用另一个 NSAttributedString 替换 NSAttributedString 的子字符串

Question

我想用另一个NSAttributedString 替换NSAttributedString 的子字符串（例如@"replace"）。

我正在为NSAttributedString 寻找与NSString 的stringByReplacingOccurrencesOfString:withString: 等效的方法。

Answer 1

1. 将属性字符串转换为NSMutableAttributedString 的实例。

2. 可变属性字符串具有mutableString 属性。根据文档：

   “接收者跟踪此字符串的更改并保持其属性映射是最新的。”

   因此，您可以使用生成的可变字符串以replaceOccurrencesOfString:withString:options:range: 执行替换。

Answer 2

以下是如何更改 NSMutableAttributedString 的字符串，同时保留其属性：

斯威夫特：

// first we create a mutable copy of attributed text 
let originalAttributedText = nameLabel.attributedText?.mutableCopy() as! NSMutableAttributedString

// then we replace text so easily
let newAttributedText = originalAttributedText.mutableString.setString("new text to replace")

目标-C：

NSMutableAttributedString *newAttrStr = [attribtedTxt.mutableString setString:@"new string"];

Answer 3

NSMutableAttributedString *result = [[NSMutableAttributedString alloc] initWithString:@"I am a boy."];
[result addAttribute:NSForegroundColorAttributeName value:[UIColor blackColor] range:NSMakeRange(0, [result length])];

NSMutableAttributedString *replace = [[NSMutableAttributedString alloc] initWithString:@"a"];
[replace addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, [replace length])];

[result replaceCharactersInRange:NSMakeRange(5, [replace length]) withAttributedString:replace];

Answer 4

我必须在<b> 标签中加粗文本，我做了什么：

- (NSAttributedString *)boldString:(NSString *)string {
    UIFont *boldFont = [UIFont boldSystemFontOfSize:14];
    NSMutableAttributedString *attributedDescription = [[NSMutableAttributedString alloc] initWithString:string];

    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@".*?<b>(.*?)<\\/b>.*?" options:NSRegularExpressionCaseInsensitive error:NULL];
    NSArray *myArray = [regex matchesInString:string options:0 range:NSMakeRange(0, string.length)] ;
    for (NSTextCheckingResult *match in myArray) {
        NSRange matchRange = [match rangeAtIndex:1];
        [attributedDescription addAttribute:NSFontAttributeName value:boldFont range:matchRange];
    }
    while ([attributedDescription.string containsString:@"<b>"] || [attributedDescription.string containsString:@"</b>"]) {
        NSRange rangeOfTag = [attributedDescription.string rangeOfString:@"<b>"];
        [attributedDescription replaceCharactersInRange:rangeOfTag withString:@""];
        rangeOfTag = [attributedDescription.string rangeOfString:@"</b>"];
        [attributedDescription replaceCharactersInRange:rangeOfTag withString:@""];
    }
    return attributedDescription;
}

Answer 5

就我而言，以下方式是唯一的（在 iOS9 上测试）：

NSAttributedString *attributedString = ...;
NSAttributedString *anotherAttributedString = ...; //the string which will replace

while ([attributedString.mutableString containsString:@"replace"]) {
        NSRange range = [attributedString.mutableString rangeOfString:@"replace"];
        [attributedString replaceCharactersInRange:range  withAttributedString:anotherAttributedString];
    }

当然，如果能找到另一种更好的方法就好了。

Answer 6

我发现所有其他答案都不起作用。以下是我如何在类别扩展中替换 NSAttributed 字符串的内容：

func stringWithString(stringToReplace:String, replacedWithString newStringPart:String) -> NSMutableAttributedString
{
    let mutableAttributedString = mutableCopy() as! NSMutableAttributedString
    let mutableString = mutableAttributedString.mutableString

    while mutableString.containsString(stringToReplace) {
        let rangeOfStringToBeReplaced = mutableString.rangeOfString(stringToReplace)
        mutableAttributedString.replaceCharactersInRange(rangeOfStringToBeReplaced, withString: newStringPart)
    }
    return mutableAttributedString
}

Answer 7

在 Swift 4 和 iOS 11 中，您可以使用以下两种方法之一来解决您的问题。

---

#1。使用NSMutableAttributedStringreplaceCharacters(in:with:)方法

NSMutableAttributedString 有一个名为replaceCharacters(in:with:) 的方法。 replaceCharacters(in:with:) 有以下声明：

用给定属性字符串的字符和属性替换给定范围内的字符和属性。

func replaceCharacters(in range: NSRange, with attrString: NSAttributedString)

