title: How to fix Error does not contain a definition for 'context' and no accessible extension method 'context' accepting a first argument type
body: <p><strong>I am using visual studio 2019 and i am working with grid view control and i am getting error</strong>:</p>
  
  <blockquote>
    <p>Severity Code Description Project File Line Suppression State Error CS1061 'admin_register_qc_team_default_aspx' does not contain a definition for 'Context' and no accessible extension method 'Context' accepting a first argument of type 'admin_register_qc_team_default_aspx' could be found (are you missing a using directive or an assembly reference?)    4_Admin_Register_QC_Team_Default.aspx D:\Balco_QC (2)\Balco_QC\Balco_QC\Admin\Register_QC_Team\Default.aspx 231 Active </p>
  </blockquote>
  
  <p>initially i din't face error, my code was working but after some changes in grid view i am getting this error  </p>
  
  <p>Don't know why this error comes after a hours again and again      </p>
  
  <pre><code>&lt;asp:UpdatePanel ID="upd" runat="server" UpdateMode="Always"&gt;
    &lt;ContentTemplate&gt;
         &lt;asp:GridView runat="server" ID="grdRegister" class="table table-striped table-bordered" AutoGenerateColumns="false"&gt;
             &lt;Columns&gt;
                 &lt;asp:TemplateField HeaderText="ID" ItemStyle-Width="30"&gt;
                 &lt;ItemTemplate&gt;
                 &lt;asp:Label runat="server" Text='&lt;%# Eval("ID") %&gt;' ID="lblID"&gt;&lt;/asp:Label&gt;
                 &lt;/ItemTemplate&gt;
              &lt;/asp:TemplateField&gt;
                  &lt;asp:TemplateField HeaderText="Employee Type" ItemStyle-Width="150"&gt;
                 &lt;ItemTemplate&gt;
                     &lt;asp:DropDownList ID="ddlEmployeeType" runat="server" class="form-control" AutoPostBack="true" OnSelectedIndexChanged="ddlPub_SelectedIndexChanged"&gt;
                          &lt;asp:ListItem Value=""&gt;--Select--&lt;/asp:ListItem&gt;
                          &lt;asp:ListItem Value="Employee"&gt;Employee&lt;/asp:ListItem&gt;
                          &lt;asp:ListItem Value="Contractor"&gt;Contractor&lt;/asp:ListItem&gt;
                     &lt;/asp:DropDownList&gt;
                  &lt;/ItemTemplate&gt;
             &lt;/asp:TemplateField&gt;
             &lt;/Columns&gt;
         &lt;/asp:GridView&gt;
     &lt;/ContentTemplate&gt;
  &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>Please help me any idea ??
  I am getting error in Label Control (Eval) and i deleted whole line and again write same 
  I do following:</p>
  
  <p>Clean solution in VisualStudio</p>
  
  <p>Close VisualStudio</p>
  
  <p>Delete all "bin" and "obj" Folders (from the whole solution) manually</p>
  
  <p>Delete "packages" Folder manually</p>
  
  <p>Restart VisualStudio</p>
  
  <p>Rebuild all but no any changes</p>