appendAttributedString return 类型为 Void 的值

Question

我正在尝试附加两个 NSAttributedString。

let string_1 : NSAttributedString = self.answerTextView.attributedText
let string_2 : NSAttributedString = handleHtml(i) // a function that returns a NSAttributedString
let finalStr : NSAttributedString = string_1.mutableCopy().appendAttributedString(string_2)

但是我在第三行出错了:

Cannot convert value of type 'Void' (aka '()') to specified type 'NSAttributedString'

我该如何解决这个问题？谢谢

Answer 1

appendAttributedString 更新调用者。它不是 return 新字符串。尝试以下操作：

let string_1 : NSAttributedString = self.answerTextView.attributedText
let string_2 : NSAttributedString = handleHtml(i) // a function that returns a NSAttributedString
let tmpStr : NSMutableAttributedString = string_1.mutableCopy()
tmpStr.appendAttributedString(string_2)
let finalStr : NSAttributedString = tmpStr.copy()

Answer 2

定义如下：

//MARK: Custom functions
func getQueueAttributedString(number N: Int) -> NSAttributedString? {

    let uploadSymbolAttributes = [NSForegroundColorAttributeName: UEColor.brown.six, NSFontAttributeName: UEFont.unearthCharacterFont(13)]

    let attributedString = NSMutableAttributedString(string: UEFontCharacter.triangle_up, attributes: uploadSymbolAttributes)

    let queueAttributes = [NSForegroundColorAttributeName: UEColor.brown.six, NSFontAttributeName: UEFont.museo300(withSize: 13)]

    let queueString = NSAttributedString(string: " \(N) items queued", attributes: queueAttributes)

    attributedString.append(queueString)

    return attributedString

}

其中 UEFont 是自定义 UIFont，UEColor 是自定义 UIColor 的静态结构，UEFontCharacter 是线性图标字体。

appendAttributedString return 类型为 Void 的值

appendAttributedString return value of type Void

nsattributedstring

ios

swift