自己創建一個NSString的類別：
創建一個回調block：typedef void(^AttributedBlock)(id data);
1.根據需求頁面需要修改一個label里面的文字顏色及大小：

/**
 currentString   當前不需要改變的文字
 chageString     當前需要改變的文字
 endString       結尾字符串
 fontSize        改變的字體大小
 stringColor     改變的顏色
 tag 1:改變顏色。2：改變大小 3.改變顏色和字體
 */

/**改變字體顏色大小*/
+(void)stringWithCurrentString:(NSString *)currentString
              withChangeString:(NSString *)chageString
                     withColor:(UIColor *)stringColor
                       withTag:(NSInteger)tag
                      withFont:(NSInteger)fontSize
                 withEndString:(NSString *)endString
                     withBlock:(AttributedBlock)block;

+(void)stringWithCurrentString:(NSString *)currentString
              withChangeString:(NSString *)chageString
                     withColor:(UIColor *)stringColor
                       withTag:(NSInteger)tag
                      withFont:(NSInteger)fontSize
                 withEndString:(NSString *)endString
                     withBlock:(AttributedBlock)block
{
    NSString * textString = [NSString stringWithFormat:@"%@%@%@",currentString,chageString,endString];
    NSInteger currentStringLength = currentString.length;
    NSInteger chageStringLength = chageString.length;
    NSMutableAttributedString * attributeString = [[NSMutableAttributedString alloc]initWithString:textString];
    if (tag == 1)//改變顏色
    {
        [attributeString addAttribute:NSForegroundColorAttributeName value:stringColor range:NSMakeRange(currentStringLength, chageStringLength)];
    }
    else if (tag == 2)
    {
        [attributeString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:fontSize]    range:NSMakeRange(currentStringLength, chageStringLength)];
    }
    else if (tag == 3)
    {
        [attributeString addAttribute:NSForegroundColorAttributeName value:stringColor range:NSMakeRange(currentStringLength, chageStringLength)];
        [attributeString addAttribute:NSFontAttributeName value:[UIFont systemFontOfSize:fontSize]    range:NSMakeRange(currentStringLength, chageStringLength)];
    }
    block(attributeString);
}

2.文字前面加圖片：

+(void)stringWithImage:(NSString *)currentString
             withBlock:(AttributedBlock)block;

+(void)stringWithImage:(NSString *)currentString
             withBlock:(AttributedBlock)block
{
    NSMutableAttributedString * attributeString = [[NSMutableAttributedString alloc]initWithString:currentString];
    NSTextAttachment *attach = [[NSTextAttachment alloc] init];
    attach.image = [UIImage imageNamed:@"需要添加的圖片"];
    attach.bounds = CGRectMake(0, -3, 15, 15);
    NSAttributedString *attachString = [NSAttributedString attributedStringWithAttachment:attach];
    [attributeString insertAttributedString:attachString atIndex:0];
    block(attributeString);
}

3.顯示價格的時候需要顯示中劃線：

/**中劃線。價格*/
+(void)stringWithLine:(NSString *)currentString
            withBlock:(AttributedBlock)block;

+(void)stringWithLine:(NSString *)currentString
            withBlock:(AttributedBlock)block
{
    NSMutableAttributedString * attributeString = [[NSMutableAttributedString alloc]initWithString:currentString];
    NSInteger currentStringLength = currentString.length;
    [attributeString addAttribute:NSStrikethroughStyleAttributeName value:@(NSUnderlineStyleSingle) range:NSMakeRange(0, currentStringLength)];
    [attributeString addAttribute:NSStrikethroughColorAttributeName value:[UIColor lightGrayColor] range:NSMakeRange(0, currentStringLength)];
    block(attributeString);
}