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
这个解对任何长度都适用
NSString *strFirst = @"Anylengthtext";
NSString *strSecond = @"Anylengthtext";
NSString *strThird = @"Anylengthtext";
NSString *strComplete = [NSString stringWithFormat:@"%@ %@ %@",strFirst,strSecond,strThird];
NSMutableAttributedString *attributedString =[[NSMutableAttributedString alloc] initWithString:strComplete];
[attributedString addAttribute:NSForegroundColorAttributeName
value:[UIColor redColor]
range:[strComplete rangeOfString:strFirst]];
[attributedString addAttribute:NSForegroundColorAttributeName
value:[UIColor yellowColor]
range:[strComplete rangeOfString:strSecond]];
[attributedString addAttribute:NSForegroundColorAttributeName
value:[UIColor blueColor]
range:[strComplete rangeOfString:strThird]];
self.lblName.attributedText = attributedString;
其他回答
自iOS 7以来，你可以使用NSAttributedString与HTML语法:
NSURL *htmlString = [[NSBundle mainBundle] URLForResource: @"string" withExtension:@"html"];
NSAttributedString *stringWithHTMLAttributes = [[NSAttributedString alloc] initWithFileURL:htmlString
options:@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType}
documentAttributes:nil
error:nil];
textView.attributedText = stringWithHTMLAttributes;// you can use a label also
你必须添加文件"string.html"到你的项目中，html的内容可以是这样的:
<html>
<head>
<style type="text/css">
body {
font-size: 15px;
font-family: Avenir, Arial, sans-serif;
}
.red {
color: red;
}
.green {
color: green;
}
.blue {
color: blue;
}
</style>
</head>
<body>
<span class="red">first</span><span class="green">second</span><span class="blue">third</span>
</body>
</html>
现在，你可以使用NSAttributedString作为你想要的，即使没有HTML文件，例如:
//At the top of your .m file
#define RED_OCCURENCE -red_occurence-
#define GREEN_OCCURENCE -green_occurence-
#define BLUE_OCCURENCE -blue_occurence-
#define HTML_TEMPLATE @"<span style=\"color:red\">-red_occurence-</span><span style=\"color:green\">-green_occurence-</span><span style=\"color:blue\">-blue_occurence-</span></body></html>"
//Where you need to use your attributed string
NSString *string = [HTML_TEMPLATE stringByReplacingOccurrencesOfString:RED_OCCURENCE withString:@"first"] ;
string = [string stringByReplacingOccurrencesOfString:GREEN_OCCURENCE withString:@"second"];
string = [string stringByReplacingOccurrencesOfString:BLUE_OCCURENCE withString:@"third"];
NSData* cData = [string dataUsingEncoding:NSUTF8StringEncoding];
NSAttributedString *stringWithHTMLAttributes = [[NSAttributedString alloc] initWithData:cData
options:@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType}
documentAttributes:nil
error:nil];
textView.attributedText = stringWithHTMLAttributes;
源
我写了helper来方便地添加属性:
- (void)addColor:(UIColor *)color substring:(NSString *)substring;
- (void)addBackgroundColor:(UIColor *)color substring:(NSString *)substring;
- (void)addUnderlineForSubstring:(NSString *)substring;
- (void)addStrikeThrough:(int)thickness substring:(NSString *)substring;
- (void)addShadowColor:(UIColor *)color width:(int)width height:(int)height radius:(int)radius substring:(NSString *)substring;
- (void)addFontWithName:(NSString *)fontName size:(int)fontSize substring:(NSString *)substring;
- (void)addAlignment:(NSTextAlignment)alignment substring:(NSString *)substring;
- (void)addColorToRussianText:(UIColor *)color;
- (void)addStrokeColor:(UIColor *)color thickness:(int)thickness substring:(NSString *)substring;
- (void)addVerticalGlyph:(BOOL)glyph substring:(NSString *)substring;
https://github.com/shmidt/MASAttributes
你也可以通过CocoaPods安装:pod 'MASAttributes'， '~> 1.0.0'
我认为，使用正则表达式来查找应用属性的范围是一种非常方便的方法。我是这样做的:
NSMutableAttributedString *goodText = [[NSMutableAttributedString alloc] initWithString:articleText];
NSRange range = [articleText rangeOfString:@"\\[.+?\\]" options:NSRegularExpressionSearch|NSCaseInsensitiveSearch];
if (range.location != NSNotFound) {
[goodText addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Georgia" size:16] range:range];
[goodText addAttribute:NSForegroundColorAttributeName value:[UIColor brownColor] range:range];
}
NSString *regEx = [NSString stringWithFormat:@"%@.+?\\s", [self.article.titleText substringToIndex:0]];
range = [articleText rangeOfString:regEx options:NSRegularExpressionSearch|NSCaseInsensitiveSearch];
if (range.location != NSNotFound) {
[goodText addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Georgia-Bold" size:20] range:range];
[goodText addAttribute:NSForegroundColorAttributeName value:[UIColor blueColor] range:range];
}
[self.textView setAttributedText:goodText];
我正在搜索可用属性的列表，但在这里和类引用的第一页中都没有找到它们。所以我决定在这里发布相关信息。
标准属性
带属性字符串支持以下文本的标准属性。如果键不在字典中，则使用下面描述的默认值。
NSString *NSFontAttributeName;
NSString *NSParagraphStyleAttributeName;
NSString *NSForegroundColorAttributeName;
NSString *NSUnderlineStyleAttributeName;
NSString *NSSuperscriptAttributeName;
NSString *NSBackgroundColorAttributeName;
NSString *NSAttachmentAttributeName;
NSString *NSLigatureAttributeName;
NSString *NSBaselineOffsetAttributeName;
NSString *NSKernAttributeName;
NSString *NSLinkAttributeName;
NSString *NSStrokeWidthAttributeName;
NSString *NSStrokeColorAttributeName;
NSString *NSUnderlineColorAttributeName;
NSString *NSStrikethroughStyleAttributeName;
NSString *NSStrikethroughColorAttributeName;
NSString *NSShadowAttributeName;
NSString *NSObliquenessAttributeName;
NSString *NSExpansionAttributeName;
NSString *NSCursorAttributeName;
NSString *NSToolTipAttributeName;
NSString *NSMarkedClauseSegmentAttributeName;
NSString *NSWritingDirectionAttributeName;
NSString *NSVerticalGlyphFormAttributeName;
NSString *NSTextAlternativesAttributeName;
NSAttributedString编程指南
完整的类参考在这里。
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)
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
