objective-c - 如何将事件指示器添加到导航栏？

Question

嘿，当我的用户在选择器轮中更改选择时，我想在导航栏的右上角显示一个事件指示器。我不知道如何在那里添加事件指示器，我只能在那里添加普通的导航栏按钮。有什么帮助吗？提前致谢!

Answer 1

UIActivityIndicatorView *activityIndicator =  
[[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];  
UIBarButtonItem *barButton = [[UIBarButtonItem alloc] 
                                         initWithCustomView:activityIndicator];  
[[self navigationItem] setRightBarButtonItem:barButton];  

[barButton release];  
[activityIndicator startAnimating];  

这应该有效。 来自:http://iosdevelopertips.com/user-interface/adding-an-activity-indicator-spinner-to-navigation-bar.html