Question

我创建了一个UIImageView然后我在ApplicationDidLaunch中为它提供了一个模糊的背景图像。此imageview与整个屏幕重叠，注定要覆盖底层视图控制器

UIImage *captureImage = [self captureView:tabBar.view];
backgroundImage.image = [captureImage applyExtraLightEffect];
backgroundImage.frame = [[UIScreen mainScreen] applicationFrame];

[tabBar.view addSubview:backgroundImage];

然后我要求提供很好的触摸ID。如果TouchID身份验证成功，我想删除带有漂亮的淡出动画的背景图像

[context evaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometrics
        localizedReason:@"Are you the device owner?"
                  reply:^(BOOL success, NSError *error) {
                      if (error) {
                          UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                                          message:@"There was a problem verifying your identity."
                                                                         delegate:nil
                                                                cancelButtonTitle:@"Ok"
                                                                otherButtonTitles:nil];
                          [alert show];
                          exit(0);
                          return;
                      }
                      if (success) {
                          NSLog(@"Passcode via TOUCH ID entered OK");

                          [UIView animateWithDuration:0.5
                                           animations:^{backgroundImage.alpha = 0;}
                                           completion:^(BOOL finished){[[tabBar.view viewWithTag:13] removeFromSuperview];; }];
                          // [UIView setAnimationDidStopSelector:@selector(startupAnimationDone:finished:context:)];
                          [UIView setAnimationDelegate:self];
                      }

现在我的问题是代码立即执行，但删除backgroundImage帧需要5-10秒才能执行。它发生在我的所有iDevices上。我不明白为什么在删除superview之前有一个延迟。有没有人有任何线索？

Answer 1

完成块可能没有在主线程上返回。如果是这种情况，那么如果您尝试更改视图，则视图将以意想不到的方式运行。尝试将所有视图操作代码放在dispatch_async(dispatch_get_main_queue())块中。

ApplicationDidLaunch中的RemoveFromSuperView UIImageView以延迟执行

1 个答案: