Hello Suraj, 

Thank you for contacting Infragistics. Are you trying to expand all the records on load? I don't experience any delay when simply loading, in either 15.1 or 18.2, but if you are trying to expand then all the hierarchies then it would be noticeable. 

However, if you are trying to expand all the records, you can handle the grid's IntializeRecord event and  use a Dispatcher.BeginInvoke and perform one of the grid's commands called ToggleRecordIsExpanded. This will prevent any "lock-up" behavior you might be seeing. 

eg. 

 private void XamDataGrid1_InitializeRecord(object sender, Infragistics.Windows.DataPresenter.Events.InitializeRecordEventArgs e)
        {
            Dispatcher.BeginInvoke((Action)(() =>
            {
                XamDataGrid1.ExecuteCommand(DataPresenterCommands.ToggleRecordIsExpanded, e.Record);

            }));
        }

I attached a sample, using your XML, that demonstrates this. Please review it and let me know how long it takes for the data to load or if you have any questions.

3542.WpfApp1.zip

hi Michael,

I tried with your sample. but you made the sample in .net framework 4.7.2. with Infragistics dll v 18.1.
where as we are using .net framework 4.6.2 with 15.1. does this makes the difference in loading time and hang issue, because the same I am experiencing in your sample also. I just made some changes, I am loading data on button click only. Also I am using xamdatagrid with simple row wise record.

* I could not found any button to upload the sample, so I am uploading the code. Please made changes  .net framework 4.6.2 with 15.1.  in the same sample 3542.WpfApp1.zip : 

C# :-----------------------------

namespace WpfApp1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();

}

private void XamDataGrid1_InitializeRecord(object sender, Infragistics.Windows.DataPresenter.Events.InitializeRecordEventArgs e)
{
Dispatcher.BeginInvoke((Action)(() =>
{
XamDataGrid1.ExecuteCommand(DataPresenterCommands.ToggleRecordIsExpanded, e.Record);

}));
}

private void Button_Click(object sender, RoutedEventArgs e)
{
XmlDocument doc = new XmlDocument();
doc.Load(@"..\\..\\XML\\dataset.xml");

// prepare xmldataprovider
XmlDataProvider provider = new XmlDataProvider();

if (provider != null)
{
provider.Document = doc;
provider.XPath = "";

// replicated binding code in code-behind
Binding binding = new Binding();
binding.Source = provider;
binding.XPath = "";

// bind to xamdatagrid
XamDataGrid1.SetBinding(XamDataGrid.DataSourceProperty, binding);
}
}
}
}

XAML:------------------

<Grid x:Name="layoutRoot">
<Button Click="Button_Click" Content="Load Data" VerticalAlignment="Top"/>
<igDP:XamDataGrid x:Name="XamDataGrid1" Margin="0,20,0,0"
InitializeRecord="XamDataGrid1_InitializeRecord"
/>
</Grid>

Please confirm which build of 15.1 you are using. I do advise updating to the latest service release for 15.1 if you cannot upgrade to 18.1 at this time because we fixed a memory issue back in 15.1 specifically with updating the grid's DataSource after switching tabs. The build linked above is 2252 for 15.1.