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
其他回答
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
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'
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;
- (void)changeColorWithString:(UILabel *)uilabel stringToReplace:(NSString *) stringToReplace uiColor:(UIColor *) uiColor{
NSMutableAttributedString *text =
[[NSMutableAttributedString alloc]
initWithAttributedString: uilabel.attributedText];
[text addAttribute: NSForegroundColorAttributeName value:uiColor range:[uilabel.text rangeOfString:stringToReplace]];
[uilabel setAttributedText: text];
}
