NSMutableAttributedString的簡單用法

一直對這個類的用法有點糊塗，今天抽了一個時間研究了一下

1.首先來看系統的api（方法）

@interface NSMutableAttributedString : NSAttributedString

- (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str;
- (void)setAttributes:(nullable NSDictionary<NSString *, id> *)attrs range:(NSRange)range;

@end

@interface NSMutableAttributedString (NSExtendedMutableAttributedString)

@property (readonly, retain) NSMutableString *mutableString;

- (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range;
- (void)addAttributes:(NSDictionary<NSString *, id> *)attrs range:(NSRange)range;
- (void)removeAttribute:(NSString *)name range:(NSRange)range;

- (void)replaceCharactersInRange:(NSRange)range withAttributedString:(NSAttributedString *)attrString;
- (void)insertAttributedString:(NSAttributedString *)attrString atIndex:(NSUInteger)loc;
- (void)appendAttributedString:(NSAttributedString *)attrString;
- (void)deleteCharactersInRange:(NSRange)range;
- (void)setAttributedString:(NSAttributedString *)attrString;

- (void)beginEditing;
- (void)endEditing;

2.在此呢 基本類 有兩個方法3-4    又給這個NSMutableAttributedString添加了一個類別NSExtendedMutableAttributedString。簡單介紹幾個方法的用法

3.總的來說 共有這幾種情況 3.范圍替換 4.范圍多屬性 12.范圍單屬性 13.范圍多屬性 14.移除范圍單屬性 16.范圍替換（用NSMutableAttributedString） 等 其他的自己嘗試

4.下面是我簡單的寫了一點代碼

    NSString *string = @"這是一個完整的句子吧";
    
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 70, 250, 50)];
        [self.view addSubview:label];
    
    //初始化一個attriburitedString對象
    _attributeString = [[NSMutableAttributedString alloc] initWithString:string];
    
    //給這個屬性添加一個屬性前3個字符的背景顏色
    NSRange orRange = NSMakeRange(0, 3);
    [_attributeString addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:orRange];
    
    
    //更換string的部分字符串
    NSRange reRange = NSMakeRange(3, 2);
    [_attributeString replaceCharactersInRange:reRange withString:@"qinguangyi"];
    
    //添加多個屬性
    NSRange seRange = NSMakeRange(8, 5);
    [_attributeString setAttributes:@{
                                      NSForegroundColorAttributeName:
                                          [UIColor redColor],
                                      NSBackgroundColorAttributeName:
                                          [UIColor blueColor],
                                      } range:seRange];
    
    NSMutableAttributedString *newAttributeString = [[NSMutableAttributedString alloc] initWithString:@"NEW"];
    
    /* 其他屬性自己嘗試
    [_attributeString replaceCharactersInRange:NSMakeRange(0, 3) withString:@"123"];
    [_attributeString insertAttributedString:newAttributeString atIndex:0];
    [_attributeString deleteCharactersInRange:NSMakeRange(0, 3)];
    [_attributeString appendAttributedString:newAttributeString];
    
    [_attributeString setAttributedString:newAttributeString];
     */
    
    
    
    //最簡單的給label賦值的方法打點調用attributedText
    label.attributedText = _attributeString;

5.展示出來如圖