變化斯威夫特

Question

AttributedText的只是字體我有一些在IB創建UILabels這一切都已歸於文本。每個標籤的文本都包含多行不同字體大小和顏色。

在運行時，我希望能夠在不更改現有字體大小或顏色的情況下更改這些標籤的字體名稱。

我已經研究過，無法找到一個簡單的方法來實現這一點。有任何想法嗎？

Answer 1

你首先需要了解蘋果公司用來描述字體的行話

• Helvetica是家庭
• Helvetica Bold，Helvetica Italic，Helvetica Bold Italic，Helvetica Display等都是面臨
• Helvetica Bold, 12pt是一個字體

你需要的是更換一個屬性串的字體家族：

let newAttributedString = NSMutableAttributedString(attributedString: label.attributedText) 

// Enumerate through all the font ranges 
newAttributedString.enumerateAttribute(NSFontAttributeName, in: NSMakeRange(0, newAttributedString.length), options: []) { value, range, stop in 
    guard let currentFont = value as? UIFont else { 
     return 
    } 

    // An NSFontDescriptor describes the attributes of a font: family name, face name, point size, etc. 
    // Here we describe the replacement font as coming from the "Hoefler Text" family 
    let fontDescriptor = currentFont.fontDescriptor.addingAttributes([UIFontDescriptorFamilyAttribute: "Hoefler Text"]) 

    // Ask the OS for an actual font that most closely matches the description above 
    if let newFontDescriptor = fontDescriptor.matchingFontDescriptors(withMandatoryKeys: [UIFontDescriptorFamilyAttribute]).first { 
     let newFont = UIFont(descriptor: newFontDescriptor, size: currentFont.pointSize) 
     newAttributedString.addAttributes([NSFontAttributeName: newFont], range: range) 
    } 
} 

label.attributedText = newAttributedString 

原件（舊金山）：

更換（Hoefler文本）：

Answer 2

以上的偉大工程，但與Swift4和9.1的Xcode我得到這個方法的名字改變了警告的數量。以下是應用所有這些警告的結果。否則，我沒有改變任何東西。

let newAttributedString = NSMutableAttributedString(attributedString: label.attributedText!) 

// Enumerate through all the font ranges 
newAttributedString.enumerateAttribute(NSAttributedStringKey.font, in: NSMakeRange(0, newAttributedString.length), options: []) 
{ 
    value, range, stop in 
    guard let currentFont = value as? UIFont else { 
     return 
    } 

    // An NSFontDescriptor describes the attributes of a font: family name, face name, point size, etc. 
    // Here we describe the replacement font as coming from the "Hoefler Text" family 
    let fontDescriptor = currentFont.fontDescriptor.addingAttributes([UIFontDescriptor.AttributeName.family: "Hoefler Text"]) 

    // Ask the OS for an actual font that most closely matches the description above 
    if let newFontDescriptor = fontDescriptor.matchingFontDescriptors(withMandatoryKeys: [UIFontDescriptor.AttributeName.family]).first { 
     let newFont = UIFont(descriptor: newFontDescriptor, size: currentFont.pointSize) 
     newAttributedString.addAttributes([NSAttributedStringKey.font: newFont], range: range) 
    } 
} 

label.attributedText = newAttributedString