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
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:
其他回答
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
- (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];
}
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。
问题已经有了答案……但是我想展示如何用NSAttributedString添加阴影和改变字体，这样当人们搜索这个主题时，他们就不用一直找了。
#define FONT_SIZE 20
#define FONT_HELVETICA @"Helvetica-Light"
#define BLACK_SHADOW [UIColor colorWithRed:40.0f/255.0f green:40.0f/255.0f blue:40.0f/255.0f alpha:0.4f]
NSString*myNSString = @"This is my string.\nIt goes to a second line.";
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.alignment = NSTextAlignmentCenter;
paragraphStyle.lineSpacing = FONT_SIZE/2;
UIFont * labelFont = [UIFont fontWithName:FONT_HELVETICA size:FONT_SIZE];
UIColor * labelColor = [UIColor colorWithWhite:1 alpha:1];
NSShadow *shadow = [[NSShadow alloc] init];
[shadow setShadowColor : BLACK_SHADOW];
[shadow setShadowOffset : CGSizeMake (1.0, 1.0)];
[shadow setShadowBlurRadius : 1];
NSAttributedString *labelText = [[NSAttributedString alloc] initWithString : myNSString
attributes : @{
NSParagraphStyleAttributeName : paragraphStyle,
NSKernAttributeName : @2.0,
NSFontAttributeName : labelFont,
NSForegroundColorAttributeName : labelColor,
NSShadowAttributeName : shadow }];
这是一个Swift版本…
警告! 这适用于4s。
5s你必须改变所有的Float值为Double值(因为编译器还没有正确工作)
字体选择的Swift枚举:
enum FontValue: Int {
case FVBold = 1 , FVCondensedBlack, FVMedium, FVHelveticaNeue, FVLight, FVCondensedBold, FVLightItalic, FVUltraLightItalic, FVUltraLight, FVBoldItalic, FVItalic
}
用于enum访问的Swift数组(因为enum不能使用'-'):
func helveticaFont (index:Int) -> (String) {
let fontArray = [
"HelveticaNeue-Bold",
"HelveticaNeue-CondensedBlack",
"HelveticaNeue-Medium",
"HelveticaNeue",
"HelveticaNeue-Light",
"HelveticaNeue-CondensedBold",
"HelveticaNeue-LightItalic",
"HelveticaNeue-UltraLightItalic",
"HelveticaNeue-UltraLight",
"HelveticaNeue-BoldItalic",
"HelveticaNeue-Italic",
]
return fontArray[index]
}
Swift属性文本函数:
func myAttributedText (myString:String, mySize: Float, myFont:FontValue) -> (NSMutableAttributedString) {
let shadow = NSShadow()
shadow.shadowColor = UIColor.textShadowColor()
shadow.shadowOffset = CGSizeMake (1.0, 1.0)
shadow.shadowBlurRadius = 1
let paragraphStyle = NSMutableParagraphStyle.alloc()
paragraphStyle.lineHeightMultiple = 1
paragraphStyle.lineBreakMode = NSLineBreakMode.ByWordWrapping
paragraphStyle.alignment = NSTextAlignment.Center
let labelFont = UIFont(name: helveticaFont(myFont.toRaw()), size: mySize)
let labelColor = UIColor.whiteColor()
let myAttributes :Dictionary = [NSParagraphStyleAttributeName : paragraphStyle,
NSKernAttributeName : 3, // (-1,5)
NSFontAttributeName : labelFont,
NSForegroundColorAttributeName : labelColor,
NSShadowAttributeName : shadow]
let myAttributedString = NSMutableAttributedString (string: myString, attributes:myAttributes)
// add new color
let secondColor = UIColor.blackColor()
let stringArray = myString.componentsSeparatedByString(" ")
let firstString: String? = stringArray.first
let letterCount = countElements(firstString!)
