Registry setting to exclude specific processes from UI Automation

HI Surya_Narayana​

Thanks for the suggestions! However, the filtering itself is being blocked by an applicaiton that is in hang state, so we don't have any solution of now. You basically cannot filter and exclude certain UIA elements using process id for example since the UIA query itself communicates with a provider.

I tested the PropertyCondition filtering approach and confirmed that it still hangs when problematic providers are present. 

A potential solution could mean that UIA filtering by ProcessId/ProcessName bypasses provider interaction entirely, since any potential communication with a laggy provider implementation can cause system-wide hangs.

This could potentially work at the low level where UIA injects providers into applications, preventing problematic providers from being loaded entirely. This would help screen readers, test frameworks, and enterprise automation tools avoid system-wide blocking from single bad providers.

For example, I have a blocking app that freezes the main UI thread for 15 seconds to simulate a problematic app.

While this app is in hang, you cannot for example query or work with other elements despite filtering.

HashSet<string> excludedProcessNames = new HashSet<string>();
excludedProcessNames.Add("BlockingApp");

var excludedPids = Process.GetProcesses()
                          .Where(p => excludedProcessNames.Contains(p.ProcessName, StringComparer.OrdinalIgnoreCase))
                          .Select(p => p.Id)
                          .ToArray();

Condition[] conditions = excludedPids.Select(pid =>
    new NotCondition(new PropertyCondition(AutomationElement.ProcessIdProperty, pid))
).ToArray();

var combinedCondition = new AndCondition(conditions);

var elements = AutomationElement.RootElement.FindAll(TreeScope.Children, combinedCondition);

foreach (AutomationElement element in elements)
{
    Console.WriteLine(element.Current.ProcessId);
}
Console.ReadKey();