NSAttributedString 可以非常方便的实现文字排版和图文混排功能. 共有21种效果(API), 本文将较详细的介绍21种属性的使用
核心API: NSAttributedString. NSMutableAttributedString.
NSString *string = @"An NSAttributedString object manages character strings and associated sets of attributes (for example, font and kerning) that apply to individual characters or ranges of characters in the string. An association of characters and their attributes is called an attributed string. ";
/* 这句话就是对这个类的一个最简明扼要的概括。NSAttributedString管理一个字符串,以及与该字符串中的单个字符或某些范围的字符串相关的属性。它有一个子类NSMutableAttributedString
* 具体实现时,NSAttributedString维护了一个NSString,用来保存最原始的字符串,另有一个NSDictionary用来保存各个子串/字符的属性。
*/
#pragma mark - NSMutableAttributedString 创建
/* 三种初始化方法,NSMutableAttributedString没有初始化方法,使用父类初始化方法, 使用initWithString:, initWithString:attributes:, 或者 initWithAttributedString: */
NSAttributedString *attStr = [[NSAttributedString alloc] initWithString:string attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:30]}];
NSMutableAttributedString *mAttStr = [[NSMutableAttributedString alloc] initWithString:string];
1.NSFontAttributeName ->设置字体属性,默认值:字体:Helvetica(Neue) 字号:12
/* 设置字体大小及字体类型 */
NSRange font_range = [string rangeOfString:@"An"];
[mAttStr addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:20] range:font_range];
[mAttStr addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Courier-BoldOblique" size:17.0] range:NSMakeRange(10, 10)];
2.NSParagraphStyleAttributeName ->设置文本段落排版格式,取值为 NSParagraphStyle 对象(详情见如下代码)
-
NSParagraphStyle与NSMutableParagraphStyle包括以下属性
- alignment ->对齐方式
- firstLineHeadIndent ->首行缩进
- headIndent ->缩进
- tailIndent ->尾部缩进
- lineBreakMode ->断行方式
- maximumLineHeight ->最大行高
- minimumLineHeight ->最低行高
- lineSpacing ->行距
- paragraphSpacing ->段距
- paragraphSpacingBefore ->段首空间
- baseWritingDirection ->句子方向
- lineHeightMultiple ->可变行高,乘因数。
- hyphenationFactor ->连字符属性
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
style.firstLineHeadIndent = 10;
style.lineSpacing = 10;
[mAttStr addAttribute:NSParagraphStyleAttributeName value:style range:NSMakeRange(10, 10)];
3.NSForegroundColorAttributeName ->设置字体颜色,取值为 UIColor对象,默认值为黑色
[mAttStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(10, 10)];
4.NSBackgroundColorAttributeName ->设置字体所在区域背景颜色,取值为 UIColor对象,默认值为nil, 透明色
[mAttStr addAttribute:NSBackgroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(10, 10)];
5.NSLigatureAttributeName ->设置连体属性,取值为NSNumber 对象(整数),0 表示没有连体字符,1 表示使用默认的连体字符
[mAttStr addAttribute:NSLigatureAttributeName value:@1 range:NSMakeRange(10, 10)];
6.NSKernAttributeName ->设置字符间距,取值为 NSNumber 对象(整数),正值间距加宽,负值间距变窄
[mAttStr addAttribute:NSKernAttributeName value:@2 range:NSMakeRange(10, 10)];
7.NSStrikethroughStyleAttributeName ->设置删除线,取值为 NSNumber 对象(整数)
