c# - ASP.NET DataPager 不保留 QueryString 参数顺序

Question

我有一个 ListView 和一个 DataPager 按钮中的分页 (1,2,3,...) 不保留 的顺序querystring 中的 >parameters 这在 SEO 上下文中是一件坏事(机器人认为它是重复的内容)。

即如果我的页面是:

Test.aspx?r=8&type=10
the pager buttons show:
Test.aspx?type=8&r=10&page=1
Test.aspx?type=8&r=10&page=2

等等...我认为控件按字母顺序对它们进行排序？

我试图覆盖控件 PreRender() 事件上的那些 URL，但它仍然呈现 URL 如上所述...

有没有人遇到过这个问题？？

谢谢。

ASPX:

  <asp:ListView ID="ListViewSearchResults" runat="server"  GroupItemCount="3" 
                    OnItemDataBound="ListViewSearchResults_ItemDataBound"        
   OnPagePropertiesChanging="ListViewSearchResults_PagePropertiesChanging" >
   ......
                </asp:ListView>

.....

    <asp:DataPager ID="ListViewPager" runat="server"  QueryStringField="page"          
    OnDataBinding="ListViewPager_DataBinding" OnPreRender="ListViewPager_PreRender"
    PagedControlID="ListViewSearchResults" PageSize="21"  >
    <Fields>
    <asp:NextPreviousPagerField  ShowFirstPageButton="true"          
    ShowPreviousPageButton="false" ShowNextPageButton="false"       
     ShowLastPageButton="false" ButtonCssClass="pagingright1"   ButtonType="Link"     
     FirstPageText=""  />
     <asp:NextPreviousPagerField ShowFirstPageButton="false"      
     ShowPreviousPageButton="true"   ShowNextPageButton="false" 
     ShowLastPageButton="false" ButtonCssClass="pagingright2"   ButtonType="Link" 
     PreviousPageText="" />                      
                    <asp:NumericPagerField  ButtonType="Link" CurrentPageLabelCssClass="pagingcurrent"  RenderNonBreakingSpacesBetweenControls="false" ButtonCount="10" />                       
                <asp:NextPreviousPagerField  ShowFirstPageButton="false" ShowPreviousPageButton="false" ShowNextPageButton="true" ShowLastPageButton="false" ButtonCssClass="pagingleft2"   ButtonType="Link"  NextPageText="" />
                <asp:NextPreviousPagerField ShowFirstPageButton="false" ShowPreviousPageButton="false"   ShowNextPageButton="false" ShowLastPageButton="true" ButtonCssClass="pagingleft1"   ButtonType="Link" LastPageText="" />

            </Fields>
        </asp:DataPager>

CS:尝试以编程方式修复链接

    private void FixAllPagerLinks(string FixedUrl)
    {

    foreach (Control c in ListViewPager.Controls)
    {
        if(c.HasControls()) 
        {
            if(c.Controls[0] is HyperLink)
            {
                string PageParam = string.Empty; 
                string CurrentUrl = ((HyperLink)c.Controls[0]).NavigateUrl;
                char[] pageparam = new char[CurrentUrl.Length - CurrentUrl.IndexOf("page")];                    
                CurrentUrl.CopyTo(CurrentUrl.IndexOf("page"), pageparam, 0, CurrentUrl.Length - CurrentUrl.IndexOf("page"));
                PageParam = new string(pageparam);
                ((HyperLink)c.Controls[0]).NavigateUrl = string.Format("/{0}&{1}", FixedUrl , PageParam);
            }
        }
    }
}

    // in the DataPager PreRender Event nothing happen
    //but on page prerender event  it show the correct links but after 
    //clicking on next page in the pager it's messed up again
    protected override void OnPreRender(EventArgs e)
    {
    //getting the URL
    string NextPageurl = ((System.Web.UI.WebControls.HyperLink)        
    (ListViewPager.Controls[0].Controls[0])).NavigateUrl;
    //removing the page=1 to get the Basic url of the link
        NextPageurl = NextPageurl.Replace("&page=1", string.Empty).Replace("?page=1", string.Empty);
        string FullFixedUrl = FixQueryStringParameters(NextPageurl );
    FixAllPagerLinks(FullFixedUrl);
    }



private string FixQueryStringParameters(string QueryWithParams)
{
    string returnQueryStringParams = string.Empty;

    string p1 = string.Empty;
    string p2 = string.Empty;
    string p3 = string.Empty;
    Dictionary<string, string> QSKeyValuePairs = new Dictionary<string, string>();

    if (QueryWithParams.Split('?').Length > 1)
    {
        string parameters = QueryWithParams.Split('?')[1];

        if (parameters.Split('&').Length > 1)
        {
            p1 = parameters.Split('&')[0];
            QSKeyValuePairs.Add(p1.Split('=')[0], p1.Split('=')[1]);
            p2 = parameters.Split('&')[1];
            QSKeyValuePairs.Add(p2.Split('=')[0], p2.Split('=')[1]);

            if (parameters.Split('&').Length > 2)
            {
                p3 = parameters.Split('&')[2];
                QSKeyValuePairs.Add(p3.Split('=')[0], p3.Split('=')[1]);
            }
        }
    }

