如何用C#反射筛选指定命名空间中的顶级类（排除被引用类）

Here's a practical, reflection-based approach to filter out classes that are used as property types by other classes in your target namespace:

Step-by-Step Breakdown #

1. Grab all classes in your target namespace: First, we pull every class defined in ConsoleApp1.Methods.
2. Track classes used as property types: Iterate through each class's properties, collecting any type that’s a class in the same namespace (these are the "dependent" classes).
3. Filter for top-level classes: Exclude any class that appears in the tracked property types list—what’s left are your standalone top-level classes.

Complete Code Example #

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

public class TopLevelClassFinder
{
    public List<Type> GetTopLevelClassesInNamespace()
    {
        // Use Assembly.Load("YourAssemblyName") if classes are in a different assembly
        var assembly = Assembly.GetExecutingAssembly();
        const string targetNamespace = "ConsoleApp1.Methods";

        // Get all classes in the target namespace
        var allNamespaceClasses = assembly.GetTypes()
            .Where(t => t.Namespace == targetNamespace && t.IsClass)
            .ToList();

        // Collect all classes referenced as property types
        var usedAsPropertyTypes = new HashSet<Type>();
        foreach (var cls in allNamespaceClasses)
        {
            // Adjust BindingFlags here if you need to include non-public/static properties
            var properties = cls.GetProperties(BindingFlags.Public | BindingFlags.Instance);
            foreach (var prop in properties)
            {
                var propType = prop.PropertyType;
                // Check if the property type is a class in our target namespace
                if (propType.Namespace == targetNamespace && propType.IsClass)
                {
                    usedAsPropertyTypes.Add(propType);
                }
            }
        }

        // Filter out dependent classes to get only top-level ones
        var topLevelClasses = allNamespaceClasses
            .Where(cls => !usedAsPropertyTypes.Contains(cls))
            .ToList();

        return topLevelClasses;
    }
}

Quick Notes #

• Binding Flags: If your classes use non-public properties to reference other namespace classes, update the BindingFlags (e.g., add BindingFlags.NonPublic) to include those.
• Generic Types: If you have generic property types like List<Method100Response201_1>, this code won’t catch the generic argument. To handle that, add logic to check propType.GetGenericArguments() and add those types to the usedAsPropertyTypes set.
• Assembly Loading: If your classes live in a separate assembly, replace GetExecutingAssembly() with Assembly.Load("YourAssemblyName").

When you run this with your example classes, it will return exactly the top-level classes you expect: Method100Response201, Method100Response404, Method200Response200.

内容的提问来源于stack exchange，提问作者Nick