title: Solve the error "The ConnectionString property has not been initialized."?
body: <p>My code is view all the data in the gridview</p>
  
  <p>Web.config code is</p>
  
  <pre><code>&lt;configuration&gt;
    &lt;connectionStrings&gt;
      &lt;add name="ConStr" connectionString="DataSource=.;Integrated Security=SSPI;Initial catalog=sshopping"/&gt;
    &lt;/connectionStrings&gt;
    &lt;system.web&gt;
      &lt;compilation debug="true" targetFramework="4.5"/&gt;
      &lt;httpRuntime targetFramework="4.5"/&gt;
    &lt;/system.web&gt;
  &lt;/configuration&gt;
  </code></pre>
  
  <p>It is coded in external class</p>
  
  <pre><code>namespace DBAction
  {
      public class ViewAction
      {
          public DataSet GetAllData()
          {
                  SqlCommand cmd = DataConnection.GetConnection().CreateCommand();
                  cmd.CommandText = "Select UserName,Password,RoleName,EmailID,SecurityQuestion,SecurityAnswer,LastLogin from LoginInfo";
                  SqlDataAdapter da = new SqlDataAdapter(cmd);
                  DataSet ds = new DataSet();  
                  da.Fill(ds);
                  cmd.Dispose();
                  DataConnection.CloseConnection();
                  return ds;
          }
      }
  }
  </code></pre>
  
  <p>it is giving error in line <code>da.Fill(ds)</code>
  The code to bind data source with gridview is coded on page load like this.</p>
  
  <pre><code> DataSet ds = new ViewAction().GetAllData();
          gvLoginInfo.DataSource = ds;
          gvLoginInfo.DataBind();
  </code></pre>
  
  <p>And conectionstring code in data connection class is</p>
  
  <pre><code> public static SqlConnection GetConnection()
          {
  
              if (con == null)
              {
                  con = new SqlConnection();
                  con.ConnectionString = ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
                  con.Open();
              }
  
               return con;
          }
  </code></pre>
  
  <p>And one one error is </p>
  
  <pre><code>Exception Details: System.ArgumentException: Keyword not supported: 'datasource'.
  
  Source Error:
  
  
  Line 19:             {
  Line 20:                 con = new SqlConnection();
  Line 21:                 con.ConnectionString =ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
  Line 22:                 con.Open();
  Line 23:             }
  </code></pre>