private static void RegisterStandalonePropertyGetter(AutomationProperty automationProperty)
{
// With WPF Automation peers, retrieving UIA property value goes through these steps:
// 1. UIA request comes at ElementProxy which linked with AutomationPeer and wraps it from multithreading, COM etc
// 2. ElementProxy passes request to UI thread and directs it to AutomationPeer.GetPropertyValue(int propertyId)
// 3. AutomationPeer consults its hashtable of getters and tries to find there getter for required property. These
// getters are basically Func<AutomationPeer, object>
// 4. If getter is found - it is called like getter(this) from AutomationPeer, otherwise null returned
//
// Similarly to RegisterPattern() method, we need to add new item to
// private static Hashtable AutomationPeer.s_propertyInfo, in order to let 3rd step from above pass correctly
// Like this line
// AutomationPeer.s_propertyInfo[property.PropertyId] = new AutomationPeer.GetProperty(getter);
// where GetProperty defined in AutomationPeer as:
// private delegate object GetProperty(AutomationPeer peer);
//
// Our getter will try to cast AutomationPeer to IStandalonePropertyProvider and if successful - get result from it.
// Otherwise returns null.
var automationPeerType = typeof(AutomationPeer);
var propertyInfoHashtableField = automationPeerType.GetField("s_propertyInfo", BindingFlags.NonPublic | BindingFlags.Static);
var getterDelegateType = automationPeerType.GetNestedType("GetProperty", BindingFlags.NonPublic);
var getterObject = new StandalonePropertyGetter(automationProperty);
var getterMethodInfo = ReflectionUtils.GetMethodInfo(() => getterObject.Getter(null));
var getter = Delegate.CreateDelegate(getterDelegateType, getterObject, getterMethodInfo);
using (Dispatcher.CurrentDispatcher.DisableProcessing())
{
var propertyHashtable = (Hashtable)propertyInfoHashtableField.GetValue(null);
propertyHashtable[automationProperty.Id] = getter;
}
}
private static void RegisterStandalonePropertyGetter(AutomationProperty automationProperty)
{
// With WPF Automation peers, retrieving UIA property value goes through these steps:
// 1. UIA request comes at ElementProxy which linked with AutomationPeer and wraps it from multithreading, COM etc
// 2. ElementProxy passes request to UI thread and directs it to AutomationPeer.GetPropertyValue(int propertyId)
// 3. AutomationPeer consults its hashtable of getters and tries to find there getter for required property. These
// getters are basically Func<AutomationPeer, object>
// 4. If getter is found - it is called like getter(this) from AutomationPeer, otherwise null returned
//
// Similarly to RegisterPattern() method, we need to add new item to
// private static Hashtable AutomationPeer.s_propertyInfo, in order to let 3rd step from above pass correctly
// Like this line
// AutomationPeer.s_propertyInfo[property.PropertyId] = new AutomationPeer.GetProperty(getter);
// where GetProperty defined in AutomationPeer as:
// private delegate object GetProperty(AutomationPeer peer);
//
// Our getter will try to cast AutomationPeer to IStandalonePropertyProvider and if successful - get result from it.
// Otherwise returns null.
var automationPeerType = typeof(AutomationPeer);
var propertyInfoHashtableField = automationPeerType.GetField("s_propertyInfo", BindingFlags.NonPublic | BindingFlags.Static);
var getterDelegateType = automationPeerType.GetNestedType("GetProperty", BindingFlags.NonPublic);
var getterObject = new StandalonePropertyGetter(automationProperty);
var getterMethodInfo = ReflectionUtils.GetMethodInfo(() => getterObject.Getter(null));
var getter = Delegate.CreateDelegate(getterDelegateType, getterObject, getterMethodInfo);
using (Dispatcher.CurrentDispatcher.DisableProcessing())
{
var propertyHashtable = (Hashtable)propertyInfoHashtableField.GetValue(null);
propertyHashtable[automationProperty.Id] = getter;
}
}