更改选定的 TabBarItem 字体 iOS

Question

我有一个 TabBar。我正在尝试对其进行样式设置，以便 TabBarItems 上的标题对于正常状态和选定状态具有不同的字体。对于正常状态，我想要 Helvetica Neue Light，对于选定状态，我想要 Helvetica Neue Medium。无论我做什么，我似乎都无法让这两个州的字体不同。变色效果很好。这是我目前拥有的：

  // Set the tab bar title appearance for normal state.
  [[UITabBarItem appearance] setTitleTextAttributes:@{
     NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue-Light"
                                          size:16],
     NSForegroundColorAttributeName: [CMK8Colors grayColor]
   }
                                           forState:UIControlStateNormal];

  // Set the tab bar title appearance for selected state.
  [[UITabBarItem appearance] setTitleTextAttributes:@{
     NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue-Medium"
                                          size:16],
     NSForegroundColorAttributeName: [CMK8Colors blueColor]
   }
                                           forState:UIControlStateSelected];

请帮忙。

Answer 1

好消息和坏消息。

坏消息，这比只使用外观代理要难一点。

好消息没那么难！

标题

#import <UIKit/UIKit.h>

@interface MYTabbyViewController : UITabBarController

@end

实施

#import "MYTabbyViewController.h"

@implementation MYTabbyViewController

-(void)setSelectedViewController:(UIViewController *)selectedViewController
{
    [super setSelectedViewController:selectedViewController];

    for (UIViewController *viewController in self.viewControllers) {
        if (viewController == selectedViewController) {
            [viewController.tabBarItem setTitleTextAttributes:@{
                                                    NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue-Medium" size:16],
                                                    NSForegroundColorAttributeName: [UIColor blueColor]
                                                    }
                                         forState:UIControlStateNormal];
        } else {
            [viewController.tabBarItem setTitleTextAttributes:@{
                                                    NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue-Light" size:16],
                                                    NSForegroundColorAttributeName: [UIColor grayColor]
                                                    }
                                         forState:UIControlStateNormal];
        }
    }
}

您需要的最后一部分是使用这个子类而不是开箱即用的 UITabBarController。如果您使用 Storyboards，只需选择 TabBarController，转到 Identity Inspector（右侧面板中的第三个子选项卡）并将 UITabBarController 更改为 MYTabBarController 或你有什么。

但是是的！最重要的是，只需更新 ViewController tabBarItem！

Answer 2

@Acey 在 Swift 3 中的回答：

    override var selectedViewController: UIViewController? {
    didSet {

        guard let viewControllers = viewControllers else {
            return
        }

        for viewController in viewControllers {

            if viewController == selectedViewController {

                let selected: [String: AnyObject] =
                    [NSFontAttributeName: UIFont.systemFont(ofSize: 11, weight: UIFontWeightHeavy),
                     NSForegroundColorAttributeName: UIColor.red]

                viewController.tabBarItem.setTitleTextAttributes(selected, for: .normal)

            } else {

                let normal: [String: AnyObject] =
                    [NSFontAttributeName: UIFont.systemFont(ofSize: 11),
                     NSForegroundColorAttributeName: UIColor.blue]

                viewController.tabBarItem.setTitleTextAttributes(normal, for: .normal)

            }
        }
    }
}

Answer 3

@Acey's Answer 几乎是完美的，但仅在您第一次选择 tabBarItem 后才更改字体，因此当创建 tabBar 时，将在该时刻为所选的 tabBarItem 创建没有不同的字体。为此，我还在selectedIndex 变量中添加了didSet。

这是完整代码 (Swift 4.2)

final class TabBarController: UITabBarController {

override var selectedIndex: Int {
    didSet {
        guard let selectedViewController = viewControllers?[selectedIndex] else {
            return
        }
        selectedViewController.tabBarItem.setTitleTextAttributes([.font: UIFont.systemFont(ofSize: 11, weight: UIFontWeightHeavy)], for: .normal)
    }
}

override var selectedViewController: UIViewController? {
    didSet {

        guard let viewControllers = viewControllers else {
            return
        }

        for viewController in viewControllers {

            if viewController == selectedViewController {

                let selected: [NSAttributedString.Key: AnyObject] =
                    [.font: UIFont.systemFont(ofSize: 11, weight: UIFontWeightHeavy)]

                viewController.tabBarItem.setTitleTextAttributes(selected, for: .normal)

            } else {

                let normal: [NSAttributedString.Key: AnyObject] =
                    [.font: UIFont.systemFont(ofSize: 11)]

                viewController.tabBarItem.setTitleTextAttributes(normal, for: .normal)

            }
        }
    }
}

}

Answer 4

setSelected 和 setHighlighted 不适用于 UIBarButtonItems。

使用 UIBarButtonItem 的

- (void)setBackgroundImage:(UIImage *)backgroundImage forState:(UIControlState)state barMetrics:(UIBarMetrics)barMetrics 

这是文档 - https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIBarButtonItem_Class/Reference/Reference.html

或者，使用 UIButton。

UIButton *myButton = [UIButton buttonWithType: UIButtonTypeRoundedRect];
[myButton setTitle:@"Info" forState:UIControlStateNormal];
[myButton setFont:[UIFont fontWithName:<font name> size:<font size>]];

[myButton setTitleColor:<color>;
myButton =  <frame>;
[myButton addTarget:self.webView action:@selector(<action>:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem * barButtonItem = [[UIBarButtonItem alloc]initWithCustomView:myButton];
[[UIBarButtonItem appearance] setTintColor:<color>;
[self.toolbar setItems:[NSArray arrayWithObjects: spaceItem, barButtonItem, nil]];