title: the program do not access ValidatingEditor and InvalidValueException
body: <p>I am using DevExpress DataGrid
  I'm filling it from excel.. If the user keep the field Name empty i need to give him an error message.. this my code:</p>
  
  <pre><code>using DevExpress.XtraGrid.Views.Base;
  using DevExpress.XtraGrid.Columns;
  using DevExpress.XtraEditors.Controls;
  using DevExpress.XtraGrid.Views.Grid;
  
  string FirstName = "First Name";
  string FatherName = "Father Name";
  string LastName = "Last Name";
  private void simpleButton1_Click(object sender, System.EventArgs e)
      {
          try
          {
              OleDbConnection con = new OleDbConnection();
              con.ConnectionString = "Provider=Microsoft.Ace.OLEDB.12.0;Data Source=C:\\Users\\pc\\Documents\\Emp.xlsx;Extended Properties=\"Excel 12.0;HDR=Yes\"";
  
              con.Open();
              DataTable dtSchema;
              dtSchema = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
              OleDbCommand Command = new OleDbCommand ("select * FROM [" + dtSchema.Rows[0]["TABLE_NAME"].ToString() + "]", con);
              OleDbDataAdapter da = new OleDbDataAdapter(Command);
              DataSet ds = new DataSet ();
              da.Fill(ds);
              dataGrid1.DataSource = ds.Tables[0];
          }
          catch (Exception ex)
          {
              MessageBox.Show(ex.Message);
          }   
  
  private void gridView3_ValidatingEditor(object sender, DevExpress.XtraEditors.Controls.BaseContainerValidateEditorEventArgs e)
      {
          GridView view = sender as GridView;
          if(view.FocusedColumn.FieldName == "FirstName") 
          {
              string FirName = (e.Value.ToString());
              if(FirName == null) 
              {
                  e.Valid = false;
                  e.ErrorText = "Enter a First Name";
              }
          }
      }
  
  
  
  private void gridView3_InvalidValueException(object sender, DevExpress.XtraEditors.Controls.InvalidValueExceptionEventArgs e)
      {
          //Do not perform any default action 
          e.ExceptionMode = DevExpress.XtraEditors.Controls.ExceptionMode.NoAction;
          //Show the message with the error text specified 
          MessageBox.Show(e.ErrorText);
      }
  </code></pre>
  
  <p>The problem is when I run the program.. the code do not access this code and it's not showing an error..
  Could someone notice where's my fault ?
  Thank you so much</p>