extension methods nested within a class

Question

i wanted to know as i start to make some dramatic move from using regular helpers to more and more extension methods so they start to pile up ,

say my top main namespace is as follows :

the main namespace name is myname + last digit of year and current month

thats how i keep it organized as a helper namespace

namespace "myname212" 
{
    namespace DbRelated
    {
        some clasess & methods 
    }

    namespace styling
    {
        same as usual ..
    }

    // .... some more categories and...then

    //the extentions namespace

    namespace CustomExtentions
    {
        // simplest ext class and its first method 
        public static class ToNumber
        {
            public static int Toint(this Textbox TbxToConvrt)
            {
                return Convert.ToInt32(TbxToConvrt.Text);
            }
            //some more of same subject 
        }
    }
}

but what if i have a more general catefory that has it own sub category logocally

namespace Extentions
{
    public static class MainCategory
    {
         public static class SubCat1 
         {
             public static some_method();
         }
         public static class SubCat2 
         {
             public static some_method();
         }
    }  
}

the a hierarchical stracture above will not work .

so is it true that if i'd like to build more categories i could only do it via

nested namespaces instead of nested classes ?

is this what you do ?

Answer 1

You can nest namespaces instead:

namespace My.Nested.Namespace.So.Far
{
    public static class BlaExtensions
    {
    }
}

or even:

namespace My.Nested.Namespace
{
    public static class FooExtensions
    {
    }

    namespace So.Far
    {
        public static class BlaExtensions
        {
        }
    }
}

should work too.