/// <summary>
/// Edits the value of the specified object using the editor style indicated by <seealso cref="UITypeEditor.GetEditStyle(ITypeDescriptorContext)"/>.
/// </summary>
/// <param name="context">An <see cref="ITypeDescriptorContext"/> that can be used to gain additional context information. </param>
/// <param name="provider">An <see cref="IServiceProvider"/> that this editor can use to obtain services.</param>
/// <param name="value">The object to edit.</param>
/// <returns>The new value of the object.</returns>
public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
{
if (null == context)
{
return(null);
}
if (null == provider)
{
return(null);
}
IWindowsFormsEditorService service = (IWindowsFormsEditorService)provider.GetService(typeof(IWindowsFormsEditorService));
if (service != null)
{
ReferenceTypeAttribute refTypeAttribute = GetReferenceType(context);
ConfigurationNode currentNode = (ConfigurationNode)context.Instance;
ConfigurationApplicationNode appNode = GetApplicationNode(currentNode);
ConfigurationNode contextNode = (refTypeAttribute.LocalOnly) ? currentNode : appNode;
ReferenceEditorUI control = new ReferenceEditorUI(contextNode, refTypeAttribute.ReferenceType, (ConfigurationNode)value, service, IsRequired(context));
service.DropDownControl(control);
if (control.SelectedNode != null)
{
Type propertyType = context.PropertyDescriptor.PropertyType;
Type selectedNodeType = control.SelectedNode.GetType();
if (propertyType == selectedNodeType || selectedNodeType.IsSubclassOf(propertyType))
{
return(control.SelectedNode);
}
}
}
return(null);
}
private static ReferenceTypeAttribute GetReferenceType(ITypeDescriptorContext context)
{
foreach (Attribute attribute in context.PropertyDescriptor.Attributes)
{
ReferenceTypeAttribute refAttribute = attribute as ReferenceTypeAttribute;
if (null != refAttribute)
{
return(refAttribute);
}
}
throw new InvalidOperationException(Resources.ExceptionNoRefTypeAttribute);
}