iOS6之后 NSAttributedString 的福利

@在iOS6之前需要使用NSMutableAttributedString时都需要导入：CoreText.framework框架的，但在iOS6 之后就不在需要了.

 - (void)testOfNSMutableAttributedStringAndNSAttributedString
 {
     /**
      *  - (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range;
      *  主要方法
      *  name   属性名
      *  value  属性对应效果的值
      *  range  效果所映射的范围
      */

     #pragma mark  测试数据0
     NSString *testString = @"NSMutableAttributed---0";
     UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(60, 100, 200, 40)];
     NSMutableAttributedString * testAttriString = [[NSMutableAttributedString alloc] initWithString:testString];
     // 添加删除线
     [testAttriString addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleSingle] range:NSMakeRange(0, testAttriString.length)];
     // 添加下划线
     [testAttriString addAttribute:NSUnderlineStyleAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleSingle] range:NSMakeRange(0, testAttriString.length)];
     // 设置文本的字体以及大小
     [testAttriString addAttribute:NSFontAttributeName value:[UIFont fontWithName:@"Helvetica-Bold" size:15] range:NSMakeRange(0, testAttriString.length)];
     // 设置笔画的粗细
     [testAttriString addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleDouble] range:NSMakeRange(0, testAttriString.length)];
     // label的背景颜色
     [testAttriString addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:NSMakeRange(0, testAttriString.length)];
     // 目前没测出什么效果.....
     [testAttriString addAttribute:NSVerticalGlyphFormAttributeName value:[NSNumber numberWithInt:1] range:NSMakeRange(0, testAttriString.length)];
     // label上文本颜色(也会影响删除线和下划线的颜色)
     [testAttriString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, testAttriString.length)];
     testLabel.attributedText = testAttriString;

     #pragma mark 测试数据1
     NSString *testString1 = @"NSMutableAttributed---1";
     UILabel *testLabel1 = [[UILabel alloc] initWithFrame:CGRectMake(60, 200, 200, 40)];
     NSMutableAttributedString * testAttriString1 = [[NSMutableAttributedString alloc] initWithString:testString1];
     // 实现文本内容颜色和下划线,删除线的颜色不一样
     // NSStrokeColorAttributeName 单独设置没有效果
     // 必须与NSStrokeWidthAttributeName一起设置
     [testAttriString1 addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleSingle] range:NSMakeRange(0, testAttriString1.length)];
     [testAttriString1 addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, testAttriString1.length)];
     [testAttriString1 addAttribute:NSStrokeColorAttributeName value:[UIColor cyanColor] range:NSMakeRange(0, testAttriString1.length)];
     [testAttriString1 addAttribute:NSStrokeWidthAttributeName value:[NSNumber numberWithInt:NSUnderlineStyleDouble] range:NSMakeRange(0, testAttriString1.length)];
     testLabel1.attributedText = testAttriString1;


     #pragma mark 测试数据2
     NSString *testString2 = @"NSMutableAttributed---2";
     UILabel *testLabel2= [[UILabel alloc] initWithFrame:CGRectMake(60, 300, 200, 40)];
     NSMutableAttributedString * testAttriString2 = [[NSMutableAttributedString alloc] initWithString:testString2];
     // 笔画的阴影效果
     NSShadow *shadow = [[NSShadow alloc] init];
     [shadow setShadowColor:[UIColor colorWithRed:0.053 green:0.088 blue:0.205 alpha:1.000]];
     [shadow setShadowBlurRadius:4.0];
     [shadow setShadowOffset:CGSizeMake(2, 2)];
     [testAttriString2 addAttribute:NSShadowAttributeName value:shadow range:NSMakeRange(0, [testAttriString2 length])];
     testLabel2.backgroundColor = [UIColor clearColor];
     testLabel2.attributedText = testAttriString2;

     [self.view addSubview:testLabel];
     [self.view addSubview:testLabel1];
     [self.view addSubview:testLabel2];
 }

 使用AttributedString的方式通常有两种：

 方式一：

     首先初始化一个NSMutableAttributedString，然后向里面添加文字样式，最后将它赋给控件的AttributedText，该方法适合于文本较少而又需要分段精细控制的情况。


 NSString *originStr = @"Hello,中秋节！";

 //方式一

 //创建 NSMutableAttributedString
 NSMutableAttributedString *attributedStr01 = [[NSMutableAttributedString alloc] initWithString: originStr];

