在Swift for iOS中将TabBarItem标题字体更改为粗体

概述我正在尝试将所选标签栏项的字体粗细设置为粗体字体.似乎它没有任何效果.知道什么是错的. forState：.Normal按预期工作,对于State：.Selected无效. let tabBarItem0 = tabBar.items![0] as! UITabBarItemvar selectedImage0 : UIImage = UIImage(named:"ic_tabbar_item_ 我正在尝试将所选标签栏项的字体粗细设置为粗体字体.似乎它没有任何效果.知道什么是错的. forState：.normal按预期工作,对于State：.Selected无效.

let tabbarItem0 = tabbar.items![0] as! UITabbarItemvar selectedImage0 : UIImage = UIImage(named:"ic_tabbar_item_one")!.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal)var Fontlight:UIFont = UIFont(name: "HelveticaNeue-ultralight",size: 12)!var FontBold:UIFont = UIFont(name: "HelveticaNeue-Bold",size: 12)!tabbarItem0.image = unselectedImage0tabbarItem0.selectedImage = selectedImage0tabbarItem0.Title = "OvervIEw"tabbarItem0.setTitleTextAttributes(    [        NSForegroundcolorAttributename: UIcolor.whitecolor(),NSFontAttributename: Fontlight    ],forState: .normal)tabbarItem0.setTitleTextAttributes(    [        NSForegroundcolorAttributename: UIcolor.whitecolor(),NSFontAttributename: FontBold    ],forState: UIControlState.Selected)

发现解决方案(Swift 3,XCode 8.1)

>在Storyboard中,为每个UITabbarItem提供一个唯一的标记：对于每个标签 – >选择它并转到它的“属性检查器” – >在“标签”字段中为每个人提供一个唯一的编号,但不应使用零(我使用1到4).

这为我们稍后设置,以确定按下哪个选项卡.

>创建一个新的UITabbarController子类,然后分配它：file – >新文件 – > iOS Cocoa touch – >创建一个UITabbarController的子类.将新的.swift文件分配给您的.swift文件
“IDentity Inspector”下的UITabbarController.

我们需要在UITabbarController中使用自定义逻辑.

>创建UITabbarItem的新子类,将相同的文件分配给所有UITabbarItem：file – >新文件 – > iOS Cocoa touch – >创建一个UITabbarItem的子类,并为所有选项卡分配相同的子类.

我们的标签栏项目中需要共享的自定义逻辑.

>将此代码添加到UITabbarItem子类,它设置初始状态(主选项卡粗体,其余未选中),并允许编程选项卡更改：

class MyUITabbarItemSubclass: UITabbarItem {    //choose initial state Fonts and weights here    let normalTitleFont = UIFont.systemFont(ofSize: 12,weight: UIFontWeightRegular)     let selectedTitleFont = UIFont.systemFont(ofSize: 12,weight: UIFontWeightBold)    //choose initial state colors here    let normalTitlecolor = UIcolor.gray     let selectedTitlecolor = UIcolor.black    //assigns the proper initial state logic when each tab instantiates     overrIDe func awakeFromNib() {        super.awakeFromNib()        //this tag # should be your primary tab's Tag*         if self.tag == 1 {             self.setTitleTextAttributes([NSFontAttributename: selectedTitleFont,NSForegroundcolorAttributename: selectedTitlecolor],for: UIControlState.normal)        } else {            self.setTitleTextAttributes([NSFontAttributename: normalTitleFont,NSForegroundcolorAttributename: normalTitlecolor],for: UIControlState.normal)        }    }}

这里我们设置初始状态,以便在应用程序打开时正确设置选项卡,我们将在下一个子类中处理物理选项卡.

>将此代码添加到UITabbarController子类中,这是在按下选项卡时分配正确状态的逻辑.

class MyUITabbarControllerSubclass: UITabbarController {    //choose normal and selected Fonts here    let normalTitleFont = UIFont.systemFont(ofSize: 12,weight: UIFontWeightRegular)    let selectedTitleFont = UIFont.systemFont(ofSize: 12,weight: UIFontWeightBold)    //choose normal and selected colors here    let normalTitlecolor = UIcolor.gray    let selectedTitlecolor = UIcolor.black    //the following is a delegate method from the UITabbar protocol that's available     //to UITabbarController automatically. It sends us information every    //time a tab is pressed. Since we Tagged our tabs earlIEr,we'll kNow which one was pressed,//and pass that IDentifIEr into a function to set our button states for us    overrIDe func tabbar(_ tabbar: UITabbar,dIDSelect item: UITabbarItem) {        setbuttonStates(itemTag: item.tag)    }    //the function takes the tabbar.tag as an Int    func setbuttonStates (itemTag: Int) {        //making an array of all the tabs        let tabs = self.tabbar.items        //looPing through and setting the states        var x = 0        while x < (tabs?.count)! {            if tabs?[x].tag == itemTag {                tabs?[x].setTitleTextAttributes([NSFontAttributename: selectedTitleFont,for: UIControlState.normal)            } else {                tabs?[x].setTitleTextAttributes([NSFontAttributename: normalTitleFont,for: UIControlState.normal)            }            x += 1        }    }}

看起来这很痛苦,因为由于某种原因,标签不能将状态变化识别为“.Selected”.我们必须通过仅使用.normal状态来做所有事情 – 基本上自己检测状态变化.

>您可以通过编程方式更改选项卡并仍然通过…检测状态更改.如果有人有兴趣,我会稍后更新,只需询问.

希望这有帮助！

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