使用swift Xcode 6的默认选项卡栏项目颜色

Question

环境：-Xcode 6 beta 4-Swift语言-iOS选项卡式应用程序（默认Xcode项目）

如何将选项卡的默认灰色更改为其他颜色？（最好是在全球范围内）

就我的研究而言，我需要以某种方式将每个选项卡的图像渲染模式更改为原始渲染模式，但我不知道如何更改

Answer 1

斯威夫特2.0

要更改选项卡栏图像的默认颜色，请将下面的代码添加到TabBarController类的viewDidLoad方法：

for item in self.tabBar.items! as [UITabBarItem] {
    if let image = item.image {
      item.image = image.imageWithColor(UIColor.yellowColor()).imageWithRenderingMode(.AlwaysOriginal)
    }
}

更新Imagewith Color扩展。与上述方法一起使用，并且应该放在您的TabBarController类之外：

extension UIImage {
    func imageWithColor(tintColor: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)

        let context = UIGraphicsGetCurrentContext()! as CGContextRef
        CGContextTranslateCTM(context, 0, self.size.height)
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, CGBlendMode.Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect
        CGContextClipToMask(context, rect, self.CGImage)
        tintColor.setFill()
        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext() as UIImage
        UIGraphicsEndImageContext()

        return newImage
    }
}

没有改变文本的着色方式，但仅供参考。还应该添加下面的代码到viewddLoad：

// you can add this code to you AppDelegate application:didFinishLaunchingWithOptions: 
// or add it to viewDidLoad method of your TabBarController class
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.magentaColor()], forState:.Normal)
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.redColor()], forState:.Selected)

Answer 2

匿名用户

我没有足够的声誉评论的评论但许多人有兴趣如何改变所选图像的颜色

如果让检查，只需添加另一个

if let image = item.image

就像这样：

if let selectedImage = item.selectedImage {
            item.selectedImage = selectedImage.imageWithColor(UIColor.yellowColor()).imageWithRenderingMode(.AlwaysOriginal)
        }

这完美地解决了这个问题。还有一点补充，因为你需要Swift 1.2和Xcode 6.3.2

for item in self.tabBar.items as! [UITabBarItem]

而不是

for item in self.tabBar.items as [UITabBarItem]

希望这有帮助！

Answer 3

每个（默认）标签栏项由文本和图标组成。通过指定外观，可以很容易地全局更改文本颜色：

// you can add this code to you AppDelegate application:didFinishLaunchingWithOptions: 
// or add it to viewDidLoad method of your TabBarController class
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.magentaColor()], forState:.Normal)
UITabBarItem.appearance().setTitleTextAttributes([NSForegroundColorAttributeName: UIColor.redColor()], forState:.Selected)

有了图像，情况就复杂了一点。不能全局定义它们的外观。您应该在TabBarController类中重新定义它们。将下面的代码添加到TabBarController类的viewDidLoad方法：

for item in self.tabBar.items as [UITabBarItem] {
    if let image = item.image {
        item.image = image.imageWithColor(UIColor.yellowColor()).imageWithRenderingMode(.AlwaysOriginal)
    }
}

正如我们所知，imageWithColor（…）方法。下面是扩展实现：

// Add anywhere in your app
extension UIImage {
    func imageWithColor(tintColor: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)

        let context = UIGraphicsGetCurrentContext() as CGContextRef
        CGContextTranslateCTM(context, 0, self.size.height)
        CGContextScaleCTM(context, 1.0, -1.0);
        CGContextSetBlendMode(context, .Normal)

        let rect = CGRectMake(0, 0, self.size.width, self.size.height) as CGRect
        CGContextClipToMask(context, rect, self.CGImage)
        tintColor.setFill()
        CGContextFillRect(context, rect)

        let newImage = UIGraphicsGetImageFromCurrentImageContext() as UIImage
        UIGraphicsEndImageContext()

        return newImage
    }
}

Imagewith Color借用了这个答案：https://stackoverflow.com/a/24545102/3050466