如何连接NSAttributedStrings？

我需要搜索一些字符串并在合并字符串之前设置一些属性，因此让NSStrings->串联它们->使NSAttributedString不是一个选择，有没有办法将attributedString串联到另一个attributedString？

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，仅出于获得所有选项的目的，您还可以创建一个可变的属性字符串，该字符串由包含已放在一起的输入字符串的格式化NSString组成。然后，您可以addAttributes: range:用于将事实之后的属性添加到包含输入字符串的范围中。我推荐前一种方式。

如果您使用的是Swift，则可以重载+运算符，以便以与连接普通字符串相同的方式来连接它们：

// 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串联它们：

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

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

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 upd：

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

试试这个：

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

哪里astring1和astring2在哪里NSAttributedString。

2020 | SWIFT 5.1：

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

let concatenated = NSAttrStr1.append(NSAttrStr2)

NSMutableAttributedString和NSAttributedString两者都可以使用的另一种方式：

[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
    }
}

如果您使用的是Cocoapods，则上述两个答案的替代方法（可避免在自己的代码中发生变异）是在NSAttributedStrings 上使用出色的NSAttributedString + CCLFormat类别，该类别可让您编写以下内容：

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

当然，它只是NSMutableAttributedString在幕后使用。

它还有一个完全成熟的格式化功能的额外优点-因此它比将字符串附加在一起还可以做更多的事情。

// 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;
}

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])