#pragma mark 获取含自定义的图片的字符串
-(NSMutableAttributedString *)ImgWithString:(NSString *)string
{
    if (!string) {
        return [NSMutableAttributedString new];
    }
    NSMutableAttributedString *result = [[NSMutableAttributedString alloc] initWithString:string];
    
    //所有表情数组
    NSArray *expressionList = [[NSArray new] EmoticonArray];
    
    int i = 0;
    
    while (i < expressionList.count) {
        NSString *item = expressionList[i];
        NSRange range = [result.string rangeOfString:item];
        if(range.location == NSNotFound){
            i++;
            continue;
        }
        ImageTextAttachment *textAttachment = [[ImageTextAttachment alloc] init];
        
        //表情文本替换成图片
        UIImage * image = [UIImage imageNamed:[self stringToImageName:item]];
        
        CGSize size = [image size];
        textAttachment.bounds = CGRectMake(0, 0, size.width*16/size.height, 16);
        textAttachment.image = image;
        textAttachment.imageTag = item;

        NSAttributedString *attchString = [NSAttributedString attributedStringWithAttachment:textAttachment];
        [result replaceCharactersInRange:range withAttributedString:attchString];
    }
    return result;
}

#pragma mark 根据表情名称--得到图片名称
-(NSString *)stringToImageName:(NSString *)string
{
    NSString *result = string;
    result = [result stringByReplacingOccurrencesOfString:@"/" withString:@""];
    result = [result stringByReplacingOccurrencesOfString:@"[" withString:@""];
    result = [result stringByReplacingOccurrencesOfString:@"]" withString:@""];
    return result;
}

#pragma mark 图片转化成纯文本
-(NSString *)getPlainString {
    
    NSMutableString *plainString = [NSMutableString stringWithString:self.string];
    
    __block NSUInteger base = 0;
    
    [self enumerateAttribute:NSAttachmentAttributeName inRange:NSMakeRange(0, self.length)
                     options:0
                  usingBlock:^(id value, NSRange range, BOOL *stop) {
                      //检查类型是否是自定义NSTextAttachment类
                      if (value && [value isKindOfClass:[ImageTextAttachment class]]) {
                          //替换
                          [plainString replaceCharactersInRange:NSMakeRange(range.location + base, range.length) withString:((ImageTextAttachment *) value).imageTag];
                          //增加偏移量
                          base += ((ImageTextAttachment *) value).imageTag.length - 1;
                      }
                  }];
    
    return plainString;
}