/* 值为整型NSNumber,可取值为 NSUnderlineStyle
enum {
NSUnderlineStyleNone = 0x00,
NSUnderlineStyleSingle = 0x01,
NSUnderlineStyleThick NS_ENUM_AVAILABLE(10_0, 7_0) = 0x02,
NSUnderlineStyleDouble NS_ENUM_AVAILABLE(10_0, 7_0) = 0x09,
NSUnderlinePatternSolid NS_ENUM_AVAILABLE(10_0, 7_0) = 0x0000,
NSUnderlinePatternDot NS_ENUM_AVAILABLE(10_0, 7_0) = 0x0100,
NSUnderlinePatternDash NS_ENUM_AVAILABLE(10_0, 7_0) = 0x0200,
NSUnderlinePatternDashDot NS_ENUM_AVAILABLE(10_0, 7_0) = 0x0300,
NSUnderlinePatternDashDotDot NS_ENUM_AVAILABLE(10_0, 7_0) = 0x0400,
NSUnderlineByWord NS_ENUM_AVAILABLE(10_0, 7_0) = 0x8000
}; 设置删除线。
*/
[mAttStr addAttribute:NSStrikethroughStyleAttributeName value:@3 range:NSMakeRange(10, 10)];
8.NSStrikethroughColorAttributeName ->设置删除线颜色,取值为 UIColor 对象,默认值为黑色
[mAttStr addAttribute:NSStrikethroughColorAttributeName value:[UIColor blueColor] range:NSMakeRange(10, 10)];
9.NSUnderlineStyleAttributeName ->设置下划线,取值为 NSNumber 对象(整数),枚举常量 NSUnderlineStyle中的值,与删除线类似
[mAttStr addAttribute:NSUnderlineStyleAttributeName value:@3 range:NSMakeRange(10, 10)];
10.NSUnderlineColorAttributeName ->设置下划线颜色,取值为 UIColor 对象,默认值为nil
[mAttStr addAttribute:NSUnderlineColorAttributeName value:[UIColor blackColor] range:NSMakeRange(10, 10)];
11.NSStrokeWidthAttributeName ->设置笔画宽度(粗细),取值为 NSNumber 对象(整数),负值填充效果,正值中空效果
[mAttStr addAttribute:NSStrokeWidthAttributeName value:@10 range:NSMakeRange(10, 10)];
12.NSStrokeColorAttributeName ->填充部分颜色,不是字体颜色,取值为 UIColor 对象 默认值为nil,设置的属性同ForegroundColor
[mAttStr addAttribute:NSStrokeColorAttributeName value:[UIColor radColor] range:NSMakeRange(10, 10)];
13.NSShadowAttributeName ->设置阴影属性,取值为 NSShadow 对象 默认值为nil
NSShadow *shadow = [[NSShadow alloc]init];
shadow.shadowOffset = CGSizeMake(10, 10);
shadow.shadowColor = [UIColor redColor];
[mAttStr addAttribute:NSShadowAttributeName value:shadow range:NSMakeRange(10, 10)];
14.NSTextEffectAttributeName ->设置文本特殊效果,取值为 NSString 对象,目前只有图版印刷效果可用, 使用此属性指定的文字效果,如NSTextEffectLetterpressStyle。此属性的默认值为nil,表示没有文本效应
[mAttStr addAttribute:NSTextEffectAttributeName value:NSTextEffectLetterpressStyle range:NSMakeRange(10, 10)];
15.NSBaselineOffsetAttributeName ->设置基线偏移值,取值为 NSNumber (float),正值上偏,负值下偏, 默认值是0
[mAttStr addAttribute:NSBaselineOffsetAttributeName value:@1 range:NSMakeRange(10, 10)];
16.NSObliquenessAttributeName ->设置字形倾斜度,取值为 NSNumber (float),正值右倾,负值左倾, 默认值是0(表示没有倾斜)
[mAttStr addAttribute:NSObliquenessAttributeName value:@0.5 range:NSMakeRange(10, 10)];
17.NSExpansionAttributeName ->设置文本横向拉伸属性,取值为 NSNumber (float),正值横向拉伸文本,负值横向压缩文本
[mAttStr addAttribute:NSExpansionAttributeName value:@1.0 range:NSMakeRange(10, 10)];
18.NSWritingDirectionAttributeName ->设置文字书写方向,从左向右书写或者从右向左书写
//取值为包含NSNumber对象的数组. 从左向右书写或者从右向左书写.
