Is there a way to create a delegate to get and set values for a FieldInfo?

Question

For properties there are GetGetMethod and GetSetMethod so that I can do:

Getter = (Func)Delegate.CreateDelegate(typeof(         


        

Answer 1

Here is an another option for creating a delegate when you are working with objects (don't know specific type of a field). Though it is slower if field is a structure (because of boxing).

public static class ReflectionUtility
{
    public static Func CompileGetter(this FieldInfo field)
    {
        string methodName = field.ReflectedType.FullName + ".get_" + field.Name;
        DynamicMethod setterMethod = new DynamicMethod(methodName, typeof(object), new[] { typeof(object) }, true);
        ILGenerator gen = setterMethod.GetILGenerator();
        if (field.IsStatic)
        {
            gen.Emit(OpCodes.Ldsfld, field);
            gen.Emit(field.FieldType.IsClass ? OpCodes.Castclass : OpCodes.Box, field.FieldType);
        }
        else
        {
            gen.Emit(OpCodes.Ldarg_0);
            gen.Emit(OpCodes.Castclass, field.DeclaringType);
            gen.Emit(OpCodes.Ldfld, field);
            gen.Emit(field.FieldType.IsClass ? OpCodes.Castclass : OpCodes.Box, field.FieldType);
        }
        gen.Emit(OpCodes.Ret);
        return (Func)setterMethod.CreateDelegate(typeof(Func));
    }

    public static Action CompileSetter(this FieldInfo field)
    {
        string methodName = field.ReflectedType.FullName + ".set_" + field.Name;
        DynamicMethod setterMethod = new DynamicMethod(methodName, null, new[] { typeof(object), typeof(object) }, true);
        ILGenerator gen = setterMethod.GetILGenerator();
        if (field.IsStatic)
        {
            gen.Emit(OpCodes.Ldarg_1);
            gen.Emit(field.FieldType.IsClass ? OpCodes.Castclass : OpCodes.Unbox_Any, field.FieldType);
            gen.Emit(OpCodes.Stsfld, field);
        }
        else
        {
            gen.Emit(OpCodes.Ldarg_0);
            gen.Emit(OpCodes.Castclass, field.DeclaringType);
            gen.Emit(OpCodes.Ldarg_1);
            gen.Emit(field.FieldType.IsClass ? OpCodes.Castclass : OpCodes.Unbox_Any, field.FieldType);
            gen.Emit(OpCodes.Stfld, field);
        }
        gen.Emit(OpCodes.Ret);
        return (Action)setterMethod.CreateDelegate(typeof(Action));
    }
}