Type.GetFields() doesn't find Struct field

Question

I am using the following line from Reflection to get all the fields in my object:

FieldInfo[] l_Fields = GetType().GetFields( BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance );

It works fine for all my fields but ignores this one completely:

private OffSet m_Offest;

'Offset' being a struct made as such:

public struct OffSet
{
  public float x;
  public float y;
}

This field is not in the returned array, is there any way to get it?

Here is the definition of the class. I am getting the fields in the last two functions.

[Serializable]
public abstract class AITreeNode : ISerializable
{
    //>----------------------------------------------------------------------------------------
    // STRUCT
    //-----------------------------------------------------------------------------------------

    public struct OffSet
    {
        public float x;
        public float y;
    }

    //>----------------------------------------------------------------------------------------
    // ENUM
    //-----------------------------------------------------------------------------------------
    public enum Status
    {
        None,
        Available,
        Unavailable,
        Active,
        Success,
        Failed
    }
    //>-----------------------------------------------------------------------------------------
    // VARIABLES
    //------------------------------------------------------------------------------------------
    public      String          Caption;
    public      bool            Enabled                 = true;
    // Display
    private     OffSet          m_Offest;

    // Non Serialized data
    [NonSerialized] protected   AITree          m_AITreeAT;
    [NonSerialized] protected   AITreeBranch    m_BranchATB;
    [NonSerialized] protected   Status          m_LastStatusS = Status.None;
    [NonSerialized] protected   bool            m_IsActiveB;

    //>-----------------------------------------------------------------------------------------
    // GETTERS
    //------------------------------------------------------------------------------------------
    public AITreeBranch     GetBranchATB()      {       return m_BranchATB;     }
    public bool             IsActive()          {       return m_IsActiveB;     }
    public Status           LastStatusS()       {       return m_LastStatusS;     }
    //>-----------------------------------------------------------------------------------------
    // SETTERS
    //------------------------------------------------------------------------------------------
    public void             SetBranch   ( AITreeBranch _BranchATB   )   {   m_BranchATB = _BranchATB;   }
    public void             SetAITree   ( AITree _TreeAT            )   {   m_AITreeAT = _TreeAT;       }
    //>-----------------------------------------------------------------------------------------
    //-----------------------------------------------------------------------------------------
    public float X
    {            get { return m_Offest.x; }             set { m_Offest.x = value; }                 }
    //>-----------------------------------------------------------------------------------------
    public float Y
    {            get { return m_Offest.y; }             set { m_Offest.y = value;  }                }
    //>-----------------------------------------------------------------------------------------

    //>-----------------------------------------------------------------------------------------
    //------------------------------------------------------------------------------------------
    public AITreeNode()
    {
        m_Offest.y = -5;
    }

    #region Serialization
    //>-----------------------------------------------------------------------------------------
    // The special constructor is used to deserialize values.
    // Every class inheriting from AITreeNode needs to implement a constructor with such parameters
    //------------------------------------------------------------------------------------------
    public AITreeNode( SerializationInfo info, StreamingContext context )
    {
        // Reset the property value using the GetValue method.
        FieldInfo[] l_FieldsAFI = GetType().GetFields( BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance );
        foreach ( FieldInfo fieldInfo in l_FieldsAFI )
        {
            if ( fieldInfo.IsNotSerialized ) continue;
            try
            {
                fieldInfo.SetValue( this, info.GetValue( fieldInfo.Name, fieldInfo.FieldType ) );
            }
            catch
            {
                UnityEngine.Debug.Log( "Field " + fieldInfo.Name + " is new. Default value is used" );
            }
        }
    }
    //>-----------------------------------------------------------------------------------------
    // Implement this method to serialize data. The method is called on serialization.
    //------------------------------------------------------------------------------------------
    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {
        // Use the AddValue method to specify serialized values.
        FieldInfo[] l_FieldsAFI = GetType().GetFields( BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance );

        foreach ( FieldInfo fieldInfo in l_FieldsAFI )
        {
            if ( fieldInfo.IsNotSerialized )
            {                    
                UnityEngine.Debug.Log( "Non serialized Field " + fieldInfo.Name );
                continue;
            }
            info.AddValue( fieldInfo.Name, fieldInfo.GetValue( this ), fieldInfo.FieldType );


        UnityEngine.Debug.Log( "Saving Field " + fieldInfo.Name );
            }
        }
... rest of the class
}

Answer 1

As I anticipated, the issue is with inheritance. Private fields are not returned if it was declared in base class. You need to use Type.BaseType to get that info.

Here's how you do it.

var typeHierarchies = new List<Type>();
var type = this.GetType();      
while(type.BaseType != null)
{
    typeHierarchies.Add(type);
    type = type.BaseType;
}
FieldInfo[] l_Fields = typeHierarchies.SelectMany( x=>x.GetFields( BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)).ToArray();

Answer 2

I solved the problem by changing the accessibility of m_Offset from "private" to "protected".

The issue was that I was calling the GetFields() function from a child class and this class couldn't access the private fields of the base.

I didn't go with the BaseType.GetFields() method because I also needed to get the fields of the subclass , not only those of the BaseType.

Thank you for the answers