Question

我遇到了一个问题，下面的代码不仅用secondString替换firstString，而且在句子前面放了secondString。我的问题是如何替换这个firstString？替换字符是正确的方法吗？

class ViewController: UIViewController {

@IBOutlet weak var textView: UITextView!
let firstString: String = "xxx"
let secondString: String = "yyy"


    override func viewDidLoad() {
        super.viewDidLoad()
        textView.text = "this \(firstString) is an example of a sentence"
    }

    func replace() {
        var finalString: String?
        let range = firstString.startIndex..<firstString.endIndex
        print(firstString[range])

        finalString = textView.text.replacingCharacters(in: range, with: secondString)
        textView.text = finalString
    }

    @IBAction func replaceButton(_ sender: Any) {
    replace()
    }

}

Answer 1

如果您只需要替换firstString的任何匹配项，那么您应该使用：replacingOccurrences(of:with:)，如下所示：

textView.text.replacingCharacters(of: firstString, with: secondString)

以及你遇到secondString在句子前面的问题的原因是因为在你的替换方法中：

func replace() {
    var finalString: String?
    let range = firstString.startIndex..<firstString.endIndex
    print(firstString[range])

    finalString = textView.text.replacingCharacters(in: range, with: secondString)
    textView.text = finalString
}

你正试图获得firstString的范围：

let range = firstString.startIndex..<firstString.endIndex

并尝试将该范围应用于textview的字符串，这是与firstString完全不同的字符串，因此您提供的范围不是您想要的范围。您的firstString和textview文本不同，因此它们将具有不同的范围，将一个字符串的范围值与另一个字符串一起使用是不合适的

修改如果你真的想通过查找/使用范围来替换字符串，那么你需要首先检测你想要替换文本的范围是什么，这意味着在你的textview文本中

＆＃34;这个（firstString）是一个句子的例子＆＃34;

您需要通过替换来找到该句子中的范围firstString：

let range = firstString.startIndex..<firstString.endIndex

与

let range = textView.text.range(of: firstString)

func range(of searchString: String) -> NSRange将＆＃34;查找并返回接收器中给定字符串第一次出现的范围。＆＃34;根据Apple的文件：https://developer.apple.com/documentation/foundation/nsstring/1410144-range

Answer 2

实现目标的最简单方法，

textview.text?.replacingOccurrences(of: firstString, with: secondString)

Answer 3

如果您想将字替换为另一个字，那么您应该使用replacingOccurrences(of:with:)方法：

返回一个新字符串，其中出现所有目标字符串接收器被另一个给定的字符串替换。

举个例子：

let originalString = "I live in Paris"

let updatedString = originalString.replacingOccurrences(of: "Paris", with: "New-York")

print(updatedString) // Prints "I live in New-York"

在你的情况下，你会有类似的东西：

class ViewController: UIViewController {

    // MARK: @IBOutlets

    @IBOutlet weak var textView: UITextView!

    // MARK: Properties

    let firstString: String = "pink"
    let secondString: String = "blue"

    // MARK: Life Cycle

    override func viewDidLoad() {
        super.viewDidLoad()

        textView.text = "The sky is \(firstString)"
        print(textView.text) // Prints "The sky is pink"
    }

    // MARK: User Interaction

    @IBAction func replaceButton(_ sender: Any) {

        let originalString = textView.text

        let updatedString = originalString.replacingOccurrences(of: firstString, with: secondString)

        print(updatedString) // Prints "The sky is blue"

        // Now you can set your text view's text to be equal to your updated string if you want :

        textView.text = updatedString

    }

}

Answer 4

class ViewController: UIViewController 
{
 @IBOutlet weak var textView: UITextView!
    let firstString: String = "xxx"
    let secondString: String = "yyy"
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        textView.text = "this \(firstString) is an example of a sentence"

    }
    func replace() {
       var finalString: String?
       let originalString = textView.text
       finalString = originalString?.replacingOccurrences(of: 
firstString, with: secondString)
       textView.text = finalString
    }

    @IBAction func replaceButton(_ sender: Any) {
        replace()
    }
}

如何在UITextView中替换句子中的确切关键字

4 个答案: