Unable to cast lists with Reflection in C#
- by DrLazer
I am having a lot of trouble with Reflection in C# at the moment. The app I am writing allows the user to modify the attributes of certain objects using a config file. I want to be able to save the object model (users project) to XML. The function below is called in the middle of a foreach loop, looping through a list of objects that contain all the other objects in the project within them. The idea is, that it works recursively to translate the object model into XML.
Dont worry about the call to "Unreal" that just modifes the name of the objects slightly if they contain certain words.
private void ReflectToXML(object anObject, XmlElement parentElement)
{
Type aType = anObject.GetType();
XmlElement anXmlElement = m_xml.CreateElement(Unreal(aType.Name));
parentElement.AppendChild(anXmlElement);
PropertyInfo[] pinfos = aType.GetProperties();
//loop through this objects public attributes
foreach (PropertyInfo aInfo in pinfos)
{
//if the attribute is a list
Type propertyType = aInfo.PropertyType;
if ((propertyType.IsGenericType)&&(propertyType.GetGenericTypeDefinition() == typeof(List<>)))
{
List<object> listObjects = (aInfo.GetValue(anObject,null) as List<object>);
foreach (object aListObject in listObjects)
{
ReflectToXML(aListObject, anXmlElement);
}
}
//attribute is not a list
else
anXmlElement.SetAttribute(aInfo.Name, "");
}
}
If an object attributes are just strings then it should be writing them out as string attributes in the XML. If an objects attributes are lists, then it should recursively call "ReflectToXML" passing itself in as a parameter, thereby creating the nested structure I require that nicely reflect the object model in memory.
The problem I have is with the line
List<object> listObjects = (aInfo.GetValue(anObject,null) as List<object>);
The cast doesn't work and it just returns null.
While debugging I changed the line to
object temp = aInfo.GetValue(anObject,null);
slapped a breakpoint on it to see what "GetValue" was returning. It returns a "Generic list of objects" Surely I should be able to cast that? The annoying thing is that temp becomes a generic list of objects but because i declared temp as a singular object, I can't loop through it because it has no Enumerator.
How can I loop through a list of objects when I only have it as a propertyInfo of a class?
I know at this point I will only be saving a list of empty strings out anyway, but thats fine. I would be happy to see the structure save out for now.
Thanks in advance
