CODEWITHSUNDEEP
c#.netasp.netasp.net-mvc-3
Henrik Stenbæk
Henrik Stenbæk

Reputation: 4082

Why is the return value of Request.Form.ToString() different from the result of NameValueCollection.ToString()

It seems like the ToString () in HttpContext.Request.Form is decorated so the result is different from the one returned from ToString() whencalled directly on a NameValueCollection:

NameValueCollection nameValue = Request.Form;
string requestFormString = nameValue.ToString();

NameValueCollection mycollection = new NameValueCollection{{"say","hallo"},{"from", "me"}};
string nameValueString = mycollection.ToString();

return "RequestForm: " + requestFormString + "<br /><br />NameValue: " + nameValueString;

The result is as the following:

RequestForm: say=hallo&from=me

NameValue: System.Collections.Specialized.NameValueCollection

How can I get "string NameValueString = mycollection.ToString();" to return "say=hallo&from=me"?

Upvotes: 11

Views: 10272

Answers (3)

Brady Moritz
Brady Moritz

Reputation: 8903

Another method that works well: 

var poststring = new System.IO.StreamReader(Request.InputStream).ReadToEnd();

Upvotes: 1

dlev
dlev

Reputation: 48596

The reason you don't see the nicely formatted output is because Request.Form is actually of type System.Web.HttpValueCollection. This class overrides ToString() so that it returns the text you want. The standard NameValueCollection does not override ToString(), and so you get the output of the object version.

Without access to the specialized version of the class, you'll need to iterate the collection yourself and build up the string:

StringBuilder sb = new StringBuilder();

for (int i = 0; i < mycollection.Count; i++)
{
   string curItemStr = string.Format("{0}={1}", mycollection.Keys[i],
                                                 mycollection[mycollection.Keys[i]]);
   if (i != 0)
       sb.Append("&");
   sb.Append(curItemStr);
}

string prettyOutput = sb.ToString();

Upvotes: 9

Donut
Donut

Reputation: 112855

You need to iterate over mycollection and build a string up yourself, formatted the way that you want it. Here's one way to do it:

StringBuilder sb = new StringBuilder();

foreach (string key in mycollection.Keys)
{
   sb.Append(string.Format("{0}{1}={2}",
      sb.Length == 0 ? string.Empty : "&",
      key,
      mycollection[key]));
}

string nameValueString = sb.ToString();

The reason that simply calling ToString() on your NameValueCollection does not work is that the Object.ToString() method is what's actually being called, which (unless overridden) returns the object's fully qualified type name. In this case, the fully qualified type name is "System.Collections.Specialized.NameValueCollection".

Upvotes: 1

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