How to convert a list into Json?Code not working

Unity Engine
1

I was trying to convert a list into json format.The jsonstring I am getting is always empty.Code below

[System.Serializable]
public class ListContainer
{

    public List<PlayerHandler> SaveValues;

    public ListContainer(List<PlayerHandler> _saveVal)
    {
        SaveValues = _saveVal;
    }

}

public class Testing : MonoBehaviour
{
List<PlayerHandler> getAlldata;

var container = new ListContainer(getAlldata);
string jsonstring = JsonUtility.ToJson(container);
//the jsonstring  is always empty

}
2

This question asked million times before. Unity serializer do not support arrays as root object as stated in the manual.

[Serializable]
class Container<T> {
public T[] array;
}
3

From the below code I once got the json string.So what is the difference I am passing the same list in the below code.

public struct ListContainer

{

  public List<DataHandlers> SaveValues;

   /// <summary>

  /// Constructor

  /// </summary>

  /// <param name="_dataList">Data list value</param>

  public ListContainer(List<DataHandlers> _dataList)

    {
  
    SaveValues = _dataList;

    }

}


 SaveValues.Clear();
           
 SaveValues = UnityARHitTestExample.HittestInstance.Modelinfo;

 ListContainer container = new ListContainer(SaveValues);
            
 string jsonstring = JsonUtility.ToJson(container);
            
 Debug.Log("Save JSON String = " + jsonstring);

Where Modelinfo

public List<DataHandlers> Modelinfo = new List<DataHandlers>();


[Serializable]
public class DataHandlers
{
    public int modelid;
    public Vector3 localposinmap;
    public Quaternion localrotinmap;
    public Vector3 sizeofobj;


    public DataHandlers(int idmodel,Vector3 localpos, Quaternion localrot, Vector3 objsize)
    {
        this.modelid = idmodel;
        this.localposinmap = localpos;
        this.localrotinmap = localrot;
        this.sizeofobj = objsize;


    }


}
4

Your first example getAllData is null, I’m not sure what jsonUtility does with that to begin with. Beyond that, I usually use json.net for my json stuff.

5

In both the cases I am using a list.In one I got a json string and in another I dont get it.