在UINavigationBar中添加左箭头返回按钮

在iPhone里面最讨厌的控件之一就是UINavigationBar了。这个控件样式修改不方便，连添加按钮也特别麻烦。下面的例子是如何手动添加带箭头的按钮：

UINavigationItem *item = [navBar.items objectAtIndex:0];
UINavigationItem *back = [[UINavigationItem alloc] initWithTitle:@"Back"];
NSArray *items = [[NSArray alloc] initWithObjects:back,item,nil];
[navBar setItems:items];

- (BOOL)navigationBar:(UINavigationBar *)navigationBar
        shouldPopItem:(UINavigationItem *)item{
    //在此处添加点击back按钮之后的操作代码  
    return FALSE;

}

Yes! There is a way of using the backBarButton with a custom action. No, it’s not by overriding the backBarButton property of navigationItem. This is not an ugly solution with images that simulate the “Back”-button (arrow-shaped.) It’s possible to use the backBarButton for popping the current viewController as normal, but than with other animations such as UIViewAnimationTransitionCurlDown.

Enough said, the solution is simple. You have to subclass your navigationController’s  popViewControllerAnimated:(BOOL)animated. So create a custom navigationController:

customNavigationController.h

#import
@interface customNavigationController : UINavigationController {}
@end

And a custom “popViewControllerAnimated:(BOOL)animated”, this popViewControllerAnimated-function uses the “UIViewAnimationTransitionCurlDown” when popping from a SettingsTableView.

customNavigationController.m

#import "customNavigationController.h"
#import "SettingsTableController.h"
 
@implementation customNavigationController
 
- (UIViewController *)popViewControllerAnimated:(BOOL)animated
{
 if([[self.viewControllers lastObject] class] == [SettingsTableController class]){
 
  [UIView beginAnimations:nil context:NULL];
  [UIView setAnimationDuration: 1.00];
  [UIView setAnimationTransition:UIViewAnimationTransitionCurlDown
     forView:self.view cache:NO];
 
  UIViewController *viewController = [super popViewControllerAnimated:NO];
 
  [UIView commitAnimations];
 
  return viewController;
 } else {
  return [super popViewControllerAnimated:animated];
 }
}
@end

Use your custom navigationController in your appDelegate:

customNavigationController *navigationController =
 [[customNavigationController alloc] 
  initWithRootViewController:rootView];

14 Responses to “Custom action on Back Button UINavigationController”

1. Rob on December 16th, 2009 at 03:06