UISearchBar取消按钮

Question

在iOS 5上使用带有showCancelButton = YES的UISearchBar。希望在键盘跌落时取消按钮保持启用状态。使用以下代码似乎不起作用：

    for (id subView in self.searchControl.subviews)
    {
        if ([subView isKindOfClass:[UIButton class]])
        {
            UIButton *cancelButton = (UIButton *)subView;
            [cancelButton setEnabled:YES];
            break;
        }         
    }

subView实际上是一个UINavigationButton，看起来不是UIButton的子类。我在这里失踪了什么???????也无法在Apple文档中找到有关UINavigationButton类的任何信息。

Answer 1

设置您的搜索栏委托，然后放置此代码。

- (void) searchBarSearchButtonClicked:(UISearchBar*) theSearchBar
  {
     [theSearchBar resignFirstResponder];
     [theSearchBar setShowsCancelButton:NO animated:YES];
  }
 - (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar
  {
     [searchBar setShowsCancelButton:YES animated:YES];
  }
  - (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar
  {
     [searchBar resignFirstResponder];
     [searchBar setShowsCancelButton:NO animated:YES];
  }

Swift 3.0

func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
     searchBar.resignFirstResponder()
     searchBar.setShowsCancelButton(false, animated: true)
}
func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
     searchBar.setShowsCancelButton(true, animated: true)
}
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
     searchBar.resignFirstResponder()
     searchBar.setShowsCancelButton(false, animated: true)
}

Answer 2

只是为了改善Kurt Spindler在他的帖子上所说的话。虽然这可能并不优越，但它更受欢迎。我用dispatch来做同样的事情。

-(void)searchBarTextDidEndEditing:(UISearchBar *)searchBar{
    for (UIView *subview in searchBar.subviews)
    {
        if ([subview isKindOfClass:[UIButton class]])
        {
            int64_t delayInSeconds = .001;
            dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
            dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
                UIButton * cancelButton = (UIButton *)subview;
                [cancelButton setEnabled:YES];
            });
            break;
        }
    }
}

这应该适用于需要帮助的所有人保持取消。确保稍后在单击取消或搜索时隐藏它。

- (void)searchBarCancelButtonClicked:(UISearchBar *)searchBar{
    [searchBar resignFirstResponder];
    [searchBar setShowsCancelButton:NO animated:YES];
}

Answer 3

我不得不在我的应用程序中解决同样的问题。在分数延迟后尝试执行上述代码，例如

[self performSelector:@selector(delayedEnable:) withObject:cancelButton afterDelay:0.001];

- (void)delayedEnable:(UIButton*)button {
    button.enabled = YES;
}

这很难看，但这就是为我工作所需要的。或者，如果您实际使用UISearchDisplayController来显示结果，它还应该为您修复取消按钮行为（我认为 - 我已经深入研究了这个问题）。

Answer 4

我在搜索栏取消按钮上放置了一个自定义取消按钮。

Answer 5

我知道这个已经老了，但是我能够解决它而且我找不到任何其他解决它的东西，所以这就是有效的（在Swift 3中）：

键盘隐藏时启用取消按钮。将其添加到viewDidLoad（）：

NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardNotification(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)

在keyboardNotification（notification :)方法中，对keyboardDidHide通知作出反应：

func keyboardNotification(notification: NSNotification) {
    if notification.name == Notification.Name.UIKeyboardDidHide {
        self.enableSearchCancelButton()
    }
}

enableSearchCancelButton取自其他人回答here的内容。

func enableSearchCancelButton() {
    //enable the cancel button
    for view1 in searchBar.subviews {
        for view2 in view1.subviews {
            if let button = view2 as? UIButton {
                button.isEnabled = true
                button.isUserInteractionEnabled = true
            }
        }
    }
}

最后，不要忘记以观察者的身份删除视图控制器：

deinit {
    NotificationCenter.default.removeObserver(self)
}

Answer 6

斯威夫特5：，斯威夫特4：

if let btnCancel = searchBar.value(forKey: "cancelButton") as? UIButton {
    btnCancel.isEnabled = true
}