abpeoplePickerNavigationController-删除“取消”按钮而不使用私有方法/属性?

这一个

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
  UIView *custom = [[UIView alloc] initWithFrame:CGRectMake(0.0f,0.0f,0.0f,0.0f)]; 
  UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithCustomView:custom]; 
  //UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addAction)]; 
  [viewController.navigationItem setRightBarButtonItem:btn animated:NO]; 
  [btn release]; 
  [custom release]; 
}

工作完美!

本文中使用委托方法navigationcontroller:willshowviewcontroller:animated:do work的示例,但您可能希望在自己的控制器中添加自己的导航项,并且给定的选项将删除您在自己的控制器中设置的任何内容。以下是我成功使用的代码,用于使此选项正常工作:

- (void)navigationController:(UINavigationController *)navigationController
      willShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animated {

    // Here we want to remove the 'Cancel' button, but only if we're showing
    // either of the ABPeoplePickerNavigationController's top two controllers
    if ([navigationController.viewControllers indexOfObject:viewController] <= 1) {

        viewController.navigationItem.rightBarButtonItem = nil;
    }
}

请注意,导航控制器堆栈中有两个视图控制器,一个用于联系人组,另一个用于联系人列表。这就是为什么我们不能只检查FI视图控制器是导航控制器的顶视图控制器。

对此没有答案-如果您不能接受取消操作,请编写一个新的人员选取器。

您可以通过选取器子视图来实现这个结果。只是有点无聊…

我还没有尝试过,但我认为uby是在说要遍历选择器的子视图,直到找到iskindofclass:[uibarbuttonitem class]的子视图,然后您可以更改它的title属性。它也可能在导航栏的“item”数组中。

将委托设置为PeoplePickerController控制器。 在委托类中,使用此委托方法。

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
 UIView *pCustomView = [[UIView alloc] initWithFrame:CGRectMake(0,0,0,0)];
 UIBarButtonItem *pBtn = [[UIBarButtonItem alloc] initWithCustomView:pCustomView];
 [viewController.navigationItem setRightBarButtonItem:pBtn animated:NO];
 [pBtn release];
 [pCustomView release];
}

确保将选择器对象的委托(不是PeoplePickerDelegate,只是委托)设置为实现以下方法的类:

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
UIView *custom = [[UIView alloc] initWithFrame:CGRectMake(0,0,0,0)];
UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithCustomView:custom];
[viewController.navigationItem setRightBarButtonItem:btn animated:NO];
[btn release];
[custom release];
} 

它工作得很好,但在iOS 4中还有一件事。当我使用快速应用程序切换功能切换回我的应用程序时,取消按钮再次出现。

方法

- (void)navigationController:(UINavigationController *)navigationController  
      willShowViewController:(UIViewController *)viewController
                    animated:(BOOL)animated

不会接到电话。所以我这样做:

- (void)applicationDidEnterBackground:(UIApplication *)application {
    id topView = pickerControllerDelegate.peoplePicker.topViewController;
    topView.navigationItem.rightBarButtonItem = nil;
}

它工作得很好。

根据Russel B,你可以改写你的 可视检测器

这对我很有用:

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    UINavigationItem *item = (UINavigationItem *)[self.navigationBar.items lastObject];
    item.rightBarButtonItems = [[NSArray alloc] init];

    item.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(addPerson)];
}

编辑:参见下面的注释。这是一个不该做什么的例子。

我试图通过对abpeoplePickernavigationController的子类化并截获所有更改当前导航视图控制器视图的事件,从而获得公共API所需的行为。然后就可以导航视图层次结构并清除所有不需要的按钮。

您可以从委托导航视图层次结构,但不知道更改视图状态的事件…这使得取消按钮很难被取消并使其保持不变。

本代码 有点 为我工作(注:暴力可以杀死所有的右手按钮):

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self killCancelButton];
}

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
    [super pushViewController:viewController animated:animated];
    [self killCancelButton];
}

- (UIViewController*)popViewControllerAnimated:(BOOL)animated {
    UIViewController *result = [super popViewControllerAnimated:animated];
    [self killCancelButton];
    return result;
}

- (void)killCancelButton {
    for (NSUInteger itemIdx = 0; itemIdx < self.navigationBar.items.count; itemIdx++) {
        UINavigationItem *item = [self.navigationBar.items objectAtIndex:itemIdx];
        item.rightBarButtonItems = [[NSArray alloc] init];
    }
}