下面的 Playground 代码展示了如何使用 replaceCharacters(in:with:) 来将 NSMutableAttributedString 实例的子字符串替换为新的 NSMutableAttributedString 实例：

import UIKit

// Set initial attributed string
let initialString = "This is the initial string"
let attributes = [NSAttributedStringKey.foregroundColor : UIColor.red]
let mutableAttributedString = NSMutableAttributedString(string: initialString, attributes: attributes)

// Set new attributed string
let newString = "new"
let newAttributes = [NSAttributedStringKey.underlineStyle : NSUnderlineStyle.styleSingle.rawValue]
let newAttributedString = NSMutableAttributedString(string: newString, attributes: newAttributes)

// Get range of text to replace
guard let range = mutableAttributedString.string.range(of: "initial") else { exit(0) }
let nsRange = NSRange(range, in: mutableAttributedString.string)

// Replace content in range with the new content
mutableAttributedString.replaceCharacters(in: nsRange, with: newAttributedString)

---

#2。使用NSMutableStringreplaceOccurrences(of:with:options:range:)方法

NSMutableString 有一个名为replaceOccurrences(of:with:options:range:) 的方法。 replaceOccurrences(of:with:options:range:) 有以下声明：

用另一个给定字符串替换给定范围内所有出现的给定字符串，返回替换次数。

func replaceOccurrences(of target: String, with replacement: String, options: NSString.CompareOptions = [], range searchRange: NSRange) -> Int

下面的 Playground 代码展示了如何使用 replaceOccurrences(of:with:options:range:) 来将 NSMutableAttributedString 实例的子字符串替换为新的 NSMutableAttributedString 实例：

import UIKit

// Set initial attributed string
let initialString = "This is the initial string"
let attributes = [NSAttributedStringKey.foregroundColor : UIColor.red]
let mutableAttributedString = NSMutableAttributedString(string: initialString, attributes: attributes)

// Set new string
let newString = "new"

// Replace replaceable content in mutableAttributedString with new content
let totalRange = NSRange(location: 0, length: mutableAttributedString.string.count)
_ = mutableAttributedString.mutableString.replaceOccurrences(of: "initial", with: newString, options: [], range: totalRange)

// Get range of text that requires new attributes
guard let range = mutableAttributedString.string.range(of: newString) else { exit(0) }
let nsRange = NSRange(range, in: mutableAttributedString.string)

// Apply new attributes to the text matching the range
let newAttributes = [NSAttributedStringKey.underlineStyle : NSUnderlineStyle.styleSingle.rawValue]
mutableAttributedString.setAttributes(newAttributes, range: nsRange)

Answer 8

我有一个特定的要求并固定如下。这可能会对某人有所帮助。

要求： 在storyboard中，直接将富文本添加到UITextView的属性中，其中包含一个单词“App Version: 1.0”。现在我必须通过从 info plist 中读取来动态化版本号。

解决方案： 从情节提要中删除版本号 1.0，只保留“App Version:”并添加以下代码。

NSAttributedString *attribute = self.firsttextView.attributedText;
NSMutableAttributedString *mutableAttri = [[NSMutableAttributedString alloc] initWithAttributedString:attribute];
NSString *appVersionText = @"App Version:";
if ([[mutableAttri mutableString] containsString:appVersionText]) {
    NSDictionary* infoDict = [[NSBundle mainBundle] infoDictionary];
    NSString* version = [infoDict objectForKey:@"CFBundleShortVersionString"];
    NSString *newappversion = [NSString stringWithFormat:@"%@ %@",appVersionText,version] ;
    [[mutableAttri mutableString] replaceOccurrencesOfString:appVersionText withString:newappversion options:NSCaseInsensitiveSearch range:NSMakeRange(0, mutableAttri.length)];
    self.firsttextView.attributedText = mutableAttri;
}

完成！！更新/修改了属性文本。

Answer 9

斯威夫特 4： 更新了sunkas Swift 4 的优秀解决方案并包含在“扩展”中。只需将它剪辑到您的 ViewController（在类之外）并使用它。

extension NSAttributedString {
    func stringWithString(stringToReplace: String, replacedWithString newStringPart: String) -> NSMutableAttributedString
    {
        let mutableAttributedString = mutableCopy() as! NSMutableAttributedString
        let mutableString = mutableAttributedString.mutableString
        while mutableString.contains(stringToReplace) {
            let rangeOfStringToBeReplaced = mutableString.range(of: stringToReplace)
            mutableAttributedString.replaceCharacters(in: rangeOfStringToBeReplaced, with: newStringPart)
        }
        return mutableAttributedString
    }
}