在NSString或nsmutablestring中不可能有多种颜色。我听说过一点NSAttributedString，它是在iPad SDK 3.2(或大约3.2)中引入的，并且在iPhone SDK 4.0 beta版中可用。
我想要一根有三种颜色的绳子。
我不使用3个独立的NSString的原因，是因为三个NSAttributedString子字符串的长度经常改变，所以我宁愿，不使用任何计算重新定位3个独立的NSString对象。
如果使用NSAttributedString是可能的，我怎么做以下-(如果不可能使用NSAttributedString，你会怎么做):
编辑: 记住，@"first"， @"second"和@"third"随时会被其他字符串替换。所以使用硬编码的NSRange值是行不通的。
当前回答
在Swift 4中:
let string:NSMutableAttributedString = {
let mutableString = NSMutableAttributedString(string: "firstsecondthird")
mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.red , range: NSRange(location: 0, length: 5))
mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.green , range: NSRange(location: 5, length: 6))
mutableString.addAttribute(NSForegroundColorAttributeName, value: UIColor.blue , range: NSRange(location: 11, length: 5))
return mutableString
}()
print(string)
其他回答
为了解决这类问题，我在swift中创建了一个名为Atributika的库。
let str = "<r>first</r><g>second</g><b>third</b>".style(tags:
Style("r").foregroundColor(.red),
Style("g").foregroundColor(.green),
Style("b").foregroundColor(.blue)).attributedString
label.attributedText = str
你可以在这里找到它https://github.com/psharanda/Atributika
你可以加载一个HTML带属性的字符串在Swift如下
var Str = NSAttributedString(
data: htmlstring.dataUsingEncoding(NSUnicodeStringEncoding, allowLossyConversion: true),
options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
documentAttributes: nil,
error: nil)
label.attributedText = Str
从文件中加载html
if let rtf = NSBundle.mainBundle().URLForResource("rtfdoc", withExtension: "rtf", subdirectory: nil, localization: nil) {
let attributedString = NSAttributedString(fileURL: rtf, options: [NSDocumentTypeDocumentAttribute:NSRTFTextDocumentType], documentAttributes: nil, error: nil)
textView.attributedText = attributedString
textView.editable = false
}
http://sketchytech.blogspot.in/2013/11/creating-nsattributedstring-from-html.html
和设置字符串根据您所需的属性....遵循这个. . http://makeapppie.com/2014/10/20/swift-swift-using-attributed-strings-in-swift/
带属性字符串扩展的更简单的解决方案。
extension NSMutableAttributedString {
// this function attaches color to string
func setColorForText(textToFind: String, withColor color: UIColor) {
let range: NSRange = self.mutableString.range(of: textToFind, options: .caseInsensitive)
self.addAttribute(NSAttributedStringKey.foregroundColor, value: color, range: range)
}
}
试试这个，看看(在Swift 3和4中测试)
let label = UILabel()
label.frame = CGRect(x: 120, y: 100, width: 200, height: 30)
let first = "first"
let second = "second"
let third = "third"
let stringValue = "\(first)\(second)\(third)" // or direct assign single string value like "firstsecondthird"
let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: stringValue)
attributedString.setColorForText(textToFind: first, withColor: UIColor.red) // use variable for string "first"
attributedString.setColorForText(textToFind: "second", withColor: UIColor.green) // or direct string like this "second"
attributedString.setColorForText(textToFind: third, withColor: UIColor.blue)
label.font = UIFont.systemFont(ofSize: 26)
label.attributedText = attributedString
self.view.addSubview(label)
以下是预期结果:
在构建带属性字符串时，我更喜欢使用可变子类，只是为了让事情更简洁。
话虽如此，下面是如何创建一个三色带属性字符串:
NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"firstsecondthird"];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,5)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(5,6)];
[string addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:NSMakeRange(11,5)];
在浏览器中输入。警告实现者
显然你不会像这样硬编码。也许你可以这样做:
NSDictionary *wordToColorMapping = ....; //an NSDictionary of NSString => UIColor pairs
NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@""];
for (NSString *word in wordToColorMapping) {
UIColor *color = [wordToColorMapping objectForKey:word];
NSDictionary *attributes = [NSDictionary dictionaryWithObject:color forKey:NSForegroundColorAttributeName];
NSAttributedString *subString = [[NSAttributedString alloc] initWithString:word attributes:attributes];
[string appendAttributedString:subString];
[subString release];
}
//display string
我总是发现使用带属性的字符串是一个令人难以置信的漫长而乏味的过程。
所以我做了一个Mac应用程序，为你创建所有的代码。
https://itunes.apple.com/us/app/attributed-string-creator/id730928349?mt=12
