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! UITabBarItem
var 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 = unselectedImage0
tabBarItem0.selectedImage = selectedImage0
tabBarItem0.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.
>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！
