How do I make objects move with the moving platform?

I’m very new to Unity and trying to make a 2d platforming game where you solve puzzles using crates and moving platforms. I have made a platform that moves, however when the player or any object with a rigidbody is on the platform it won’t move with it and just stays in place.

This is my code for the moving platform:

using UnityEngine;
using System.Collections;

public class PlatformMovement : MonoBehaviour {

    public bool activated;

    public GameObject player;

    private Vector3 posA;
    private Vector3 posB;
    private Vector3 nextPos;

    [SerializeField]
    private float speed;

    [SerializeField]
    private Transform childTransform; 

    [SerializeField]
    private Transform transformB;    



    // Use this for initialization
    void Start () {

        posA = childTransform.localPosition;
        posB = transformB.localPosition;
        nextPos = posB;


	}
	



	// Update is called once per frame
	void Update () {

        Move();
        

	}


    public void OnTriggerStay2D(Collider2D other)
    {

        Transform thingOnPlatform = other.transform;
        thingOnPlatform.position = Vector3.MoveTowards(thingOnPlatform.position, nextPos, (speed * Time.deltaTime));

    }


    private void Move()
    {
        childTransform.localPosition = Vector3.MoveTowards(childTransform.localPosition, nextPos, speed * Time.deltaTime); 

        if (Vector3.Distance(childTransform.localPosition,nextPos) <= 0.1) 
        {
            ChangeDir();
        }
    }

    private void ChangeDir()
    {
        nextPos = nextPos != posA ? posA : posB; 

    }
}

I’m using Unity 5.4.0f3 if you need to know.

Hi! Right now you are directly setting the transform’s localPosition. I’m not sure if it will solve the problem in your case, but you might instead consider using Rigidbody2D.SetPosition (). (Likewise, make sure your moving platform has a Rigidbody2D component with the isKinematic flag to set to true.)