Get url parameters from a string in NET

Question

I ve got a string in  NET which is actually a url   I want an easy way to get the value from a particular parameter     Normally  I d just use Request Params  theThingIWant    but this string isn t from the request   I can create a new Uri item like so   Uri myUri   new Uri TheStringUrlIWantMyValueFrom     I can use myUri Query to get the query string   but then I apparently have to find some regexy way of splitting it up   Am I missing something obvious  or is there no built in way to do this short of creating a regex of some kind  etc

User · Answer

This is probably what you want  var uri   new Uri  http   domain test Default aspx var1 true amp var2 test amp var3 3    var query   HttpUtility ParseQueryString uri Query    var var2   query Get  var2

User · Answer

Use static ParseQueryString method of System Web HttpUtility class that returns NameValueCollection   Uri myUri   new Uri  http   www example com param1 good amp param2 bad    string param1   HttpUtility ParseQueryString myUri Query  Get  param1      Check documentation at http   msdn microsoft com en-us library ms150046 aspx

User · Answer

This is actually very simple  and that worked for me             if  id     DK                         string longurl    selectServer aspx country                var uriBuilder   new UriBuilder longurl               var query   HttpUtility ParseQueryString uriBuilder Query               query  country      DK                uriBuilder Query   query ToString                longurl   uriBuilder ToString

User · Answer

I used it and it run perfectly    lt   Request QueryString  id     gt

User · Answer

Here s another alternative if  for any reason  you can t or don t want to use HttpUtility ParseQueryString     This is built to be somewhat tolerant to  malformed  query strings  i e  http   test test html empty  becomes a parameter with an empty value  The caller can verify the parameters if needed   public static class UriHelper       public static Dictionary lt string  string gt  DecodeQueryParameters this Uri uri                if  uri    null              throw new ArgumentNullException  uri             if  uri Query Length    0              return new Dictionary lt string  string gt              return uri Query TrimStart                               Split new       amp           StringSplitOptions RemoveEmptyEntries                           Select parameter   gt  parameter Split new            StringSplitOptions RemoveEmptyEntries                            GroupBy parts   gt  parts 0                                    parts   gt  parts Length  gt  2   string Join      parts  1  parts Length - 1     parts Length  gt  1   parts 1                                  ToDictionary grouping   gt  grouping Key                                        grouping   gt  string Join      grouping              Test   TestClass  public class UriHelperTest        TestMethod      public void DecodeQueryParameters                 DecodeQueryParametersTest  http   test test html   new Dictionary lt string  string gt              DecodeQueryParametersTest  http   test test html    new Dictionary lt string  string gt              DecodeQueryParametersTest  http   test test html key bla blub xml   new Dictionary lt string  string gt       key    bla blub xml                DecodeQueryParametersTest  http   test test html eins 1 amp zwei 2   new Dictionary lt string  string gt       eins    1        zwei    2                DecodeQueryParametersTest  http   test test html empty   new Dictionary lt string  string gt       empty                    DecodeQueryParametersTest  http   test test html empty    new Dictionary lt string  string gt       empty                    DecodeQueryParametersTest  http   test test html key 1 amp    new Dictionary lt string  string gt       key    1                DecodeQueryParametersTest  http   test test html key value  amp b c   new Dictionary lt string  string gt       key    value         b    c                DecodeQueryParametersTest  http   test test html key value what   new Dictionary lt string  string gt       key    value what                DecodeQueryParametersTest  http   www google com search q energy edge amp rls com microsoft en-au amp ie UTF-8 amp oe UTF-8 amp startIndex  amp startPage 1 22               new Dictionary lt string  string gt                                   q    energy edge                        rls    com microsoft en-au                        ie    UTF-8                        oe    UTF-8                        startIndex                            startPage    1 22                             DecodeQueryParametersTest  http   test test html key value key anotherValue   new Dictionary lt string  string gt       key    value anotherValue                   private static void DecodeQueryParametersTest string uri  Dictionary lt string  string gt  expected                Dictionary lt string  string gt  parameters   new Uri uri  DecodeQueryParameters            Assert AreEqual expected Count  parameters Count   Wrong parameter count  Uri   0    uri           foreach  var key in expected Keys                        Assert IsTrue parameters ContainsKey key    Missing parameter key  0   Uri   1    key  uri               Assert AreEqual expected key   parameters key    Wrong parameter value for  0   Uri   1    parameters key   uri

User · Answer

Andrew and  CZFox   I had the same bug and found the cause to be that parameter one is in fact  http   www example com param1 and not param1 which is what one would expect   By removing all characters before and including the question mark fixes this problem  So in essence the HttpUtility ParseQueryString function only requires a valid query string parameter containing only characters after the question mark as in   HttpUtility ParseQueryString    param1 good amp param2 bad      My workaround   string RawUrl    http   www example com param1 good amp param2 bad   int index   RawUrl IndexOf          if   index  gt  0       RawUrl   RawUrl Substring   index   Remove   0  1     Uri myUri   new Uri  RawUrl  UriKind RelativeOrAbsolute   string param1   HttpUtility ParseQueryString  myUri Query   Get   param1

User · Answer

You can use the following workaround for it to work with the first parameter too   var param1       HttpUtility ParseQueryString url Substring          new    0  url IndexOf       Max          Get  param1

User · Answer

if you want in get your  QueryString on Default page  Default page means your current page url    you can try  this code     string paramIl   HttpUtility ParseQueryString this ClientQueryString  Get  city

User · Answer

Or if you don t know the URL  so as to avoid hardcoding  use the AbsoluteUri  Example                get the full URL         Uri myUri   new Uri Request Url AbsoluteUri             get any parameters         string strStatus   HttpUtility ParseQueryString myUri Query  Get  status            string strMsg   HttpUtility ParseQueryString myUri Query  Get  message            switch  strStatus ToUpper                          case  OK                   webMessageBox Show  EMAILS SENT                     break              case  ER                   webMessageBox Show  EMAILS SENT  BUT         strMsg                   break

User · Answer

HttpContext Current Request QueryString Get  id

User · Answer

Use  NET Reflector to view the FillFromString method of System Web HttpValueCollection   That gives you the code that ASP NET is using to fill the Request QueryString collection

User · Answer

For anyone who wants to loop through all query strings from a string          foreach  var item in new Uri urlString  Query TrimStart      Split   amp                           var subStrings   item Split                    var key   subStrings 0               var value   subStrings 1                   do something with values

User · Answer

Looks like you should loop over the values of myUri Query and parse it from there    string desiredValue   foreach string item in myUri Query Split   amp             string   parts   item Replace          Split            if parts 0      desiredKey                   desiredValue   parts 1            break              I wouldn t use this code without testing it on a bunch of malformed URLs however   It might break on some all of these    hello html  hello html valuelesskey hello html key value hi hello html hi value  amp b c etc

[c#] Get url parameters from a string in .NET

Examples related to c#

Examples related to .net

Examples related to url

Examples related to parsing

Examples related to parameters