if firstString {
myAttributedString.addAttributes([NSForegroundColorAttributeName:secondColor], range:NSMakeRange(0,letterCount))
}
return myAttributedString
}
第一个和最后一个扩展名用于查找字符串数组中的范围:
extension Array {
var last: T? {
if self.isEmpty {
NSLog("array crash error - please fix")
return self [0]
} else {
return self[self.endIndex - 1]
}
}
}
extension Array {
var first: T? {
if self.isEmpty {
NSLog("array crash error - please fix")
return self [0]
} else {
return self [0]
}
}
}
新的颜色:
extension UIColor {
class func shadowColor() -> UIColor {
return UIColor(red: 0.0/255.0, green: 0.0/255.0, blue: 0.0/255.0, alpha: 0.3)
}
class func textShadowColor() -> UIColor {
return UIColor(red: 50.0/255.0, green: 50.0/255.0, blue: 50.0/255.0, alpha: 0.5)
}
class func pastelBlueColor() -> UIColor {
return UIColor(red: 176.0/255.0, green: 186.0/255.0, blue: 255.0/255.0, alpha: 1)
}
class func pastelYellowColor() -> UIColor {
return UIColor(red: 255.0/255.0, green: 238.0/255.0, blue: 140.0/255.0, alpha: 1)
}
}
我的宏替换:
enum MyConstants: Float {
case CornerRadius = 5.0
}
我的按钮制造商w/带属性的文本:
func myButtonMaker (myView:UIView) -> UIButton {
let myButton = UIButton.buttonWithType(.System) as UIButton
myButton.backgroundColor = UIColor.pastelBlueColor()
myButton.showsTouchWhenHighlighted = true;
let myCGSize:CGSize = CGSizeMake(100.0, 50.0)
let myFrame = CGRectMake(myView.frame.midX - myCGSize.height,myView.frame.midY - 2 * myCGSize.height,myCGSize.width,myCGSize.height)
myButton.frame = myFrame
let myTitle = myAttributedText("Button",20.0,FontValue.FVLight)
myButton.setAttributedTitle(myTitle, forState:.Normal)
myButton.layer.cornerRadius = myButton.bounds.size.width / MyConstants.CornerRadius.toRaw()
myButton.setTitleColor(UIColor.whiteColor(), forState: .Normal)
myButton.tag = 100
myButton.bringSubviewToFront(myView)
myButton.layerGradient()
myView.addSubview(myButton)
return myButton
}
我的UIView/UILabel maker w/带属性的文本，阴影和圆角:
func myLabelMaker (myView:UIView) -> UIView {
let myFrame = CGRectMake(myView.frame.midX / 2 , myView.frame.midY / 2, myView.frame.width/2, myView.frame.height/2)
let mylabelFrame = CGRectMake(0, 0, myView.frame.width/2, myView.frame.height/2)
let myBaseView = UIView()
myBaseView.frame = myFrame
myBaseView.backgroundColor = UIColor.clearColor()
let myLabel = UILabel()
myLabel.backgroundColor=UIColor.pastelYellowColor()
myLabel.frame = mylabelFrame
myLabel.attributedText = myAttributedText("This is my String",20.0,FontValue.FVLight)
myLabel.numberOfLines = 5
myLabel.tag = 100
myLabel.layer.cornerRadius = myLabel.bounds.size.width / MyConstants.CornerRadius.toRaw()
myLabel.clipsToBounds = true
myLabel.layerborders()
myBaseView.addSubview(myLabel)
myBaseView.layerShadow()
myBaseView.layerGradient()
myView.addSubview(myBaseView)
return myLabel
}
通用阴影添加:
func viewshadow<T where T: UIView> (shadowObject: T)
{
let layer = shadowObject.layer
let radius = shadowObject.frame.size.width / MyConstants.CornerRadius.toRaw();
layer.borderColor = UIColor.whiteColor().CGColor
layer.borderWidth = 0.8
layer.cornerRadius = radius
layer.shadowOpacity = 1
layer.shadowRadius = 3
layer.shadowOffset = CGSizeMake(2.0,2.0)
layer.shadowColor = UIColor.shadowColor().CGColor
}
视图样式的视图扩展:
extension UIView {
func layerborders() {
let layer = self.layer
let frame = self.frame
let myColor = self.backgroundColor
layer.borderColor = myColor.CGColor
layer.borderWidth = 10.8
layer.cornerRadius = layer.borderWidth / MyConstants.CornerRadius.toRaw()
}
func layerShadow() {
let layer = self.layer
let frame = self.frame
layer.cornerRadius = layer.borderWidth / MyConstants.CornerRadius.toRaw()
layer.shadowOpacity = 1
layer.shadowRadius = 3
layer.shadowOffset = CGSizeMake(2.0,2.0)
layer.shadowColor = UIColor.shadowColor().CGColor
}
func layerGradient() {
let layer = CAGradientLayer()
let size = self.frame.size
layer.frame.size = size
layer.frame.origin = CGPointMake(0.0,0.0)
layer.cornerRadius = layer.bounds.size.width / MyConstants.CornerRadius.toRaw();
var color0 = CGColorCreateGenericRGB(250.0/255, 250.0/255, 250.0/255, 0.5)
var color1 = CGColorCreateGenericRGB(200.0/255, 200.0/255, 200.0/255, 0.1)
var color2 = CGColorCreateGenericRGB(150.0/255, 150.0/255, 150.0/255, 0.1)
var color3 = CGColorCreateGenericRGB(100.0/255, 100.0/255, 100.0/255, 0.1)
var color4 = CGColorCreateGenericRGB(50.0/255, 50.0/255, 50.0/255, 0.1)
var color5 = CGColorCreateGenericRGB(0.0/255, 0.0/255, 0.0/255, 0.1)
var color6 = CGColorCreateGenericRGB(150.0/255, 150.0/255, 150.0/255, 0.1)
layer.colors = [color0,color1,color2,color3,color4,color5,color6]
self.layer.insertSublayer(layer, atIndex: 2)
}
}
实际视图didload函数:
func buttonPress (sender:UIButton!) {
NSLog("%@", "ButtonPressed")
}
override func viewDidLoad() {
super.viewDidLoad()
let myLabel = myLabelMaker(myView)
let myButton = myButtonMaker(myView)
myButton.addTarget(self, action: "buttonPress:", forControlEvents:UIControlEvents.TouchUpInside)
viewshadow(myButton)
viewshadow(myLabel)
}