 //添加属性

 //给所有字符设置字体为Zapfino，字体高度为15像素
 [attributedStr01 addAttribute: NSFontAttributeName value: [UIFont fontWithName: @"Zapfino" size: 15]
                                                    range: NSMakeRange(0, originStr.length)];
 //分段控制，最开始4个字符颜色设置成蓝色
 [attributedStr01 addAttribute: NSForegroundColorAttributeName value: [UIColor blueColor] range: NSMakeRange(0, 4)];
 //分段控制，第5个字符开始的3个字符，即第5、6、7字符设置为红色
 [attributedStr01 addAttribute: NSForegroundColorAttributeName value: [UIColor redColor] range: NSMakeRange(4, 3)];

 //赋值给显示控件label01的 attributedText
 _label01.attributedText = attributedStr01;




 方式二：

       首先创建属性字典，初始化各种属性，然后和需要控制的文本一起创建并赋值给控件的AttributedText，该方法适合于需要控制的文本较多整体控制的情况，通常是从文件中读取的大段文本控制。


 //方式二

 //创建属性字典
 NSDictionary *attrDict = @{ NSFontAttributeName: [UIFont fontWithName: @"Zapfino" size: 15],
                             NSForegroundColorAttributeName: [UIColor blueColor] };

 //创建 NSAttributedString 并赋值
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict];




        通过对比两个例子可以看出，方式一比较容易处理复杂的格式，但是属性设置比较繁多复杂，而方式二的属性设置比较简单明了，却不善于处理复杂多样的格式控制，但是不善于并不等于不能，可以通过属性字符串分段的方式来达到方式一的效果，如下：

 //方式二的分段处理
 //第一段
 NSDictionary *attrDict1 = @{ NSFontAttributeName: [UIFont fontWithName: @"Zapfino" size: 15],
                              NSForegroundColorAttributeName: [UIColor blueColor] };
 NSAttributedString *attrStr1 = [[NSAttributedString alloc] initWithString: [originStr substringWithRange: NSMakeRange(0, 4)] attributes: attrDict1];

 //第二段
 NSDictionary *attrDict2 = @{ NSFontAttributeName: [UIFont fontWithName: @"Zapfino" size: 15],
                              NSForegroundColorAttributeName: [UIColor redColor] };
 NSAttributedString *attrStr2 = [[NSAttributedString alloc] initWithString: [originStr substringWithRange: NSMakeRange(4, 3)] attributes: attrDict2];

 //第三段
 NSDictionary *attrDict3 = @{ NSFontAttributeName: [UIFont fontWithName: @"Zapfino" size: 15],
                              NSForegroundColorAttributeName: [UIColor blackColor] };
 NSAttributedString *attrStr3 = [[NSAttributedString alloc] initWithString: [originStr substringWithRange:
                                                                             NSMakeRange(7, originStr.length - 4 - 3)] attributes: attrDict3];
 //合并
 NSMutableAttributedString *attributedStr03 = [[NSMutableAttributedString alloc] initWithAttributedString: attrStr1];
 [attributedStr03 appendAttributedString: attrStr2];
 [attributedStr03 appendAttributedString: attrStr3];

 _label03.attributedText = attributedStr03;




 @AttributedString究竟可以设置哪些属性，具体来说，有以下21个：
 // NSFontAttributeName                设置字体属性，默认值：字体：Helvetica(Neue) 字号：12
 // NSForegroundColorAttributeNam      设置字体颜色，取值为 UIColor对象，默认值为黑色
 // 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
 // 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
 // NSKernAttributeName                设定字符间距，取值为 NSNumber 对象（整数），正值间距加宽，负值间距变窄
 // NSStrikethroughStyleAttributeName  设置删除线，取值为 NSNumber 对象（整数）
 // NSStrikethroughColorAttributeName  设置删除线颜色，取值为 UIColor 对象，默认值为黑色
 // 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
 // NSUnderlineColorAttributeName      设置下划线颜色，取值为 UIColor 对象，默认值为黑色
 // NSStrokeWidthAttributeName         设置笔画宽度，取值为 NSNumber 对象（整数），负值填充效果，正值中空效果
 // NSStrokeColorAttributeName         填充部分颜色，不是字体颜色，取值为 UIColor 对象
 // NSShadowAttributeName              设置阴影属性，取值为 NSShadow 对象
 // 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：
 // NSBaselineOffsetAttributeName      设置基线偏移值，取值为 NSNumber （float）,正值上偏，负值下偏
 // NSObliquenessAttributeName         设置字形倾斜度，取值为 NSNumber （float）,正值右倾，负值左倾
 // 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
 // NSWritingDirectionAttributeName    设置文字书写方向，从左向右书写或者从右向左书写
 // 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
 // NSLinkAttributeName                设置链接属性，点击后调用浏览器打开指定URL地址
 // NSAttachmentAttributeName          设置文本附件,取值为NSTextAttachment对象,常用于文字图片混排
 // NSParagraphStyleAttributeName      设置文本段落排版格式，取值为 NSParagraphStyle 对象


