iOS 关于TouchID指纹解锁的实现

- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    //初始化上下文对象
    LAContext* context = [[LAContext alloc] init];
    //这个设置的使用密码的字体，当text=@""时，按钮将被隐藏

　　　　context.localizedFallbackTitle=@"输入密码解锁";

//这个设置的取消按钮的内容
    context.localizedCancelTitle=@"取消";
    //错误对象
    NSError* error = nil;
    NSString* result = @"需要验证您的touch ID";
    //首先使用canEvaluatePolicy 判断设备支持状态
    if ([context canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                             error:&error]) {
        NSLog(@"支持指纹识别");
        [context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
                localizedReason:result reply:^(BOOL success, NSError * _Nullable error) {
                    if (success) {
                        NSLog(@"验证成功 刷新主界面");
                    }else{
                        NSLog(@"%@",error.localizedDescription);
                        switch (error.code) {
                            case LAErrorSystemCancel:
                            {
                                NSLog(@"系统取消授权，如其他APP切入");
                                break;
                            }
                            case LAErrorUserCancel:
                            {
                                NSLog(@"用户取消验证Touch ID");
                                break;
                            }
                            case LAErrorAuthenticationFailed:
                            {
                                NSLog(@"授权失败");
                                break;
                            }
                            case LAErrorPasscodeNotSet:
                            {
                                NSLog(@"系统未设置密码");
                                break;
                            }
                            case LAErrorTouchIDNotAvailable:
                            {
                                NSLog(@"设备Touch ID不可用，例如未打开");
                                break;
                            }
                            case LAErrorTouchIDNotEnrolled:
                            {
                                NSLog(@"设备Touch ID不可用，用户未录入");
                                break;
                            }
                            case LAErrorUserFallback:
                            {
                                [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                                    NSLog(@"用户选择输入密码，切换主线程处理");
                                }];
                                break;
                            }
                            default:
                            {
                                [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                                    NSLog(@"其他情况，切换主线程处理");
                                }];
                                break;
                            }
                        }
                    }
                }];
    }else{
        NSLog(@"不支持指纹识别");
        switch (error.code) {
            case LAErrorTouchIDNotEnrolled:
            {
                NSLog(@"TouchID is not enrolled");
                break;
            }
            case LAErrorPasscodeNotSet:
            {
                NSLog(@"A passcode has not been set");
                break;
            }
            default:
            {
                NSLog(@"TouchID not available");
                break;
            }
        }
        
        NSLog(@"%@",error.localizedDescription);
    }
    
}