ASP.NET 分页导航条

protected static string Paging(int pageIndex, int pageCount)
{
    string url = HttpContext.Current.Request.RawUrl;            
    if (url.IndexOf("?") != -1)
    {
        if (url.LastIndexOf("?page") != -1)
        {
            url = url.Substring(0, url.LastIndexOf('?'));
            url += "?";
        }
        else
            url += "&";
    }
    else
    {
        url += "?";
    }
 
    pageIndex = TypeConverter.StrToInt(HttpContext.Current.Request.QueryString["page"].ToString());
                 
    int start = 1;
    int end = 5;
    int prev = 0;
    int next = 0;
    StringBuilder html = new StringBuilder();
 
    if (pageIndex < 1) //页码
    {
        pageIndex = 1;
    }
    if (pageIndex > pageCount) //总页数
    {
        pageIndex = pageCount;
    }
 
    next = pageIndex + 1;
    prev = pageIndex - 1;
 
    if (pageIndex > 3)
    {
        start = pageIndex - 2;
        end = pageIndex + 2;
    }
 
    if (start < 1)
    {
        start = 1;
    } //为了避免输出的时候产生负数，设置如果小于就从序号开始
 
    if (pageCount < end)
    {
        end = pageCount;
    }
 
    if (pageIndex > 1)
    {
        html.AppendLine("<a href=\"" + url + "page=1\">首页</a>");
        html.AppendLine("<a href=\"" + url + "page=" + prev + "\">上一页</a>");
    }
 
    for (int i = start; i <= end; i++)
    {
        if (pageIndex == i)
            html.AppendLine("<span><a href=\"" + url + "page=" + i.ToString() + "\">" + i.ToString() + "</a></span>");
        else
            html.AppendLine("<a href=\"" + url + "page=" + i.ToString() + "\">" + i.ToString() + "</a>");
    }
 
    if (pageIndex != pageCount)
    {
        html.AppendLine("<a href=\"" + url + "page=" + next + "\">下一页</a>");
        html.AppendLine("<a href=\"" + url + "page=" + pageCount + "\">尾页</a>");
    }
 
    return html.ToString();
}