将查询字符串作为路径值字典添加到ActionLink

Question

我正在尝试创建一个ActionLink来从网格中导出数据。网格由查询字符串中的值过滤。以下是网址的示例：

http://www.mysite.com/GridPage?Column=Name&Direction=Ascending&searchName=text

以下是将我的ActionLink添加到页面的代码：

@Html.ActionLink("Export to Excel",    // link text
    "Export",                          // action name
    "GridPage",                        // controller name
    Request.QueryString.ToRouteDic(),  // route values
    new { @class = "export"})          // html attributes

显示链接时，网址为：

http://www.mysite.com/GridPage/Export?Count=3&Keys=System.Collections.Generic.Dictionary%602%2BKeyCollection%5BSystem.String%2CSystem.Object%5D&Values=System.Collections.Generic.Dictionary%602%2BValueCollection%5BSystem.String%2CSystem.Object%5D

我做错了什么？

Answer 1

试试这个：

我不确定这是最干净或最正确的方法，但确实有效

我没有使用你的扩展方法。你必须重新整合：

@{ 
    RouteValueDictionary tRVD = new RouteValueDictionary(ViewContext.RouteData.Values);
    foreach (string key in Request.QueryString.Keys ) 
    { 
        tRVD[key]=Request.QueryString[key].ToString();
    }
}

然后

@Html.ActionLink("Export to Excel",    // link text
"Export",                          // action name
"GridPage",                      // controller name
tRVD, 
new Dictionary<string, object> { { "class", "export" } }) // html attributes

结果

使用类导出

Answer 2

如果你看这里： http://msdn.microsoft.com/en-us/library/system.web.mvc.html.linkextensions.actionlink.aspx

//You are currently using:
ActionLink(HtmlHelper, String, String, String, Object, Object)
//You want to be using:
ActionLink(HtmlHelper, String, String, String, RouteValueDictionary, IDictionary<String, Object>)

Answer 3

How do I get the QueryString values into a the RouteValueDictionary using Html.BeginForm()?

的交叉发布

这是一个帮助扩展，因此您可以在接受RouteValueDictionary的任何方法中转储查询字符串。

/// <summary>
/// Turn the current request's querystring into the appropriate param for <code>Html.BeginForm</code> or <code>Html.ActionLink</code>
/// </summary>
/// <param name="html"></param>
/// <returns></returns>
/// <remarks>
/// See discussions:
/// * https://stackoverflow.com/questions/4675616/how-do-i-get-the-querystring-values-into-a-the-routevaluedictionary-using-html-b
/// * https://stackoverflow.com/questions/6165700/add-query-string-as-route-value-dictionary-to-actionlink
/// </remarks>
public static RouteValueDictionary QueryStringAsRouteValueDictionary(this HtmlHelper html)
{
    // shorthand
    var qs = html.ViewContext.RequestContext.HttpContext.Request.QueryString;

    // because LINQ is the (old) new black
    return qs.AllKeys.Aggregate(new RouteValueDictionary(html.ViewContext.RouteData.Values),
        (rvd, k) => {
            // can't separately add multiple values `?foo=1&foo=2` to dictionary, they'll be combined as `foo=1,2`
            //qs.GetValues(k).ForEach(v => rvd.Add(k, v));
            rvd.Add(k, qs[k]);
            return rvd;
        });
}

Answer 4

您也可以像这样从CopyTo尝试System.Collections.Specialized：

var queryParams = new Dictionary<string, object>();
Request.QueryString.CopyTo(queryParams);
var routeValueDictionary = new RouteValueDictionary(queryParams);

Answer 5

这是一个固定版本，也可以处理相同密钥多次出现的情况：

public static RouteValueDictionary QueryStringToRouteValueDictionary(this HtmlHelper html)
{
   var qs = html.ViewContext.RequestContext.HttpContext.Request.QueryString;

   return qs.AllKeys.Aggregate(new RouteValueDictionary(html.ViewContext.RouteData.Values),
    (rvd, k) =>
   {
     // get values
     var values = qs.GetValues(k);
     // if only one value simply add it
     if (values.Length == 1)
     {
       rvd.Add(k, values[0]);
     }
     else
     {
       // an array has to be add using the syntax <k>[<i>] for the key values, where k is the key itself and i is the counter
       for (var i = 0; i < values.Length; ++i)
       {
         rvd.Add($"{k}[{i}]", values[i]);
       }
     }
     return rvd;
  });
}