void DelayLocateDataContext(object obj, RoutedEventArgs args)
{
var frameworkElement = TargetObject as FrameworkElement;
if (frameworkElement != null)
{
frameworkElement.Loaded -= DelayLocateDataContext;
object dataContext;
dataContext = BindHelper.LocateValidDependencyPropertyByAllTrees(TargetObject as DependencyObject, FrameworkElement.DataContextProperty, MethodName, PropertyName);
if (dataContext != null)
{
#if !WINDOWS_UWP
if (TargetProperty is DependencyProperty)
{
frameworkElement.SetValue((DependencyProperty)TargetProperty, dataContext);
}
#else
if (TargetProperty as PropertyInfo != null)
{
((PropertyInfo)TargetProperty).SetValue(TargetObject, dataContext);
}
#endif
}
frameworkElement.Loaded -= DelayLocateDataContext;
}
}
/// <summary>
/// Get a source object for binding.
/// If it is not set on, by default the method will search the first defined DataContext property value.
/// </summary>
/// <param name="serviceProvider">Object that can provide services for the markup extension.</param>
/// <returns>Reference to a source object.</returns>
protected override object ObtainSourceObject(IServiceProvider serviceProvider)
{
// For WinRT we provide a valid targets through BindXAML class.
if (Source == null)
{
// ReSharper disable SuggestUseVarKeywordEvident
IProvideValueTarget service = serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
// ReSharper restore SuggestUseVarKeywordEvident
if ((service != null) && (service.TargetObject != null))
{
if (DeepScanAllTrees)
{
return(BindHelper.LocateValidDependencyPropertyByAllTrees(service.TargetObject as DependencyObject, FrameworkElement.DataContextProperty, ExecuteMethodName, ExecutePropertyName));
}
else
{
return(BindHelper.LocateValidDependencyPropertyByAllTrees(service.TargetObject as DependencyObject, FrameworkElement.DataContextProperty));
}
}
}
if (Source is string)
{
}
return(Source);
}
/// <summary>
/// Returns an object that should be set on the property where this extension is applied.
/// </summary>
/// <param name="serviceProvider">Object that can provide services for the markup extension.</param>
/// <returns>The object value to set on the property where the markup extension provided
/// value is evaluated.</returns>
/// <exception cref="System.InvalidOperationException">serviceProvider was null, or failed to
/// implement a required service.</exception>
public override object ProvideValue(IServiceProvider serviceProvider)
{
object obj = null;
Type typeToResolve;
if (_dataContextType == null)
{
typeToResolve = typeof(object);
}
else if (_dataContextType is Type)
{
typeToResolve = (Type)_dataContextType;
}
else if (_dataContextType is String)
{
#if !WINDOWS_UWP
// ReSharper disable SuggestUseVarKeywordEvident
IXamlTypeResolver service = serviceProvider.GetService(typeof(IXamlTypeResolver)) as IXamlTypeResolver;
// ReSharper restore SuggestUseVarKeywordEvident
typeToResolve = BindHelper.ResolveTypeByName((string)_dataContextType);
if ((service != null) && (typeToResolve == null))
{
typeToResolve = service.Resolve((string)_dataContextType);
}
#else
typeToResolve = BindHelper.ResolveTypeByName((string)_dataContextType);
#endif
}
else
{
throw new ArgumentNullException("LocateDataContext - DataContextType can be 'Type' or 'String' or empty.");
}
// ReSharper disable SuggestUseVarKeywordEvident
IProvideValueTarget serviceProvideValueTarget = serviceProvider.GetService(typeof(IProvideValueTarget)) as IProvideValueTarget;
// ReSharper restore SuggestUseVarKeywordEvident
if ((serviceProvideValueTarget != null) && (serviceProvideValueTarget.TargetObject != null))
{
// Save targets for case delayed processing
TargetObject = serviceProvideValueTarget.TargetObject;
TargetProperty = serviceProvideValueTarget.TargetProperty;
if (!(serviceProvideValueTarget.TargetObject is DependencyObject))
{
throw new AggregateException("LocateDataContext - Target of the markup extension must be the DependencyObject type.");
}
obj = BindHelper.LocateValidDependencyPropertyByAllTrees(serviceProvideValueTarget.TargetObject as DependencyObject, FrameworkElement.DataContextProperty, MethodName, PropertyName, null, typeToResolve);
if (obj == null)
{
var frameworkElement = TargetObject as FrameworkElement;
if (frameworkElement != null)
{
frameworkElement.Loaded += DelayLocateDataContext;
}
}
}
return(obj);
}
void LateBiningOfCommandInterface(object obj, RoutedEventArgs args)
#endif
{
object dataContext;
if (DeepScanAllTrees)
{
dataContext = BindHelper.LocateValidDependencyPropertyByAllTrees(TargetObject as DependencyObject, FrameworkElement.DataContextProperty, ExecuteMethodName, ExecutePropertyName);
}
else
{
dataContext = BindHelper.LocateValidDependencyPropertyByAllTrees(TargetObject as DependencyObject, FrameworkElement.DataContextProperty);
}
var frameworkElement = TargetObject as FrameworkElement;
if (frameworkElement == null)
{
return;
}
// Remove handler back
#if !WINDOWS_UWP
DependencyPropertyDescriptor dppDescr = DependencyPropertyDescriptor.FromProperty(FrameworkElement.DataContextProperty, FrameworkElement.DataContextProperty.OwnerType);
dppDescr.RemoveValueChanged(frameworkElement, LateBiningOfCommandInterface);
#else
frameworkElement.Loaded -= LateBiningOfCommandInterface;
#endif
if (dataContext != null)
{
var replaceCommand = ResolvePropertyValues(dataContext);
#if !WINDOWS_UWP
if (TargetProperty is DependencyProperty)
{
frameworkElement.SetValue((DependencyProperty)TargetProperty, replaceCommand);
}
#else
if (TargetProperty as PropertyInfo != null)
{
((PropertyInfo)TargetProperty).SetValue(TargetObject, replaceCommand);
}
#endif
}
}
/// <summary>
/// Represents the proxy method that will handle various routed events that do not
/// have specific event data beyond the data that is common for all routed events.
/// </summary>
/// <param name="sender">The object which is the originator of the event.</param>
/// <param name="e">The event data.</param>
public void RoutedEventHandlerProxy(object sender, T e)
{
if ((_handler == null) && (!_errorInHandlerSetup))
{
// Try to get a proper handler
var element = sender as DependencyObject;
if (element != null)
{
var sourceBaseProvided = BindHelper.LocateValidDependencyPropertyByAllTrees(element, FrameworkElement.DataContextProperty, _methodName, _propertyName);
if (sourceBaseProvided != null)
{
try
{
if (!string.IsNullOrEmpty(_methodName))
{
_handler = (ProxyEventHandler)BindHelper.EventHandlerDelegateFromMethod(_methodName, sourceBaseProvided, typeof(ProxyEventHandler));
}
if (!string.IsNullOrEmpty(_propertyName))
{
_handler = (ProxyEventHandler)BindHelper.EventHandlerDelegateFromProperty(_propertyName, sourceBaseProvided, typeof(ProxyEventHandler));
}
}
#if DEBUG
catch (Exception ex)
{
// Should cause an exception if binding was not resolved.
Debug.WriteLine($"Cannot create delegate: {_methodName}|{_propertyName} for {sourceBaseProvided} Exception: {ex.Message}");
#else
catch
{
#endif
_errorInHandlerSetup = true;
}
}
}
}
if (_handler != null)
{
_handler(sender, e);
}
}
