private IUIAutomationElement GetNearbyElement(GetElementDelegate getNextElement)
{
var currentElement = GetCurrentElement();
if (currentElement == null)
{
return(null);
}
var treeWalker = A11yAutomation.GetTreeWalker(this.TreeViewMode);
var retVal = getNextElement?.Invoke(treeWalker, currentElement);
// make sure that we skip an element from current process while walking tree.
// this code should be hit only at App level. but for sure.
if (DesktopElement.IsFromCurrentProcess(retVal))
{
var tmp = retVal;
retVal = getNextElement?.Invoke(treeWalker, retVal);
// since element is not in use, release.
Marshal.ReleaseComObject(tmp);
}
Marshal.ReleaseComObject(treeWalker);
return(retVal);
}
/// <summary>
/// Constructor DesktopElementAncestry
/// Get Ancestry Tree elements up to Desktop(at best)
/// </summary>
/// <param name="walker"></param>
/// <param name="e"></param>
public DesktopElementAncestry(TreeViewMode mode, A11yElement e, bool setMem = false)
{
this.TreeWalker = A11yAutomation.GetTreeWalker(mode);
this.TreeWalkerMode = mode;
this.Items = new List <A11yElement>();
this.SetMembers = setMem;
SetParent(e, -1);
if (Items.Count != 0)
{
this.First = Items.Last();
this.Last = Items.First();
if (this.Last.IsRootElement() == false)
{
this.Last.Children.Clear();
this.NextId = PopulateSiblingTreeNodes(this.Last, e);
}
else
{
this.NextId = 1;
}
}
Marshal.ReleaseComObject(this.TreeWalker);
}
/// <summary>
/// Populate tree by retrieving all children at once.
/// </summary>
/// <param name="rootNode"></param>
private void PopulateChildrenTreeNode(A11yElement rootNode, int startId)
{
int childId = startId;
IUIAutomationTreeWalker walker = A11yAutomation.GetTreeWalker(this.WalkerMode);
IUIAutomationElement child = (IUIAutomationElement)rootNode.PlatformObject;
if (child != null)
{
try
{
child = walker.GetFirstChildElement(child);
}
#pragma warning disable CA1031 // Do not catch general exception types
catch (Exception ex)
{
ex.ReportException();
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
#pragma warning restore CA1031 // Do not catch general exception types
while (child != null)
{
#pragma warning disable CA2000 // childNode will be disposed by the parent node
// Create child without populating basic property. it will be set all at once in parallel.
var childNode = new DesktopElement(child, true, false)
{
UniqueId = childId++
};
#pragma warning restore CA2000 // childNode will be disposed by the parent node
rootNode.Children.Add(childNode);
childNode.Parent = rootNode;
childNode.TreeWalkerMode = this.WalkerMode;
this.Elements.Add(childNode);
try
{
child = walker.GetNextSiblingElement(child);
}
#pragma warning disable CA1031 // Do not catch general exception types
catch (Exception ex)
{
ex.ReportException();
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
#pragma warning restore CA1031 // Do not catch general exception types
}
}
Marshal.ReleaseComObject(walker);
}
/// <summary>
/// Populate tree by retrieving all children at once.
/// </summary>
/// <param name="rootNode"></param>
/// <param name="parentNode"></param>
/// <param name="startChildId"></param>
private int PopulateChildrenTreeNode(A11yElement rootNode, A11yElement parentNode, int startChildId)
{
this.Elements.Add(rootNode);
rootNode.Parent = parentNode;
rootNode.TreeWalkerMode = this.WalkerMode; // set tree walker mode.
IUIAutomationTreeWalker walker = A11yAutomation.GetTreeWalker(this.WalkerMode);
IUIAutomationElement child = (IUIAutomationElement)rootNode.PlatformObject;
if (child != null)
{
try
{
child = walker.GetFirstChildElement(child);
}
#pragma warning disable CA1031 // Do not catch general exception types
catch (Exception ex)
{
ex.ReportException();
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
#pragma warning restore CA1031 // Do not catch general exception types
while (child != null && _elementCounter.TryIncrement())
{
// Create child without populating basic property. it will be set all at once in parallel.
var childNode = new DesktopElement(child, true, false);
rootNode.Children.Add(childNode);
childNode.Parent = rootNode;
childNode.UniqueId = startChildId++;
startChildId = PopulateChildrenTreeNode(childNode, rootNode, startChildId);
try
{
child = walker.GetNextSiblingElement(child);
}
#pragma warning disable CA1031 // Do not catch general exception types
catch (Exception ex)
{
ex.ReportException();
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
#pragma warning restore CA1031 // Do not catch general exception types
}
}
Marshal.ReleaseComObject(walker);
return(startChildId);
}
/// <summary>
/// Populate tree by retrieving all children at once.
/// </summary>
/// <param name="rootNode"></param>
private void PopulateChildrenTreeNode(A11yElement rootNode, int startId)
{
int childId = startId;
IUIAutomationTreeWalker walker = A11yAutomation.GetTreeWalker(this.WalkerMode);
IUIAutomationElement child = (IUIAutomationElement)rootNode.PlatformObject;
if (child != null)
{
try
{
child = walker.GetFirstChildElement(child);
}
catch (Exception ex)
{
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
while (child != null)
{
// Create child without populating basic property. it will be set all at once in parallel.
var childNode = new DesktopElement(child, true, false)
{
UniqueId = childId++
};
rootNode.Children.Add(childNode);
childNode.Parent = rootNode;
childNode.TreeWalkerMode = this.WalkerMode;
this.Elements.Add(childNode);
try
{
child = walker.GetNextSiblingElement(child);
}
catch (Exception ex)
{
child = null;
System.Diagnostics.Trace.WriteLine("Tree walker exception: " + ex);
}
}
}
Marshal.ReleaseComObject(walker);
}