Answer 1

解决方法是将修改url的代码放在相关ListView的DataBound事件中。这是我执行此操作的代码

ASPX:

<asp:DataPager PagedControlID="_lvCategoryProduct" PageSize="3" ID="dpProducts" runat="server" QueryStringField="p">
    <Fields>
        <asp:NextPreviousPagerField ButtonCssClass="lnkPager bold" PreviousPageText="Previous" ButtonType="Link" ShowFirstPageButton="False" ShowNextPageButton="False" ShowPreviousPageButton="true" />
        <asp:NumericPagerField CurrentPageLabelCssClass="selectedPager" NumericButtonCssClass="lnkPager pagerNumber" />
        <asp:NextPreviousPagerField ButtonCssClass="lnkPager bold" NextPageText="Next" ButtonType="Link" ShowLastPageButton="False" ShowNextPageButton="True" ShowPreviousPageButton="False" />
    </Fields>
</asp:DataPager>
<asp:ListView ID="_lvCategoryProduct" runat="server" GroupItemCount="3" ItemPlaceholderID="_phItems" GroupPlaceholderID="_phGroups">
    ...
</asp:ListView>

页面代码隐藏:

protected void Page_Load(object sender, EventArgs e)
{
    _lvCategoryProduct.DataBound += _lvCategoryProduct_DataBound;
}
protected void _lvCategoryProduct_DataBound(object sender, EventArgs e)
{
    if (!String.IsNullOrEmpty(_dpProducts.QueryStringField))
    {
        Common.SetDataPagerUrls(_dpProducts);
    }
}

“通用”对象中的方法

/// <summary>
/// Method to change DataPager URLs so they keep the URL Rewriting pattern
/// Code adapted from http://weblogs.asp.net/anasghanem/archive/2009/10/08/programmatically-modifying-the-hyperlinks-in-the-datapager-control.aspx
/// </summary>
/// <param name="pager">The DataPager for which we modify the URLS</param>    
static public void SetDataPagerUrls(DataPager pager)
{
    string queryStringField = pager.QueryStringField;

    //Rewrited URL is in Page.Request.RawUrl
    string rawUrl = pager.Page.Request.RawUrl;
    //Get the value of the current page =>  abc.aspx?[queryStringField]=[X]
    string currentQueryStringValue = pager.Page.Request[queryStringField];

    //Remove the current page querystring from the URL
    rawUrl = rawUrl.Replace(queryStringField + "=" + currentQueryStringValue,"");        
    //Remove the trailing "?" or "&"        
    if (rawUrl.EndsWith("?") || rawUrl.EndsWith("&"))
    {
        rawUrl = rawUrl.Substring(0, rawUrl.Length - 1);
    }

    string queryStringValue = "";    
    //Loop through the DataPager HyperLinks to modify the NavigateUrl   
    foreach (DataPagerFieldItem Pitem in pager.Controls)
    {
        foreach (Control c in Pitem.Controls)
        {
            if (c is HyperLink)
            {
                HyperLink link = c as HyperLink;
                //Get the page value for the link NavigateUrl
                queryStringValue = GetQueryStringNumericValue(queryStringField, link.NavigateUrl);

                //Set the new URL
                link.NavigateUrl = rawUrl;
                if (link.NavigateUrl.Contains("?"))
                {
                     link.NavigateUrl += "&";
                }
                else
                {
                     link.NavigateUrl += "?";
                }
                link.NavigateUrl += queryStringField + "=" + queryStringValue;                    
            }
        }
    } 
}

/// <summary>
/// Gets a numeric value of a querystring parameter in a URL
/// </summary>
/// <param name="queryStringField">The name of the querystring field</param>
/// <param name="url">The URL in which the querystring value must be found</param>
/// <returns></returns>
static protected string GetQueryStringNumericValue(string queryStringField, string url)
{
    string returnValue = "";
    //Regular expression will match value like "p=9" in a url like "abc.aspx?p=9" or "abc.aspx?a=1&p=9&..."
    string pat = queryStringField + @"=[0-9]+";
    Regex r = new Regex(pat, RegexOptions.IgnoreCase);
    MatchCollection m = r.Matches(url);
    if (m.Count > 0)
    {
        //Remove the "[parameter]=" to keep only the value
        returnValue = m[0].Value.Replace(queryStringField + "=", "");
    }
    return returnValue;
}