How does the ASP.NET MVC's ViewBag work? MSDN says it is just an Object, which intrigues me, how does "Magic" properties such as ViewBag.Foo and magic strings ViewBag["Hello"] actually work?
Also, how can I make one and use it in my ASP.NET WebForms app?
Examples would be really appreciated!
This question is related to
asp.net
asp.net-mvc
viewbag
ViewBag is of type dynamic but, is internally an System.Dynamic.ExpandoObject()
It is declared like this:
dynamic ViewBag = new System.Dynamic.ExpandoObject();
which is why you can do :
ViewBag.Foo = "Bar";
A Sample Expander Object Code:
public class ExpanderObject : DynamicObject, IDynamicMetaObjectProvider
{
public Dictionary<string, object> objectDictionary;
public ExpanderObject()
{
objectDictionary = new Dictionary<string, object>();
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
object val;
if (objectDictionary.TryGetValue(binder.Name, out val))
{
result = val;
return true;
}
result = null;
return false;
}
public override bool TrySetMember(SetMemberBinder binder, object value)
{
try
{
objectDictionary[binder.Name] = value;
return true;
}
catch (Exception ex)
{
return false;
}
}
}