Property Help

Unity Engine
1

Hello,
Im taking a stab at setting up my first c# property but having some trouble.

Assets/Scripts/NodeScript/NodeTile.cs(26,18): error CS0201: Only assignment, call, increment, decrement, await, and new object expressions can be used as a statement

Could someone please educate on what Im going wrong here. Thanks in advance

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


[System.Serializable]
public class NodeTile : NodeBase {


    private NodeAttrActivePrefab _nodeAttrActivePrefab;                                              
    public  NodeAttrActivePrefab  nodeAttrActivePrefab{get {return _nodeAttrActivePrefab;}}
    private NodeAttrPool _nodeAttrPool;                                                              
    public  NodeAttrPool nodeAttrPool{get {return _nodeAttrPool;}}

    //
    // Constructor running base class constuctor
    public NodeTile(Vector3 worldPosition, int gridX, int gridY)
        : base( worldPosition,  gridX,  gridY) {
           
        //
        // TEST Pooling
        _nodeAttrPool.PoolObject = GameObject.Find ("Cube").name;
        _nodeAttrPool.PoolGroup.NextPoolObj;

    }
           
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public struct NodeAttrPool  {

    private string _poolObject;                              
    public string PoolObject
    {
        get
        {    //
            // Return from private
            return _poolObject;
        }
        set {
            //
            // Set poolName
            PoolName = value;
            //
            // Return to private
            _poolObject = value;
        }
    }
    private string _poolName;                              
    public string PoolName
    {
        get
        {    //
            // Return from private              
            return _poolName;
        }
                          
        set
        {  
            //
            // Create the GOPoolGroup
            if (GameObject.Find (value + "Pool" ) == null) {
                GameObject currentGoPoolGroup = new GameObject (value + "Pool");
                Pool currentPoolGroup = currentGoPoolGroup.AddComponent<Pool> ();
                currentPoolGroup.poolObj = GameObject.Find (value);
                //
                // Set PoolGroup
                PoolGroup = currentPoolGroup;
              
            }
            //
            // Return to private
            _poolName = value + "Pool" ;
        }
    }
    private Pool _poolGroup;                                  
    public Pool PoolGroup
    {
        get
        {    //
            // Return from private
            return _poolGroup;
        }
        set
        {    //
            // Return to private
            _poolGroup = value;
        }
    }
}

 using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class Pool : MonoBehaviour {


    public GameObject poolObj;                                          // Object we want to pool
    public List<GameObject> pooledObjects = new List<GameObject>();        // List of inactive pool objects
    public GameObject NextPoolObj {                                        // GameObject clone = pool.nextThing; triggers get{} & pool.nextThing = gameObject; triggers set{}
        get {
            //
            // Check if we have any avaliabel pooled objects
            if (pooledObjects.Count < 1){

                //
                // If not clone a new one
                GameObject newClone = (GameObject)Instantiate (poolObj);
                newClone.transform.parent = transform;
                newClone.SetActive (false);
                pooledObjects.Add (newClone);

                //
                // Add poolMember script componet to clone, the pool memeber
                // calls pool.nextThing = gameObject; in void OnDisable() whitch
                // fires off set{} and retuns obj to pool.
                PoolMember poolMember = newClone.AddComponent<PoolMember>();
                poolMember.pool = this;

            }
            //
            // If we have an object avaliable in pooledObjects list set it to active, remove from pooledObjects and retun
            GameObject clone = pooledObjects[0];
            pooledObjects.RemoveAt (0);
             clone.SetActive (true);
            return clone;
        }
        set {
            //
            // Returns the object back to pooledObjects by calling  pool.nextThing = gameObject; in void OnDisable()
            value.SetActive (false);
            pooledObjects.Add (value);
        }
    }
}
2

The error points to line 26, but your posted NodeTile code has fewer lines than that. What line is that error actually referencing?

3

Sorry was missing my spaces, all fixed.

It on this line calling ,my nextPoolObj “_nodeAttrPool.PoolGroup.NextPoolObj;”

4

NextPoolObj is a property. If you’re calling it you need to explicitly set or get it.

E.g.

var nextObj = _nodeAttrPool.PoolGroup.NextPoolObj;

or

_nodeAttrPool.PoolGroup.NextPoolObj = myGameObj;
5

The issue is that you have “NextPoolObj” sitting on a line on its own. You need to assign that to something. (If you don’t have anything to assign it to, then why would you be calling it?)

GameObject someObject = _nodeAttrPool.PoolGroup.NextPoolObj;

I will add this: I don’t think that functionality works well as a property. For one, as a general “code style” rule, it’s probably a bad idea for properties to have that much code in them. Properties should be pretty lightweight. They’re convenience features that replacing accessing a member variable, and as such, coders who see them generally make at least two assumptions about it that this property does not adhere to:

  1. It’s lightweight, fast code that I can execute without worrying much about performance costs;
  2. If I will the same property getter twice, I will probably get the same value back both times (like a variable).

If I saw this property in a project I was collaborating on, I would think it was Really Weird ™ and would have expected this to be a function instead.

6

I see ok, thanks for the help, im going to turn this into a funtions

7

Really appreciate all the help guys

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