Getting All Controllers and Actions names in C#

Question

Is it possible to list the names of all controllers and their actions programmatically?

I want to implement database driven security for each controller and action.

Answer 1

If it may helps anyone, I improved @AVH's answer to get more informations using recursivity.
My goal was to create an autogenerated API help page :

 Assembly.GetAssembly(typeof(MyBaseApiController)).GetTypes()
        .Where(type => type.IsSubclassOf(typeof(MyBaseApiController)))
        .SelectMany(type => type.GetMethods(BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.Public))
        .Where(m => !m.GetCustomAttributes(typeof(System.Runtime.CompilerServices.CompilerGeneratedAttribute), true).Any())
        .Select(x => new ApiHelpEndpointViewModel
        {
            Endpoint = x.DeclaringType.Name.Replace("Controller", String.Empty),
            Controller = x.DeclaringType.Name,
            Action = x.Name,
            DisplayableName = x.GetCustomAttributes().FirstOrDefault()?.Name ?? x.Name,
            Description = x.GetCustomAttributes().FirstOrDefault()?.Description ?? String.Empty,
            Properties = x.ReturnType.GenericTypeArguments.FirstOrDefault()?.GetProperties(),
            PropertyDescription = x.ReturnType.GenericTypeArguments.FirstOrDefault()?.GetProperties()
                                        .Select(q => q.CustomAttributes.SingleOrDefault(a => a.AttributeType.Name == "DescriptionAttribute")?.ConstructorArguments ?? new List() )
                                        .ToList()
        })
        .OrderBy(x => x.Controller)
        .ThenBy(x => x.Action)
        .ToList()
        .ForEach(x => apiHelpViewModel.Endpoints.Add(x)); //See comment below

(Just change the last ForEach() clause as my model was encapsulated inside another model).
The corresponding ApiHelpViewModel is :

public class ApiHelpEndpointViewModel
{
    public string Endpoint { get; set; }
    public string Controller { get; set; }
    public string Action { get; set; }
    public string DisplayableName { get; set; }
    public string Description { get; set; }
    public string EndpointRoute => $"/api/{Endpoint}";
    public PropertyInfo[] Properties { get; set; }
    public List> PropertyDescription { get; set; }
}

As my endpoints return IQueryable, the last property (PropertyDescription) contains a lot of metadatas related to CustomType's properties. So you can get the name, type, description (added with a [Description] annotation) etc... of every CustomType's properties.

It goes further that the original question, but if it can help someone...

---

UPDATE

To go even further, if you want to add some [DataAnnotation] on fields you can't modify (because they've been generated by a Template for example), you can create a MetadataAttributes class :

[MetadataType(typeof(MetadataAttributesMyClass))]
public partial class MyClass
{
}

public class MetadataAttributesMyClass
{
    [Description("My custom description")]
    public int Id {get; set;}

    //all your generated fields with [Description] or other data annotation
}

BE CAREFUL : MyClass MUST be :

• A partial class,
• In the same namespace as the generated MyClass

Then, update the code which retrieves the metadatas :

Assembly.GetAssembly(typeof(MyBaseController)).GetTypes()
        .Where(type => type.IsSubclassOf(typeof(MyBaseController)))
        .SelectMany(type => type.GetMethods(BindingFlags.Instance | BindingFlags.DeclaredOnly | BindingFlags.Public))
        .Where(m => !m.GetCustomAttributes(typeof(System.Runtime.CompilerServices.CompilerGeneratedAttribute), true).Any())
        .Select(x =>
        {
            var type = x.ReturnType.GenericTypeArguments.FirstOrDefault();
            var metadataType = type.GetCustomAttributes(typeof(MetadataTypeAttribute), true)
                .OfType().FirstOrDefault();
            var metaData = (metadataType != null)
                ? ModelMetadataProviders.Current.GetMetadataForType(null, metadataType.MetadataClassType)
                : ModelMetadataProviders.Current.GetMetadataForType(null, type);

            return new ApiHelpEndpoint
            {
                Endpoint = x.DeclaringType.Name.Replace("Controller", String.Empty),
                Controller = x.DeclaringType.Name,
                Action = x.Name,
                DisplayableName = x.GetCustomAttributes().FirstOrDefault()?.Name ?? x.Name,
                Description = x.GetCustomAttributes().FirstOrDefault()?.Description ?? String.Empty,
                Properties = x.ReturnType.GenericTypeArguments.FirstOrDefault()?.GetProperties(),
                PropertyDescription = metaData.Properties.Select(e =>
                {
                    var m = metaData.ModelType.GetProperty(e.PropertyName)
                        .GetCustomAttributes(typeof(DescriptionAttribute), true)
                        .FirstOrDefault();
                    return m != null ? ((DescriptionAttribute)m).Description : string.Empty;
                }).ToList()
            };
        })
        .OrderBy(x => x.Controller)
        .ThenBy(x => x.Action)
        .ToList()
        .ForEach(x => api2HelpViewModel.Endpoints.Add(x));

(Credit to this answer)

and update PropertyDescription as public List PropertyDescription { get; set; }