Hi Mike:

I have been trying to control the VisiblePosition of the columns in an Ultragrid (winforms) using an attribute on the DataSource's underlying type. The VisiblePosition doesn't seem to take - the columns result in an apparantly random order:

<snip>
foreach(var band in grid.DisplayLayout.Bands)
{
 PropertyDescriptorCollection propertyDescriptions = null;
 propertyDescriptions = ListBindingHelper.GetListItemProperties(grid.DataSource, band.Key, null);
 foreach (PropertyDescriptor propertyDescriptor in propertyDescriptions)
 {
  var attribute = propertyDescriptor.Attributes[typeof(DisplayAttribute)] as DisplayAttribute;
  DecorateGrid(propertyDescriptor, attribute, grid, band.Key);
 }
}
</snip>

where

private static void DecorateGrid(PropertyDescriptor propertyDescriptor, DisplayAttribute displayAttribute, UltraGridBase ultraGrid1, string bandKey)
{
 var name = propertyDescriptor.Name;
 ultraGrid1.DisplayLayout.Bands[bandKey].Columns[name].Header.VisiblePosition =   displayAttribute.VisiblePosition;
}

If it is still true in 2009.2 that we must set the column VisiblePosition in the order of the properties of the datasource type, due to how WinGrid uses reflection internally, then it seems to me that I need to go with the .Columns.FromKey[name].Move(#) strategy, and that my strategy will not work. Do you concur?

The seemingly random order is caused by the fact that your code is setting the Visible position in a random order. :)

You have to set the VisiblePosition of each column in order from 0 up. Otherwise, you run the risk that setting the VisiblePosition on a later column will alter the position of an earlier one.

In other words, set the column you want in position 0 first. Then the column you want in position 1, then 2, etc.

Mike,

Is there no way to overcome this limitation?  We have some code that we use to dynamically set order on columns.  Come to find, it is what you describe above that is most likely causing this code to have troubles.  If there is no way around this, we'll have to rewrite some plumbing to allow the column positions to be assigned in order.  Perhaps a newer version has created some solution for this? We are on version 9.1.20091.2012.

Thanks.

Matt

Hi Matt,

No, there's no way around this. What I would do is create some structure that holds a column (or the key) and the VisiblePosition that you ultimately want. Then you populate a list of those structures that has an item for each column. You can then sort the list by the visible positions and loop through them in order to set them on the real columns.