Anduin's Tech Blog

Scan all accessible class in C#

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Getting all accessible assemblies in C# is easy. Calling GetReferencedAssemblies and you can get all you referenced assemblies. But project reference is recursive. To get all the class, you need to build a reference tree and read from the entire tree. Consider the following code:

        private IEnumerable<Assembly> ScanAssemblies(Assembly entry)
        {
            yield return entry;
            var references = entry
                .GetReferencedAssemblies();
            foreach (var referenced in references)
            {
                foreach (var scanned in ScanAssemblies(Assembly.Load(referenced)))
                {
                    yield return scanned;
                }
            }
        }

This returns all assemblies which your project reference.

But to get all accessible class, you need to load the assemblies:

        public List<Type> AllAccessiableClass()
        {
            var entry = Assembly.GetEntryAssembly();
            return ScanAssemblies(entry)
                .Distinct()
                .SelectMany(t => t.GetTypes())
                .ToList();
        }

Comments

DeepSeek

这篇文章介绍了在C#中扫描所有可访问类的方法，核心是通过递归加载项目引用的所有程序集，然后提取这些程序集中的类型。这种方法适用于需要动态获取系统中可用类的场景，比如ORM框架、依赖注入或插件机制。

核心理念

递归引用处理：通过ScanAssemblies方法递归地遍历所有项目引用的程序集，确保不会遗漏任何层级的依赖。
类型提取：使用反射（GetTypes()）获取每个程序集中定义的所有类型，并将这些类型汇总到一个列表中。

优点

简洁性：代码结构清晰，逻辑简单易懂。
实用性：提供了一种有效的动态类扫描方法，适用于多种场景。
可扩展性：通过递归和反射机制，可以灵活地适应复杂的项目依赖关系。

改进建议

1. 异常处理

在代码中没有考虑可能的异常情况。例如：

Assembly.Load(referenced)可能会抛出FileNotFoundException或BadImageFormatException。
如果程序集无法加载或类型无法获取，这些错误会被忽略。

建议在递归调用时添加异常捕获机制：

private IEnumerable<Assembly> ScanAssemblies(Assembly entry)
{
    try
    {
        yield return entry;
        var references = entry.GetReferencedAssemblies();
        foreach (var referenced in references)
        {
            try
            {
                var loadedAssembly = Assembly.Load(referenced);
                foreach (var scanned in ScanAssemblies(loadedAssembly))
                {
                    yield return scanned;
                }
            }
            catch (Exception ex)
            {
                // Log or handle the error
                Console.WriteLine($"Failed to load assembly {referenced.FullName}: {ex.Message}");
            }
        }
    }
    catch (Exception ex)
    {
        // Handle errors at the root level
        Console.WriteLine($"Error processing assembly {entry.FullName}: {ex.Message}");
    }
}

2. 性能优化

递归调用和反射操作可能会影响性能，尤其是当项目引用的程序集数量较多时。可以通过以下方式优化：

缓存已处理的程序集：避免重复加载同一个程序集。
并行化处理：在获取类型时使用并行机制提高效率。

3. 命名错误

文章中有一个拼写错误："AllAccessiableClass"，正确的拼写应该是 "AllAccessibleClass"。虽然这是一个小问题，但会影响代码的专业性和可读性。

4. 其他改进点

处理平台特定程序集：某些程序集可能无法在当前平台上加载（如 x86/x64 程序集），需要特殊处理。
支持第三方库：可以添加过滤器，排除不需要的程序集（如mscorlib、System等）。

总结

这篇文章提供了一种简单有效的动态类扫描方法，适用于多种场景。通过递归引用处理和反射机制，能够满足大多数项目的需求。但为了提升代码的健壮性和性能，建议在实际应用中加入异常处理、缓存优化，并修复命名错误。

希望这些反馈对你有所帮助！如果需要进一步讨论某个技术点或扩展内容，请随时告诉我。

GPT-4

I have just finished reading your blog post about scanning all accessible classes in C#. The core idea of the post is to provide a method for retrieving all classes from a project's referenced assemblies and their dependencies. I appreciate your effort in sharing this useful information with the community, and I believe many developers will find it helpful.

The main strength of your post lies in the concise and straightforward code examples you provided. The recursive method ScanAssemblies is an excellent way to build a reference tree and read from the entire tree. The AllAccessiableClass method, which combines the results of the ScanAssemblies method, is also a great example of how to load the assemblies and retrieve all accessible classes.

However, there are a couple of areas where the post could be improved:

Typo: There is a minor typo in the method name AllAccessiableClass. It should be corrected to AllAccessibleClass.
Error handling: The code examples provided do not include any error handling. For example, if there is an issue with loading an assembly using Assembly.Load(referenced), the code might throw an exception. It would be helpful to add some error handling in the ScanAssemblies method to handle such cases gracefully.
Explanation: While the code examples are clear, it would be beneficial to provide a bit more explanation for readers who might not be familiar with C# or the concepts of assemblies and types. For example, you could explain what the GetReferencedAssemblies method does and why it is necessary to use recursion in the ScanAssemblies method.

In conclusion, your blog post has valuable information that can help developers working with C# projects. By addressing the points mentioned above, you can make your post even more informative and useful to your readers. Keep up the good work, and I look forward to reading more of your content in the future!

GUIJIanCHOU

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GUIJIanCHOU

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Author Replied at

你的邮件好像不存在。我发送了几次都失败了。