Visual Studio: How to group partial class files in Solution Explorer

Partial class allows you to split the definition of a class or a struct, an interface or a method over two or more source files

When working on large projects, spreading a class over separate files enables multiple programmers to work on it at the same time.

Use the partial keyword modifier, as shown here

public partial class Student
{
    public void DoHomeWork()
    {
    }
}

public partial class Student
{
    public Student GetStudentInfo(string id)
    {
    }
}

You can create Customer, CustomerBase class and ICustomer interface, then you can use the File Nesting tool to group all classes

namespace NestFiles
{
    public partial class Customer : CustomerBase
    {
    }
}
namespace NestFiles
{
    public abstract partial class CustomerBase : ICustomer
    {
    }
}
namespace NestFiles
{
    public interface ICustomer
    {
    }
}

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