Help with Xpath

[EtaLasquera]

I'm trying to use Xpath to do some tasks.
This is my first time who I'm trying to use a variable mixed with Xpath code, my problem is... if I put a number direct in the Xpath code, the code returns "error" if I put the same number from a variable the code returns sucess...

If I run that code on this DOM:

<div class="ng-isolate-scope" vr-pagination="" page="transacoesPage" page-quantity="transacoesPageQuantity" page-limit="pageLimit" page-change-request="changeTransacoesPage">

  <!-- paginacao v1 -->
  <nav class="text-center no-print u-legacy--hide-v2">
  <ul class="pagination">
  <li class="ng-hide" ng-show="showLeftPaginationArrow()">
  <a href="javascript:void(0)" ng-click="changePage(pagination[0].page - 1)">
  <span aria-hidden="true">
  <i class="fa fa-angle-left"></i>
  </span>
  </a>
  </li>
  <!-- ngRepeat: item in pagination | limitTo:pageLimit --><li class="ng-scope" ng-repeat="item in pagination | limitTo:pageLimit">
  <a class="ng-binding active" href="javascript:void(0)" ng-click="changePage(item.page)" ng-class="{'active':item.page === page}">1</a>
  </li><!-- end ngRepeat: item in pagination | limitTo:pageLimit --><li class="ng-scope" ng-repeat="item in pagination | limitTo:pageLimit">
  <a class="ng-binding" href="javascript:void(0)" ng-click="changePage(item.page)" ng-class="{'active':item.page === page}">2</a>
  </li><!-- end ngRepeat: item in pagination | limitTo:pageLimit -->
  <li class="ng-hide" ng-show="showRightPaginationArrow()">
  <a href="javascript:void(0)" ng-click="changePage(pagination[pageLimit].page)">
  <span aria-hidden="true">
  <i class="fa fa-angle-right"></i>
  </span>
  </a>
  </li>
  </ul>
  </nav>
  <!-- end paginacao v1 -->

  <!-- paginacao v2 -->
  <nav class="c-pagination u-legacy--hide-v1">
  <ul class="o-list-inline c-pagination">
  <li class="o-list-inline__item c-pagination__item ng-hide" ng-show="showLeftPaginationArrow()">
  <a href="javascript:void(0)" class="c-btn c-btn--icon c-btn--small" ng-click="changePage(pagination[0].page - 1)">
  <svg class="c-btn__icon c-btn__icon--default">
  <use xlink:href="#micro-arrow-left"></use>
  </svg>
  </a>
  </li>
  <!-- ngRepeat: item in pagination | limitTo:pageLimit --><li class="o-list-inline__item c-pagination__item ng-scope" ng-repeat="item in pagination | limitTo:pageLimit">
  <a class="ng-binding is-active" href="javascript:void(0)" ng-click="changePage(item.page)" ng-class="{'is-active':item.page === page}">1</a>
  </li><!-- end ngRepeat: item in pagination | limitTo:pageLimit --><li class="o-list-inline__item c-pagination__item ng-scope" ng-repeat="item in pagination | limitTo:pageLimit">
  <a class="ng-binding" href="javascript:void(0)" ng-click="changePage(item.page)" ng-class="{'is-active':item.page === page}">2</a>
  </li><!-- end ngRepeat: item in pagination | limitTo:pageLimit -->
  <li class="o-list-inline__item c-pagination__item ng-hide" ng-show="showRightPaginationArrow()">
  <a href="javascript:void(0)" class="c-btn c-btn--icon c-btn--small" ng-click="changePage(pagination[pageLimit].page)">
  <svg class="c-btn__icon c-btn__icon--default">
  <use xlink:href="#micro-arrow-right"></use>
  </svg>
  </a>
  </li>
  </ul>
  </nav>
  <!-- end paginacao v2 -->
</div>

Example code who will return error (I want to get error!)

string xpath = "(//div[@page='transacoesPage']/nav/ul/li/a[@class='ng-binding'][contains(.,'3'])";
string dothis= "rise|click";
string set ="";

return CommonCode.FindElementAndExecuteAction(instance, xpath, dothis, set);

Now, if I have a variable "counter" and it value is "3", the result is success:

string str = project.Variables["counter"].Value;
string xpath = "(//div[@page='transacoesPage']/nav/ul/li/a[@class='ng-binding'][contains(.,str])";
string dothis= "rise|click";
string set ="";
instance.Variables["test"].Value = project.Variables["counter"].Value;
return CommonCode.FindElementAndExecuteAction(instance, xpath, dothis, set);

There is a way to use a variable from zenno to use it on Xpath?
the value of variable "test" return 3...

 

[EtaLasquera]

Found error by my self.... fail in C#...
...[contains(.,"+str+")";
Done.