objective-c - 用 UIActivityIndi​​catorView 替换 UIBarButtonItem

Question

我想用 UIActivityIndi​​catorView 替换我的 UIBarButtonItem(用于刷新)，刷新完成后，我想返回刷新按钮并删除UIActivityIndi​​catorView.

Answer 1

只需创建两个不同的UIBarButtonItems

一个用于事件指示器，另一个用于普通 UIBarButtonItem。

UIActivityIndicatorView * activityView = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 25, 25)];
[activityView sizeToFit];
[activityView setAutoresizingMask:(UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin)];
UIBarButtonItem *loadingView = [[UIBarButtonItem alloc] initWithCustomView:activityView];
[self.navigationItem setRightBarButtonItem:loadingView];
[loadingView release];
[activityView release];

UIBarButtonItem * normalButton = [[UIBarButtonItem alloc] initWithTitle...];
[self.navigationItem setRightBarButtonItem:normalButton];
[normalButton release];

当你想切换它们时，只需将 rightBarButtonItem 重新分配给任何一个即可。