We want to achieve our grid to display all the columns expanded to its column caption width or column data width. I have done this sample xaml to demostrate two of our issues. Please let us know if we need to set different properties to acheive similar goals.

1. When I click sort on Salary icon, Salary column should expand to fit the Ascending/Descending icon.

2. I was not able to replicate with this sample. But it happens on my project. When I have several columns in a grid, when window gets loaded, all the column is not streatched to max with Theme set to Royal Strong. But without theme it streatched properly. Just a note, we have a framework Grid which was inherited from XamDataGrid and style is applied to Framework grid.

<Window x:Class="Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:igDP="http://infragistics.com/DataPresenter"
    Title="Window1" Height="400" Width="400">
    <Grid>
        <igDP:XamDataGrid BindToSampleData="True"
                          BorderBrush="Black" BorderThickness="0.5" AutoFit="True"
                          Theme="RoyaleStrong" HorizontalAlignment="Stretch">
            <igDP:XamDataGrid.FieldSettings>
                <igDP:FieldSettings Width="Auto" />
            </igDP:XamDataGrid.FieldSettings>
        </igDP:XamDataGrid>
    </Grid>
</Window>