ios11- UIFont返回零

Question

我正在使用UIFont更改我的应用程序中的默认字体。代码在iOS 10及更低版本上工作正常，但它在iOS 11上返回nil，没有任何改变。我正在使用swift 4

这是我返回nil的代码：

UIFont(name: "AIranianSans", size: 20)

你可以帮帮我吗 ？怎么了 ？

Answer 1

尝试检查可用的字体

for familyName:String in UIFont.familyNames {
    print("Family Name: \(familyName)")
    for fontName:String in UIFont.fontNames(forFamilyName: familyName) {
         print("--Font Name: \(fontName)")
     }
}

可能是字体拼写不同。

Answer 2

它看起来像一个自定义字体，您必须在XCode中添加为资源。当您通过拖放包含资源时，XCode 9存在一个未向目标添加资源的已知问题。

检查文件inspector.中.ttf文件的目标成员身份

Answer 3

https://codewithchris.com/common-mistakes-with-adding-custom-fonts-to-your-ios-app/在这里提到以下步骤之后，我无法在运行时在swift4中加载应用程序中的字体。当我们在故事板中应用特定的自定义字体时，字体将在运行时出现。然后只有这个API

UIFont(name: "font name", size: 20.0) 

返回字体实例，否则它将仅返回nil。所以设计时自定义字体工作正常但不是运行时

要运行运行时我们需要加载字体

加载您喜欢的字体文件

UIFont.registerFontWithFilenameString(filenameString: "font 1 Sans LF Bold.ttf", bundle: Bundle.main)
        UIFont.registerFontWithFilenameString(filenameString: "font 2Sans LF Light.ttf", bundle: Bundle.main)
        UIFont.registerFontWithFilenameString(filenameString: "font 3Sans LF Regular.ttf", bundle: Bundle.main)
        UIFont.registerFontWithFilenameString(filenameString: "font 4Sans LF Medium.ttf", bundle: Bundle.main)

public static func registerFontWithFilenameString（filenameString：String，bundle：Bundle）{

    guard let pathForResourceString = bundle.path(forResource: filenameString, ofType: nil) else {
        print("UIFont+:  Failed to register font - path for resource not found.")
        return
    }

    guard let fontData = NSData(contentsOfFile: pathForResourceString) else {
        print("UIFont+:  Failed to register font - font data could not be loaded.")
        return
    }

    guard let dataProvider = CGDataProvider(data: fontData) else {
        print("UIFont+:  Failed to register font - data provider could not be loaded.")
        return
    }

    guard let fontRef = CGFont(dataProvider) else {
        print("UIFont+:  Failed to register font - font could not be loaded.")
        return
    }

    var errorRef: Unmanaged<CFError>? = nil
    if (CTFontManagerRegisterGraphicsFont(fontRef, &errorRef) == false) {
        print("UIFont+:  Failed to register font - register graphics font failed - this font may have already been registered in the main bundle.")
    }

代码采取Xcode: Using custom fonts inside Dynamic framework