问题
I was wondering how to show a UIActionSheet from the bottom of the screen. I have tried using the showInView: method with MainView as the view to show it in but I get the MainView Undeclared error.
回答1:
You need to reference the controllers view:
[actionSheet showInView:self.viewController.view]
回答2:
If you attempt to show the UIActionSheet on the window though you use TabBar or ToolBar UI, The bottom part of the ActionSheet doesn't respond to your touch. You'd be better to use as follows:
[[[UIApplication sharedApplication] delegate] window];
回答3:
or you can show it in the main window. it will be useful if you have a tabbar application.
[[[UIApplication sharedApplication] delegate] window];
来源：https://stackoverflow.com/questions/1702335/showing-a-uiactionsheet