title: Displaying cellvalidation error messages under telerik winforms
body: <p>I've got a Telerik.WinControls.UI.RadGridView with multiple columns in it.
  I'm using a mix of rowvalidation and cellvalidation to validate the input I get (although for the current problem I also tried deactivating the rowvalidation but still got the same results).</p>
  
  <p>I have one daterow for which I use the cellvalidating event to validate it (else I get an exception if a user types in a wrong date). The behaviour I expected was that the error message is displayed and the cell not validated. The 2nd thing worked, but the error message ONLY gets displayed when
  I move the mouse onto the border of the cell (else it is just not shown).</p>
  
  <p>So my question would be how could I manage to achieve that the error message is shown as soon and as long as an error is found through the validation?</p>
  
  <p>Here is the cellvalidation code I use:</p>
  
  <pre><code>void MainFormGridView_CellValidating(object sender, CellValidatingEventArgs eventArgs)
  {
      var currentCell = eventArgs.Row.Cells[eventArgs.ColumnIndex];
  
      if (eventArgs.Column.Name == "OrderDate")
      {
          if (eventArgs.Value == null)
          {
              eventArgs.Cancel = true;
          }
          else
          {
              try
              {
                  DateTime dateValue;
                  if (!DateTime.TryParse(eventArgs.Value.ToString(), out dateValue))
                  {
                      eventArgs.Cancel = true;
                  }
              }
              catch
              {
                  // Error occured so validation error!
                  eventArgs.Cancel = true;
              }
          }
          if (eventArgs.Cancel)
          {
              currentCell.ErrorText = "Error no valid date! Please type in a valid date";
          }
          else
          {
              currentCell.ErrorText = string.Empty;
          }
      }
  }
  </code></pre>