips"
                                                                                 message:message
                                                                          preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *action = [UIAlertAction actionWithTitle:@"Cancel"
                                                         style:UIAlertActionStyleCancel
                                                       handler:^(UIAlertAction * _Nonnull action) {

                                                       }];
        [alertController addAction:action];
        [self presentViewController:alertController animated:YES completion:nil];
    });
}

不足之处，还请多多指教。