I want a dynamic static field
I've got a class A with a开发者_StackOverflow社区 public field b
class A
{
public static string b;
}
but now I want to make b dynamic
so I call it anything. So I can make the class a DynamicObject
class A : DynamicObject
{
}
but I the compiler doesn't let me now call A.dynamicThing
cos I have to instantiate A as dynamic.
How can I mangle c# further to make this work?
I don't belive you're going to find a way to make this work. It's not just the DynamicObject that makes things work. The declaration as a variable of the "dynamic" data type is what tells the compiler to actually use the DynamicObject base to resolve the member access. With static access direct to the class, you don't have that. So I really just don't think this is going to work in C# unless that changes in the future.
It's not possible right now with .NET 4
more information in this article.
I think I understand now - the closest you can get is by using an ExpandoObject
:
dynamic foo = new ExpandoObject();
foo.somethinghere = "bar";
foo.dynamicThing = "baz";
Edit:
I don't think its possible to re-route the access to a static property of a class to an expando object if the name of the property does not match - how would the compiler know that that's what you meant to do? You are getting a compile time error after all, not a runtime error.
From MSDN:
When a field, method, property, event, operator, or constructor declaration includes a static modifier, it declares a static member. In addition, a constant or type declaration implicitly declares a static member. Static members have the following characteristics:
When a static member M is referenced in a member-access (Section 7.5.4)
of the form E.M, E must denote a type containing M.
...
public class FakeDynamicMethodInvoker : DynamicObject
{
// your code here
}
public class FakeDynamicWrapper<T>
{
static FakeDynamicWrapper()
{
DynamicStaticField = (dynamic)new FakeDynamicMethodInvoker();
}
public static T DynamicStaticField{ get; set; }
}
public class RealClassWithDynamicStaticField: FakeDynamicWrapper<dynamic>
{
}
somewhere in a code:
RealClassWithDynamicStaticField.DynamicStaticField.AnyMethod();
C# doesn't let you really rename variables to some dynamic name at runtime. Your question is mangled.
If you are wanting variable b to have a dynamic object at runtime, then use the dynamic keyword.
Example:
dynamic b = GetBValue();
b.SomeOperation(); // the type of "b" will be evaluated/chosen at runtime.
Old question but worth to answer :)
Static constructors are the answer to these problems.
https://msdn.microsoft.com/en-us/library/k9x6w0hc.aspx
public class MyClass
{
public static dynamic StaticDynamicObject;
static MyClass()
{
StaticDynamicObject = new ExpandoObject();
StaticDynamicObject.Prop = "woohoo!";
}
}
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