 下面就一一举例说明：

 1. NSFontAttributeName


 //NSForegroundColorAttributeName 设置字体颜色，取值为 UIColor，默认为黑色

 NSDictionary *attrDict1 = @{ NSForegroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict2 = @{ NSForegroundColorAttributeName: [UIColor blueColor] };
 NSDictionary *attrDict3 = @{ NSForegroundColorAttributeName: [UIColor orangeColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];



 注意：

        NSForegroundColorAttributeName设置的颜色与UILabel的textColor属性设置的颜色在地位上是相等的，谁最后赋值，最终显示的就是谁的颜色。



 2. NSBackgroundColorAttributeName


 //NSForegroundColorAttributeName 设置字体颜色，取值为 UIColor，默认为黑色

 NSDictionary *attrDict1 = @{ NSForegroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict2 = @{ NSForegroundColorAttributeName: [UIColor blueColor] };
 NSDictionary *attrDict3 = @{ NSForegroundColorAttributeName: [UIColor orangeColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];


 //NSBackgroundColorAttributeName 设置字体所在区域背景的颜色，取值为UIColor，默认值为nil

 NSDictionary *attrDict4 = @{ NSBackgroundColorAttributeName: [UIColor orangeColor] };
 NSDictionary *attrDict5 = @{ NSBackgroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict6 = @{ NSBackgroundColorAttributeName: [UIColor cyanColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict4];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict5];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict6];




        仔细观察会发现个问题，我并没有关闭 NSForegroundColorAttributeName 属性，但是在运行结果中，所有字体的颜色都变成了默认色——黑色，这说明 NSForegroundColorAttributeName 和 NSBackgroundColorAttributeName 的低位是相等的，跟前面介绍的 textColor 一样，哪个属性最后一次赋值，就会冲掉前面的效果，若是我们把属性代码顺序交换一下


 //NSBackgroundColorAttributeName 设置字体所在区域背景的颜色，取值为UIColor，默认值为nil

 NSDictionary *attrDict4 = @{ NSBackgroundColorAttributeName: [UIColor orangeColor] };
 NSDictionary *attrDict5 = @{ NSBackgroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict6 = @{ NSBackgroundColorAttributeName: [UIColor cyanColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict4];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict5];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict6];

 //NSForegroundColorAttributeName 设置字体颜色，取值为 UIColor，默认为黑色

 NSDictionary *attrDict1 = @{ NSForegroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict2 = @{ NSForegroundColorAttributeName: [UIColor blueColor] };
 NSDictionary *attrDict3 = @{ NSForegroundColorAttributeName: [UIColor orangeColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];




 但是textColor属性可以与 NSBackgroundColorAttributeName 属性叠加


 _label01.textColor = [UIColor greenColor];
 _label02.textColor = [UIColor yellowColor];
 _label03.textColor = [UIColor blueColor];

 //NSForegroundColorAttributeName 设置字体颜色，取值为 UIColor，默认为黑色

 NSDictionary *attrDict1 = @{ NSForegroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict2 = @{ NSForegroundColorAttributeName: [UIColor blueColor] };
 NSDictionary *attrDict3 = @{ NSForegroundColorAttributeName: [UIColor orangeColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];


 //NSBackgroundColorAttributeName 设置字体所在区域背景的颜色，取值为UIColor，默认值为nil

 NSDictionary *attrDict4 = @{ NSBackgroundColorAttributeName: [UIColor orangeColor] };
 NSDictionary *attrDict5 = @{ NSBackgroundColorAttributeName: [UIColor redColor] };
 NSDictionary *attrDict6 = @{ NSBackgroundColorAttributeName: [UIColor cyanColor] };

