protected override void Dispose(bool disposing)
{
if (Pattern != null)
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(Pattern);
this.Pattern = null;
}
base.Dispose(disposing);
}
public ValuePattern(A11yElement e, IUIAutomationValuePattern p) : base(e, PatternType.UIA_ValuePatternId)
{
Pattern = p;
PopulateProperties();
}
private ValuePattern(IUIAutomationValuePattern pattern)
{
_pattern = pattern;
}
// Step 2: Find all the links of interest on the loaded page.
private void buttonFindLinks_Click(object sender, EventArgs e)
{
checkedListBoxLinks.Items.Clear();
if (webBrowserPage.Url == null)
{
MessageBox.Show(this,
"Please load the web page of interest.",
"Link Getter",
MessageBoxButtons.OK);
labelLinkCount.Text = "No links found.";
return;
}
// Get the UIA element for the webBrowser with the page of interest loaded.
IUIAutomationElement elementBrowser =
automation.ElementFromHandle(webBrowserPage.Handle);
// Build up a cache request for all the data we need, to reduce the time it
// takes to access the link data once with have the collection of links.
IUIAutomationCacheRequest cacheRequest = automation.CreateCacheRequest();
cacheRequest.AddProperty(propertyIdName);
cacheRequest.AddPattern(patternIdValue);
cacheRequest.AddProperty(propertyIdValueValue);
// Assume the links have names as expected, and we don't need to
// search children of the links for names.
cacheRequest.TreeScope = TreeScope.TreeScope_Element;
// We want the collection of all links on the page.
IUIAutomationCondition conditionControlView = automation.ControlViewCondition;
IUIAutomationCondition conditionHyperlink =
automation.CreatePropertyCondition(
propertyIdControlType, controlTypeIdHyperlink);
IUIAutomationCondition finalCondition = automation.CreateAndCondition(
conditionControlView, conditionHyperlink);
// TODO: Call FindAllBuildCache() in a background thread in case it takes
// a while. As it is, the app UI's going to freeze.
// Now get the collection of links.
IUIAutomationElementArray elementArray = elementBrowser.FindAllBuildCache(
TreeScope.TreeScope_Descendants, finalCondition, cacheRequest);
if (elementArray != null)
{
// Process each returned hyperlink element.
for (int idxLink = 0; idxLink < elementArray.Length; ++idxLink)
{
IUIAutomationElement elementLink = elementArray.GetElement(idxLink);
// Despite the fact that we've got the names of the UIA links, don't
// use that information here. Perhaps we will use it in the future.
IUIAutomationValuePattern valuePattern =
(IUIAutomationValuePattern)elementLink.GetCurrentPattern(
patternIdValue);
if (valuePattern != null)
{
// We're only interested in references the page makes to itself.
string strValueLink = valuePattern.CachedValue;
var index = strValueLink.IndexOf('#');
if ((index > 0) && strValueLink.StartsWith(textBoxURL.Text))
{
checkedListBoxLinks.Items.Add(new LinkItem()
{
linkName = elementLink.CachedName,
linkURL = strValueLink
});
}
}
}
}
// Let's assume we'll want most of the links found.
SetLinkCheckedState(true);
labelLinkCount.Text = "Count of links found: " +
checkedListBoxLinks.Items.Count;
}
private ValuePattern(IUIAutomationValuePattern pattern)
{
_pattern = pattern;
}
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// GetCurrentDataFromElement()
//
// Get the current name from a UIA element, (incurring the time cost of various a cross-proc calls).
// If the element doesn't have a name, optionally try to find a name from the children of the element
// by using a TreeWalker.
//
// Runs on the background thread.
//
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
private string GetCurrentDataFromElement(IUIAutomationElement element, bool fSearchLinkChildren)
{
string strName = null;
// Call back to the target app to retrieve the bounds of the hyperlink element.
tagRECT rectBounds = element.CurrentBoundingRectangle;
// If we're the hyperlink has a zero-size bounding rect, ignore the element.
if ((rectBounds.right > rectBounds.left) && (rectBounds.bottom > rectBounds.top))
{
// Get the name of the element, (again incurring a cross-proc call). This name will often
// be the text shown on the screen.
string strNameFound = element.CurrentName;
if ((strNameFound != null) && (strNameFound.Length > 0))
{
// We have a usable name.
strName = strNameFound;
}
else
{
// The hyperlink has no usable name. Consider using the name of a child element of the hyperlink.
if (fSearchLinkChildren)
{
// Use a Tree Walker here to try to find a child element of the hyperlink
// that has a name. Tree walking is a time consuming action, so would be
// avoided by a shipping app if alternatives like FindFirst, FindAll, or
// BuildUpdatedCache could get the required data.
IUIAutomationTreeWalker controlWalker = _automation.ControlViewWalker;
IUIAutomationElement elementChild = controlWalker.GetFirstChildElement(element);
while (elementChild != null)
{
string strNameChild = elementChild.CurrentName;
if ((strNameChild != null) && (strNameChild.Length > 0))
{
// Use the name of this child element.
strName = strNameChild;
break;
}
// Continue to the next child element.
elementChild = controlWalker.GetNextSiblingElement(elementChild);
}
}
}
}
// While this sample doesn't use the destination of the hyperlink, if it wanted
// to get the destination, that might be available as the Value property of the
// element. The Value property is part of the Value pattern, and so is accessed
// through the Value pattern.
// Check first whether the element supports the Value pattern.
IUIAutomationValuePattern valuePattern = (IUIAutomationValuePattern)element.GetCurrentPattern(_patternIdValue);
if (valuePattern != null)
{
string strValue = valuePattern.CurrentValue;
// This is where the destination of the link would be used...
}
return(strName);
}
internal static ValuePattern Wrap(
AutomationElement element,
IUIAutomationValuePattern valuePattern)
{
return(new ValuePattern(element: element, valuePattern: valuePattern));
}
ValuePattern(AutomationElement element, IUIAutomationValuePattern valuePattern)
: base(el: element)
{
this._valuePattern = valuePattern;
}
private ValuePattern(AutomationElement el, IUIAutomationValuePattern pattern, bool cached)
: base(el, cached)
{
Debug.Assert(pattern != null);
this._pattern = pattern;
}
