ios - How can I concatenate NSAttributedStrings?

Question

I need to search some strings and set some attributes prior to merging the strings, so having NSStrings -> Concatenate them -> Make NSAttributedString is not an option, is there any way to concatenate attributedString to another attributedString?

Answer 1

我建议您使用@Linuxios 建议的单个可变属性字符串，这是另一个示例：

NSMutableAttributedString *mutableAttString = [[NSMutableAttributedString alloc] init];

NSString *plainString = // ...
NSDictionary *attributes = // ... a dictionary with your attributes.
NSAttributedString *newAttString = [[NSAttributedString alloc] initWithString:plainString attributes:attributes];

[mutableAttString appendAttributedString:newAttString];

但是，只是为了获得所有选项，您还可以创建一个可变属性字符串，该字符串由格式化的 NSString 组成，其中包含已经放在一起的输入字符串。然后，您可以addAttributes: range:在事后将属性添加到包含输入字符串的范围中。我推荐前一种方式。

Answer 2

如果您使用的是 Swift，您可以重载+运算符，以便您可以像连接普通字符串一样连接它们：

// concatenate attributed strings
func + (left: NSAttributedString, right: NSAttributedString) -> NSAttributedString
{
    let result = NSMutableAttributedString()
    result.append(left)
    result.append(right)
    return result
}

现在您可以通过添加它们来连接它们：

let helloworld = NSAttributedString(string: "Hello ") + NSAttributedString(string: "World")

Answer 3

Swift 3：只需创建一个 NSMutableAttributedString 并将属性字符串附加到它们。

let mutableAttributedString = NSMutableAttributedString()

let boldAttribute = [
    NSFontAttributeName: UIFont(name: "GothamPro-Medium", size: 13)!,
    NSForegroundColorAttributeName: Constants.defaultBlackColor
]

let regularAttribute = [
    NSFontAttributeName: UIFont(name: "Gotham Pro", size: 13)!,
    NSForegroundColorAttributeName: Constants.defaultBlackColor
]

let boldAttributedString = NSAttributedString(string: "Warning: ", attributes: boldAttribute)
let regularAttributedString = NSAttributedString(string: "All tasks within this project will be deleted.  If you're sure you want to delete all tasks and this project, type DELETE to confirm.", attributes: regularAttribute)
mutableAttributedString.append(boldAttributedString)
mutableAttributedString.append(regularAttributedString)

descriptionTextView.attributedText = mutableAttributedString

swift5更新：

    let captionAttribute = [
        NSAttributedString.Key.font: Font.captionsRegular,
        NSAttributedString.Key.foregroundColor: UIColor.appGray
    ]

Answer 4

尝试这个：

NSMutableAttributedString* result = [astring1 mutableCopy];
[result appendAttributedString:astring2];

在哪里astring1和astring2是NSAttributedStrings。

Answer 5

2020 | 斯威夫特 5.1：

您可以NSMutableAttributedString通过以下方式添加 2：

let concatenated = NSAttrStr1.append(NSAttrStr2)

另一种方法适用于NSMutableAttributedString两者NSAttributedString：

[NSAttrStr1, NSAttrStr2].joinWith(separator: "")

---

另一种方法是......

var full = NSAttrStr1 + NSAttrStr2 + NSAttrStr3

和：

var full = NSMutableAttributedString(string: "hello ")
// NSAttrStr1 == 1


full += NSAttrStr1 // full == "hello 1"       
full += " world"   // full == "hello 1 world"

您可以使用以下扩展名执行此操作：

// works with NSAttributedString and NSMutableAttributedString!
public extension NSAttributedString {
    static func + (left: NSAttributedString, right: NSAttributedString) -> NSAttributedString {
        let leftCopy = NSMutableAttributedString(attributedString: left)
        leftCopy.append(right)
        return leftCopy
    }

    static func + (left: NSAttributedString, right: String) -> NSAttributedString {
        let leftCopy = NSMutableAttributedString(attributedString: left)
        let rightAttr = NSMutableAttributedString(string: right)
        leftCopy.append(rightAttr)
        return leftCopy
    }

    static func + (left: String, right: NSAttributedString) -> NSAttributedString {
        let leftAttr = NSMutableAttributedString(string: left)
        leftAttr.append(right)
        return leftAttr
    }
}

public extension NSMutableAttributedString {
    static func += (left: NSMutableAttributedString, right: String) -> NSMutableAttributedString {
        let rightAttr = NSMutableAttributedString(string: right)
        left.append(rightAttr)
        return left
    }

    static func += (left: NSMutableAttributedString, right: NSAttributedString) -> NSMutableAttributedString {
        left.append(right)
        return left
    }
}

Answer 6

如果您使用的是 Cocoapods，则上述两个答案的替代方法可以让您避免自己代码中的可变性，即在 s 上使用出色的NSAttributedString+CCLFormat类别NSAttributedString，让您可以编写如下内容：

NSAttributedString *first = ...;
NSAttributedString *second = ...;
NSAttributedString *combined = [NSAttributedString attributedStringWithFormat:@"%@%@", first, second];

它当然只是NSMutableAttributedString在幕后使用。

它还具有一个完全成熟的格式化功能的额外优势——因此它可以做的不仅仅是将字符串附加在一起。

Answer 7

// Immutable approach
// class method

+ (NSAttributedString *)stringByAppendingString:(NSAttributedString *)append toString:(NSAttributedString *)string {
  NSMutableAttributedString *result = [string mutableCopy];
  [result appendAttributedString:append];
  NSAttributedString *copy = [result copy];
  return copy;
}

//Instance method
- (NSAttributedString *)stringByAppendingString:(NSAttributedString *)append {
  NSMutableAttributedString *result = [self mutableCopy];
  [result appendAttributedString:append];
  NSAttributedString *copy = [result copy];
  return copy;
}

Answer 8

您可以尝试SwiftyFormat 它使用以下语法

let format = "#{{user}} mentioned you in a comment. #{{comment}}"
let message = NSAttributedString(format: format,
                                 attributes: commonAttributes,
                                 mapping: ["user": attributedName, "comment": attributedComment])