如何获取所有属性的列表，包括类文件中嵌套对象中的属性

Question

I have a class with nested properties, similar to the following:

Class X 
{ 
    public ClassA propA { get; set; }  
    public IEnumerable<ClassB> propB { get; set; }
}

where

Class A 
{ 
    public IEnumerable<ClassC> prop C { get; set; } 
    public ClassD propD { get; set; } // Enum type
}

Class B 
{ 
    public ClassE propE { get; set; }  
    public string prop1...prop10 { get; set; } 
    public IEnumerable<ClassF> propF { get; set; }
} // and so on

I am required to develop a generic method which can accept any class file and list out all properties along with their values across all these layers. There can be files with a complexity as shared in this example or more!

I have used Reflection and LINQ queries to figure the names of these properties but can only get this information for up to 2 layers and have not been able to identify properties which could be of another class type and obtain it's corresponding properties as well.

I would want to keep extensive looping / recursion as the last approach but would rather prefer LINQ solutions as irrespective of the complexity, this would have to be processed in under a minute.

I would need a list of objects with all these properties as a response. This is for PII Data cleansing

I seem to have exhausted all options and would love to hear your solutions to this.

Many thanks!

Answer 1

Using some extension methods from my library, and assuming you only need properties and not also fields, you can write a routing to queue work objects and process the queue. This outputs the properties prefixed by their path through the classes, but you could only use the property names at the bottom instead.

public static class ObjectExt {
    public static List<(string, string)> AllPropsWithValues(this object first) {
        var ans = new List<(string, string)>();

        var workQueue = new Queue<(string, object)>();
        workQueue.Enqueue(("", first));

        while (!workQueue.IsEmpty()) {
            var (objName, workObj) = workQueue.Dequeue();
            if (workObj != null) {
                var workType = workObj.GetType();

                if (workType.IsSimple()) {
                    ans.Add((objName, workObj.ToString()));
                }
                else if (workType.IsIEnumerable()) {
                    var index = 0;
                    foreach (var obj in (IEnumerable)workObj) {
                        workQueue.Enqueue(($"{objName}[{index++}]", obj));
                    }
                }
                else {
                    foreach (var pi in workType.GetProperties()) {
                        workQueue.Enqueue(($"{objName.SuffixNonEmpty(".")}{pi.Name}", pi.GetValue(workObj)));
                    }
                }
            }
        }
        return ans;
    }
}

NOTE: If you prefer the output in a different order, you could sort ans eg by returning ans.OrderBy(t => t.Item1).ToList() .

These are the extension methods used:

public static class MyExt {
    public static bool IsEmpty<T>(this Queue<T> q) => q.Count == 0;
    public static bool IsNullableType(this Type aType) =>
    // instantiated generic type only
        aType.IsGenericType &&
        !aType.IsGenericTypeDefinition &&
        Object.ReferenceEquals(aType.GetGenericTypeDefinition(), typeof(Nullable<>));
    // from Stack Overflow
    public static bool IsSimple(this Type type) =>
        type.IsNullableType() ? type.GetGenericArguments()[0].IsSimple()
                              : type.IsPrimitive ||
                                type.IsEnum ||
                                type.Equals(typeof(string)) ||
                                type.Equals(typeof(decimal)) ||
                                type.Equals(typeof(TimeSpan)) ||
                                type.Equals(typeof(DateTime));
    public static bool IsIEnumerable(this Type type) => type.GetInterface(nameof(IEnumerable)) != null;
    public static string SuffixNonEmpty(this string s, string after) => String.IsNullOrEmpty(s) ? String.Empty : $"{s}{after}";

}