Question

I am trying to update public parameters of a known type MyClass from a NameValueCollection (see code below). This is possible in MVC3, the Controller class has an UpdateModel method which does exactly this with the Request.Params. I would like to do this outside of the Controller though.

Any thoughts?

public class MyClass
{
    public string MyParam { get; set; }
}

…

var values = new NameValueCollection() { { "MyParam", "any string value for my param" } };
var myInstance = new MyClass();
Update(myInstance, values);

Cheers,
T

Answer 1

You should use reflection to perform this task:

This code is provided without proper validation, and it should be put into a method.

var type = myInstance.GetType();
foreach(var keyValue in values)
{
   type.InvokeMember(keyValue.Key,BindingFlags.SetProperty,null,myInstance,  new object[]{keyValue.Value});    

}

There could be an error in this code, but even if it’s the case, the general idea is here.
2 remarks: This code will fail miserably if the property doesn’t exist on MyClass, or if the property type cannot be assigned from a string. It would therefore require proper validation (I know, I am repeating myself ).

You could use expression tree to perform the job too, particularly if you are setting a lot of values on the same known type, as expression trees can be compiled.