 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict4];
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict5];
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict6];



        虽然 textColor 在 NSFontAttributeName 之前赋值，但是由于 NSFontAttributeName 的属性效果被NSBackgroundColorAttributeName 属性冲掉了，所以最终显示了 textColor 的颜色。



 3. NSLigatureAttributeName

 //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，
 //                        2 表示使用所有连体符号，默认值为 1（iOS 不支持 2）

 NSString *ligatureStr = @"flush";

 NSDictionary *attrDict1 = @{ NSLigatureAttributeName: [NSNumber numberWithInt: 0],
                              NSFontAttributeName: [UIFont fontWithName: @"futura" size: 30] };
 _label01.attributedText = [[NSAttributedString alloc] initWithString: ligatureStr attributes: attrDict1];

 NSDictionary *attrDict2 = @{ NSLigatureAttributeName: @(1),
                              NSFontAttributeName: [UIFont fontWithName: @"futura" size: 30]
                              };
 _label02.attributedText = [[NSAttributedString alloc] initWithString: ligatureStr attributes: attrDict2];
        由于要展示连体字符，所以将前面使用的带有中文的字符串换成 flush

        NSLigatureAttributeName的取值为NSNumber对象，所以不能直接将一个整数值赋给它，创建 NSNumber 对象的方法有很多，或者可以简写成 @(int)





        注意观察字母f和l之间的变化。

        感觉连写就是一个艺术字功能，当字符f和l组合使用组合符号（所谓的字形(glyph)）绘制时，看起来确实更加美观。但是并非所有的字符之间都有组合符号，事实上，只有某些字体中得某些字符的组合（如字符f和l，字符f和i等）才具有美观的组合符号。



 4. NSKernAttributeName


 //NSKernAttributeName 设定字符间距，取值为 NSNumber 对象（整数），正值间距加宽，负值间距变窄


   NSDictionary *attrDict1 = @{ NSKernAttributeName: @(-3),
                                NSFontAttributeName: [UIFont systemFontOfSize: 20]
                                };
   _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


   NSDictionary *attrDict2 = @{ NSKernAttributeName: @(0),
                                NSFontAttributeName: [UIFont systemFontOfSize: 20]
                                };
   _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


   NSDictionary *attrDict3 = @{ NSKernAttributeName: @(10),
                                NSFontAttributeName: [UIFont systemFontOfSize: 20]
                                };
   _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];






 5. NSStrikethroughStyleAttributeName


 //NSStrikethroughStyleAttributeName 设置删除线，取值为 NSNumber 对象（整数），枚举常量 NSUnderlineStyle中的值
 // NSUnderlineStyleNone   不设置删除线
 // NSUnderlineStyleSingle 设置删除线为细单实线
 // NSUnderlineStyleThick  设置删除线为粗单实线
 // NSUnderlineStyleDouble 设置删除线为细双实线


 NSDictionary *attrDict1 = @{ NSStrikethroughStyleAttributeName: @(NSUnderlineStyleSingle),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


 NSDictionary *attrDict2 = @{ NSStrikethroughStyleAttributeName: @(NSUnderlineStyleThick),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


 NSDictionary *attrDict3 = @{ NSStrikethroughStyleAttributeName: @(NSUnderlineStyleDouble),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];
 注意：

        虽然使用了枚举常量，但是枚举常量的本质仍为整数，所以同样必须先转化为 NSNumber 才能使用

        删除线和下划线使用相同的枚举常量作为其属性值

        目前iOS中只有上面列出的4中效果，虽然我们能够在头文件中发现其他更多的取值，但是使用后没有任何效果






 可以看出，中文和英文删除线的位置有所不同

        另外，删除线属性取值除了上面的4种外，其实还可以取其他整数值，有兴趣的可以自行试验，取值为 0 - 7时，效果为单实线，随着值得增加，单实线逐渐变粗，取值为 9 - 15时，效果为双实线，取值越大，双实线越粗。

 NSDictionary *attrDict1 = @{ NSStrikethroughStyleAttributeName: @(1),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


 NSDictionary *attrDict2 = @{ NSStrikethroughStyleAttributeName: @(3),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


 NSDictionary *attrDict3 = @{ NSStrikethroughStyleAttributeName: @(7),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];





