uiactivityindicatorview

问题 I have added a refresh UIBarButtonItem to my navigation bar on my iPhone app. When the user taps the button I'd like the refresh button to change to the animated activity indicator and once the operation (in this case a download) is complete switch the activity indicator back to the refresh button. I have added the refresh button using IB. Then on the button tap I create a new activity indicator and keep an pointer to the original refresh button. Like so: refreshButtonItem = self

问题 This is a Q&A post. To inform the many other users I saw who struggled with this issue as I browsed through StackOverflow's database. None of these users ever got a solid answer (and most of them were posing the question years ago so I wasn't going to bump the post). The issue many struggled with is as follows: When you try to load a page in a UIWebView and the page then loads another page maybe via an iFrame or it loads an advertisement through javascript you end up getting the page loading

问题 I need to load some data in a table view and while this is going on in the background I want to add an activity indicator in order to show that there is a process going on and will hide once the process finishes. What would be the most efficient way to implement something like this? 回答1: Depends, whether you want to block your user or not and also how important is the activity indication. If you don't want to block user, use Application.networkActivityIndicatorVisible , if you want to have

问题 I'm trying to show a spinner during a possibly lengthy action invoked by a button press, but I can't get it to show up. Here's my code: class ViewController: UIViewController { var actInd : UIActivityIndicatorView! [...] override func viewDidLoad() { super.viewDidLoad() self.actInd = UIActivityIndicatorView(frame: CGRectMake(0,0, 50, 50)) as UIActivityIndicatorView self.actInd.center = view.center self.actInd.hidesWhenStopped = true self.actInd.activityIndicatorViewStyle =

问题 I have a method that does a time consuming operation, say something like ten consecutive calls to [[NSString alloc] initWithContentsOfURL:u]; I want a UIActivityIndicatorView that was in a hidden state before the method call to show and animate, so I write: activityIndicator.hidden = NO; [activityIndicator startAnimating]; at the beginning of the method but of course it won't work. The UIActivityIndicatorView will only animate once the method is over. This is not acceptable. I must show the

问题 On my main storyboard I created an Activity Indicator. I want to hide my activity indicator until the button has been pressed. Is there a way I can do that? When I press the button the activity indicator starts animating. self.indicator.hidden = NO; [self.indicator startAnimating]; [self performSelector:@selector(showData) withObject:nil afterDelay:2.0f]; Can I hide the activity indicator until the button has been pressed, and then show this activity indicator? 回答1: Select the Activity

问题 On my main storyboard I created an Activity Indicator. I want to hide my activity indicator until the button has been pressed. Is there a way I can do that? When I press the button the activity indicator starts animating. self.indicator.hidden = NO; [self.indicator startAnimating]; [self performSelector:@selector(showData) withObject:nil afterDelay:2.0f]; Can I hide the activity indicator until the button has been pressed, and then show this activity indicator? 回答1: Select the Activity

问题 I can successfully push only next view in my iPhone app. However, cause the next view retrieves data to populate the UITableViews , sometimes waiting time could be a few seconds or slightly longer depending on connection. During this time, the user may think the app has frozen etc. So, to counter this problem, I think implementing UIActivityIndicators would be a good way to let the user know that the app is working. Can someone tell me where I could implement this? Thanks. pushDetailView

问题 I can successfully push only next view in my iPhone app. However, cause the next view retrieves data to populate the UITableViews , sometimes waiting time could be a few seconds or slightly longer depending on connection. During this time, the user may think the app has frozen etc. So, to counter this problem, I think implementing UIActivityIndicators would be a good way to let the user know that the app is working. Can someone tell me where I could implement this? Thanks. pushDetailView

问题 When I call startAnimating on a UIActivityIndicatorView, it doesn't start. Why is this? [This is a blog-style self-answered question. The solution below works for me, but, maybe there are others that are better?] 回答1: If you write code like this: - (void) doStuff { [activityIndicator startAnimating]; ...lots of computation... [activityIndicator stopAnimating]; } You aren't giving the UI time to actually start and stop the activity indicator, because all of your computation is on the main