public override void OnPageLoaded()
    {
        string letter = this.llCategory.FirstLetter, title = string.Empty;

        StringBuilder sbKeywords = new StringBuilder();

        switch (this.llCategory.LetterType)
        {
        case LettersType.Category:
            List <ProductCategory> listCategory = ProductCategories.GetCategoreisByPY(letter);
            if (null == listCategory || 0 == listCategory.Count)
            {
            }
            else
            {
                foreach (ProductCategory item in listCategory)
                {
                    sbKeywords.AppendFormat("{0},", item.CategoryName);
                }
            }
            title = "分类";
            break;

        case LettersType.Brand:
            List <ProductBrand> listBrand = ProductBrands.GetBrandsByPY(letter);
            if (null == listBrand || 0 == listBrand.Count)
            {
            }
            else
            {
                foreach (ProductBrand item in listBrand)
                {
                    sbKeywords.AppendFormat("{0},", item.BrandName);
                }
            }
            title = "品牌";
            break;

        case LettersType.Industry:
            List <ProductIndustry> listIndustry = ProductIndustries.GetIndustriesByPY(letter);
            if (null == listIndustry || 0 == listIndustry.Count)
            {
            }
            else
            {
                foreach (ProductIndustry item in listIndustry)
                {
                    sbKeywords.AppendFormat("{0},", item.IndustryName);
                }
            }
            title = "行业";
            break;
        }

        string keywords = sbKeywords.ToString().TrimEnd(',');

        if (string.IsNullOrEmpty(keywords))
        {
            //this.AddKeywords(keywords);
            this.AddDescription(string.Format("按照首字母进行{0}检索,首字母是{1}", title, letter.ToUpper()));

            this.ShortTitle = string.Format("首字母{0}检索{1}", title, letter.ToUpper());
        }
        else
        {
            this.AddKeywords(keywords);
            this.AddDescription(string.Format("按照首字母进行{0}检索,首字母是{1},符合条件的{0}列表如下: {2}", title, letter.ToUpper(), keywords));

            this.ShortTitle = string.Format("首字母{0}检索{1} - {2}", title, letter.ToUpper(), keywords);
        }
        this.SetTitle();
    }