The problem:
There was an image here, but the link went dead. It shows a UIImagePickerController shown inside a popover, as a view inside of another controller (that is, it's not the root VC of the popover). It sports a Cancel button.
Can this button be killed in a popover? I can remove the button in the ABPeoplePicker*Controller that appears when picking Contacts by editing the private VC's navigation item on the fly, but this one eludes me (no UINavigationControllerDelegate methods are called by the UIIPC).
I think you can change it to something else (not sure about removing) because UIImagePickerController inherits UINavigationController. Then you can get
UINavigationBar *bar = picker.navigationBar;
[bar setHidden:NO];
bar.navigationItem.rightBarButtonItem = doneButton;
来源:https://stackoverflow.com/questions/2980156/can-the-cancel-button-be-removed-from-a-uiimagepickercontroller-in-os-3-2