// NSArray of NSNumbers representing the nested levels of writing direction overrides as
defined by Unicode LRE, RLE, LRO, and RLO characters. The control characters can be
obtained by masking NSWritingDirection and NSTextWritingDirection values. LRE:
NSWritingDirectionLeftToRight|NSWritingDirectionEmbedding, RLE:
NSWritingDirectionRightToLeft|NSWritingDirectionEmbedding, LRO:
NSWritingDirectionLeftToRight|NSWritingDirectionOverride, RLO:
NSWritingDirectionRightToLeft|NSWritingDirectionOverride,
[mAttStr addAttribute:NSWritingDirectionAttributeName value:@[@2] range:NSMakeRange(10, 10)];
19.NSVerticalGlyphFormAttributeName ->设置文字排版方向,取值为 NSNumber 对象(整数),0 表示横排文本,1 表示竖排文本 在iOS中, 总是以横向排版
[mAttStr addAttribute:NSVerticalGlyphFormAttributeName value:@0 range:NSMakeRange(10, 10)];
20.NSLinkAttributeName ->设置链接属性,点击后调用浏览器打开指定URL地址
/**
* 此属性的值是NSURL对象(首选)或一个NSString对象。此属性的默认值为nil,表示没有链接。
* UILabel无法使用该属性, 可以使用UITextView 控件.
*/
UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(50, 50, 50, 50)];
[self.view addSubview:textView];
textView.backgroundColor = [UIColor redColor];
NSString *strLink = @"百度链接";
NSAttributedString *attStrUrl = [[NSAttributedString alloc] initWithString:strLink attributes:@{NSLinkAttributeName: [NSURL URLWithString:@"http://www.baidu.com"]}];
textView.editable = NO;
/* 签订协议, 指定代理人之后. 但点击链接时, 会回调协议方法 (- textView:shouldInteractWithURL:inRange:) */
textView.delegate = self;
textView.attributedText = attStr;
- (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRange:(NSRange)characterRange {
NSLog(@"%s", __FUNCTION__);
NSLog(@"url: %@", URL);
return YES;
}
注意:
@interface ViewController () <UITextViewDelegate>
21.NSAttachmentAttributeName ->设置文本附件,取值为NSTextAttachment对象,常用于文字图片混排
/* 这个属性的值是一个NSTextAttachment对象。此属性的默认值为nil,表示无附件。*/
/**
* 关于NSTextAttachment类的简单说明
*
* NSTextAttachment 类有一个指定的初始化方法(- initWithData:ofType:), 需要指定附件文档的数据和附件文件的类型. 如果附件文档数据指定nil, 那么系统将会默认指定为image对象作为值. 因此, 也可以通过这个特性实现图文混排.
* 下面就以附件为image对象来说明NSAttachmentAttributeName的使用.
*
*/
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 50, 50, 50)];
label.backgroundColor = [UIColor redColor];
[self.view addSubview:label];
/* 下面实现在百度两个汉字之间插入一个照片 */
NSString *stiAtt = @"百度";
NSTextAttachment *attach = [[NSTextAttachment alloc] initWithData:nil ofType:nil];
attach.bounds = CGRectMake(0, 0, 50, 50);
attach.image = [UIImage imageNamed:@"taobao.jpg"];
NSAttributedString *strAtt = [NSAttributedString attributedStringWithAttachment:attach];
NSMutableAttributedString *strMatt = [[NSMutableAttributedString alloc] initWithString:stiAtt];
[strMatt insertAttributedString:strAtt atIndex:1];
label.attributedText = strMatt;
self.titleLabel.attributedText = mAttStr;
[self.titleLabel sizeToFit];
在此要感谢我的启蒙老师, 原哥, 是他带我走上了iOS编程这条"不归"之路!
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