 6. NSStrikethroughColorAttributeName


 //NSStrikethroughColorAttributeName 设置删除线颜色，取值为 UIColor 对象，默认值为黑色

   NSDictionary *attrDict1 = @{ NSStrikethroughColorAttributeName: [UIColor blueColor],
                                NSStrikethroughStyleAttributeName: @(1),
                                NSFontAttributeName: [UIFont systemFontOfSize:20] };
   _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


   NSDictionary *attrDict2 = @{ NSStrikethroughColorAttributeName: [UIColor orangeColor],
                                NSStrikethroughStyleAttributeName: @(3),
                                NSFontAttributeName: [UIFont systemFontOfSize:20] };
   _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


   NSDictionary *attrDict3 = @{ NSStrikethroughColorAttributeName: [UIColor greenColor],
                                NSStrikethroughStyleAttributeName: @(7),
                                NSFontAttributeName: [UIFont systemFontOfSize:20] };
   _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];






 7. NSUnderlineStyleAttributeName

     下划线除了线条位置和删除线不同外，其他的都可以完全参照删除线设置。


 //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

 NSDictionary *attrDict1 = @{ NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


 NSDictionary *attrDict2 = @{ NSUnderlineStyleAttributeName: @(NSUnderlineStyleThick),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


 NSDictionary *attrDict3 = @{ NSUnderlineStyleAttributeName: @(NSUnderlineStyleDouble),
                              NSFontAttributeName: [UIFont systemFontOfSize:20] };
 _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];





 8. NSUnderlineColorAttributeName

     可以完全参照下划线颜色设置


 //NSUnderlineColorAttributeName 设置下划线颜色，取值为 UIColor 对象，默认值为黑色

    NSDictionary *attrDict1 = @{ NSUnderlineColorAttributeName: [UIColor blueColor],
                                 NSUnderlineStyleAttributeName: @(NSUnderlineStyleSingle),
                                 NSFontAttributeName: [UIFont systemFontOfSize:20] };
    _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


    NSDictionary *attrDict2 = @{ NSUnderlineColorAttributeName: [UIColor orangeColor],
                                 NSUnderlineStyleAttributeName: @(NSUnderlineStyleThick),
                                 NSFontAttributeName: [UIFont systemFontOfSize:20] };
    _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


    NSDictionary *attrDict3 = @{ NSUnderlineColorAttributeName: [UIColor greenColor],
                                 NSUnderlineStyleAttributeName: @(NSUnderlineStyleDouble),
                                 NSFontAttributeName: [UIFont systemFontOfSize:20] };
    _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];






 9. NSStrokeWidthAttributeName


 //NSStrokeWidthAttributeName 设置笔画宽度，取值为 NSNumber 对象（整数），负值填充效果，正值中空效果

   NSDictionary *attrDict1 = @{ NSStrokeWidthAttributeName: @(-3),
                                NSFontAttributeName: [UIFont systemFontOfSize:30] };
   _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


   NSDictionary *attrDict2 = @{ NSStrokeWidthAttributeName: @(0),
                                NSFontAttributeName: [UIFont systemFontOfSize:30] };
   _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


   NSDictionary *attrDict3 = @{ NSStrokeWidthAttributeName: @(3),
                                NSFontAttributeName: [UIFont systemFontOfSize:30] };
   _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];






 10. NSStrokeColorAttributeName


 //NSStrokeColorAttributeName 填充部分颜色，不是字体颜色，取值为 UIColor 对象

    NSDictionary *attrDict1 = @{ NSStrokeWidthAttributeName: @(-3),
                                 NSStrokeColorAttributeName: [UIColor orangeColor],
                                 NSFontAttributeName: [UIFont systemFontOfSize:30] };
    _label01.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict1];


    NSDictionary *attrDict2 = @{ NSStrokeWidthAttributeName: @(0),
                                 NSStrokeColorAttributeName: [UIColor blueColor],
                                 NSFontAttributeName: [UIFont systemFontOfSize:30] };
    _label02.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict2];


    NSDictionary *attrDict3 = @{ NSStrokeWidthAttributeName: @(3),
                                 NSStrokeColorAttributeName: [UIColor greenColor],
                                 NSFontAttributeName: [UIFont systemFontOfSize:30] };
    _label03.attributedText = [[NSAttributedString alloc] initWithString: originStr attributes: attrDict3];