title: DotNetBrowser modify post data uwitn OnBeforeURLRequest
body: <p>Following this example : <a href="https://dotnetbrowser.support.teamdev.com/support/solutions/articles/9000110170-modifying-post-put-patch-upload-data" rel="nofollow noreferrer">https://dotnetbrowser.support.teamdev.com/support/solutions/articles/9000110170-modifying-post-put-patch-upload-data</a> , I have created the following code :</p>
  
  <pre><code>public override void OnBeforeURLRequest(BeforeURLRequestParams parameters)
      {
          bool param1Found = false;
          bool param2Found = false;
  
          if (parameters != null)
          {
              if ("POST" == parameters.Method)
              {
                  if (parameters.PostData != null)
                  {
                      if (parameters.PostData.ContentType == PostDataContentType.FORM_URL_ENCODED)
                      {
                          PostData post = parameters.PostData;
                          FormData postData2 = (FormData)parameters.PostData;
                          var mata = postData2.GetPairKeys();
                          foreach (var item in mata)
                          {
                              if (item == "abc")
                              {
                                  param1Found = true;
                              }
                              else if (item == "def")
                              {
                                  param2Found = true;
                              }
                              var coco = postData2.GetPairValues(item);
                              foreach (var item2 in coco)
                              {
                                  Console.WriteLine(item + ":" + item2);
                              }
                          }
                          if (param1Found == true &amp;&amp; param2Found == true)
                          {
                              FormData postData = (FormData)parameters.PostData;
                              postData.SetPair("abc", "undefined");
                              parameters.PostData = postData;
                          }
                      }
                  }
              }
          }
      }
  </code></pre>
  
  <p>however , I can not find my value in Chrome Developer Tools under Network tab, and for some reason the original code from the above link crashes the app (cast error).
  Am I missing something ? Can some one point me on the right direction ? Thanks.</p>