NSMutableAttributedString的简单用法

一直对这个类的用法有点糊涂，今天抽了一个时间研究了一下

1.首先来看系统的api（方法）

 1 @interface NSMutableAttributedString : NSAttributedString
 2
 3 - (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str;
 4 - (void)setAttributes:(nullable NSDictionary<NSString *, id> *)attrs range:(NSRange)range;
 5
 6 @end
 7
 8 @interface NSMutableAttributedString (NSExtendedMutableAttributedString)
 9
10 @property (readonly, retain) NSMutableString *mutableString;
11
12 - (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range;
13 - (void)addAttributes:(NSDictionary<NSString *, id> *)attrs range:(NSRange)range;
14 - (void)removeAttribute:(NSString *)name range:(NSRange)range;
15
16 - (void)replaceCharactersInRange:(NSRange)range withAttributedString:(NSAttributedString *)attrString;
17 - (void)insertAttributedString:(NSAttributedString *)attrString atIndex:(NSUInteger)loc;
18 - (void)appendAttributedString:(NSAttributedString *)attrString;
19 - (void)deleteCharactersInRange:(NSRange)range;
20 - (void)setAttributedString:(NSAttributedString *)attrString;
21
22 - (void)beginEditing;
23 - (void)endEditing;

2.在此呢 基本类 有两个方法3-4    又给这个NSMutableAttributedString添加了一个类别NSExtendedMutableAttributedString。简单介绍几个方法的用法

3.总的来说 共有这几种情况 3.范围替换 4.范围多属性 12.范围单属性 13.范围多属性 14.移除范围单属性 16.范围替换（用NSMutableAttributedString） 等 其他的自己尝试

4.下面是我简单的写了一点代码

 1     NSString *string = @"这是一个完整的句子吧";
 2
 3     UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 70, 250, 50)];
 4         [self.view addSubview:label];
 5
 6     //初始化一个attriburitedString对象
 7     _attributeString = [[NSMutableAttributedString alloc] initWithString:string];
 8
 9     //给这个属性添加一个属性前3个字符的背景颜色
10     NSRange orRange = NSMakeRange(0, 3);
11     [_attributeString addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:orRange];
12
13
14     //更换string的部分字符串
15     NSRange reRange = NSMakeRange(3, 2);
16     [_attributeString replaceCharactersInRange:reRange withString:@"qinguangyi"];
17
18     //添加多个属性
19     NSRange seRange = NSMakeRange(8, 5);
20     [_attributeString setAttributes:@{
21                                       NSForegroundColorAttributeName:
22                                           [UIColor redColor],
23                                       NSBackgroundColorAttributeName:
24                                           [UIColor blueColor],
25                                       } range:seRange];
26
27     NSMutableAttributedString *newAttributeString = [[NSMutableAttributedString alloc] initWithString:@"NEW"];
28
29     /* 其他属性自己尝试
30     [_attributeString replaceCharactersInRange:NSMakeRange(0, 3) withString:@"123"];
31     [_attributeString insertAttributedString:newAttributeString atIndex:0];
32     [_attributeString deleteCharactersInRange:NSMakeRange(0, 3)];
33     [_attributeString appendAttributedString:newAttributeString];
34
35     [_attributeString setAttributedString:newAttributeString];
36      */
37
38
39
40     //最简单的给label赋值的方法打点调用attributedText
41     label.attributedText = _attributeString;

5.展示出来如图