数组索引超出范围，但应进行定义。编程新手

Question

这里的第一篇文章。

我正在自学C#和unity，并致力于开发一款类似于bejewelled的"match-3“风格的游戏。我已经根据教程编写了下面发布的所有代码，但是我自己和评论区中的其他人都遇到了数组超出范围的问题。

正如编译器所说的那样，错误。

IndexOutOfRangeException: Array index is out of range.
CreateGame.CheckGrid () (at Assets/Scripts/CreateGame.cs:181)
CreateGame.Update () (at Assets/Scripts/CreateGame.cs:229)

下面粘贴了CreateGame.cs的完整代码(整个项目中唯一的脚本)。但为了帮助你，我可以说，从我的研究来看，当你搜索没有存储在数组中的东西时，就会发生索引溢出。作为C#的新手，我只有两个项目(也来自教程)，我缺乏如何实际解决这个问题的技术知识。

据我所知，当数组小于0 (比如负值)时，编译器会返回这个错误，因为-1显然超出了范围。

我认为罪魁祸首与这些if语句有关，特别是我们从c整数中减去1的情况。

if (tiles[c, r] != null && tiles[c - 1, r] != null)

但是，上面的代码嵌套在这个for语句中

for (int c = 0; c < cols; c++)

所以C的值永远不应该小于0，或者我误解了这个for语句的逻辑，c从0开始，如果它小于cols变量，就加1，或者当c=0时，它先完成for循环。我不太确定如何解决这个问题。

值得一提的是，数组大小在我工作的场景内的GameObject (在检查器中)上定义为4，并且我有4个单独的对象预置分配给tiles数组的4个值，并将它们的位置存储在tiles数组中(如代码中所示)。此外，cs脚本仅附加到单个游戏对象，因此没有代码运行的多个实例。

抱歉，如果这篇文章组织得不够好，我才学了一个星期。

感谢您的关注！:)

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

public class Tile
{
    public GameObject tileObj;
    public string type;
    public Tile(GameObject obj, string t)
    {
        tileObj = obj;
        type = t;
    }

}

public class CreateGame : MonoBehaviour
{
    GameObject tile1 = null;
    GameObject tile2 = null;

    public GameObject[] tile;
    List<GameObject> tileBank = new List<GameObject> ();

    static int rows = 8;
    static int cols = 8;
    bool renewBoard = false;
    Tile[,] tiles = new Tile[cols, rows];

    void Start()
    {

        //List population
        int numCopies = (rows * cols) / 3;
        for (int i = 0; i < numCopies; i++)
        {
            for(int j = 0; j < tile.Length; j++) // J becomes the int = to number of tile prefabs added
            {
                GameObject o = (GameObject)Instantiate 
                    (tile [j], new Vector3 (-10, -10, 0), tile [j].transform.rotation); // creates a clone tile of the screen
                o.SetActive (false);
                tileBank.Add (o); // adds tile (game object called o) to the array (not shuffled)
            }
        }

        ShuffleList(); //Shuffles the list of tile-bank after the list has been populated

        //Populates rows and columns with tiles from tileBank array
        for (int r = 0; r < rows; r++)
        {
            for (int c = 0; c < cols; c++)
            {
                Vector3 tilePos = new Vector3 (c - 2, r - 4, 0); //creates tiles with an offset ( -2x and -4y) to place them in scene
                for (int n = 0; n < tileBank.Count; n++)
                {
                    GameObject o = tileBank [n];
                    if (!o.activeSelf) // if the tile is not active move it and make it active
                    {
                        o.transform.position = new Vector3 (tilePos.x, tilePos.y, tilePos.z); //moves tile into position, it was stored inactive at -10,-10
                        o.SetActive (true);
                        tiles[c, r] = new Tile (o, o.name); //Stores tile back into array
                        n = tileBank.Count + 1; //Update tile count
                    }
                }

            }
        }
    }

    //Shuffles the order of the array storing the tiles
    void ShuffleList()
    {
        System.Random rand = new System.Random ();
        int r = tileBank.Count;
        while (r > 1)
        {
            r--;
            int n = rand.Next (r + 1);
            GameObject val = tileBank [n];
            tileBank [n] = tileBank [r];
            tileBank [r] = val;
        }
    }

    //checks for missing tiles and adds new ones from array, also drops tiles down if there is an opening
    void RenewGrid()
    {
        bool anyMoved = false;
        ShuffleList ();
        for (int r = 1; r < rows; r++)
        {
            for (int c = 0; c < cols; c++)
            {
                if (r== rows - 1 && tiles[c, r] == null)
                    //if in the top row and there are no tiles
                {
                    Vector3 tilePos = new Vector3 (c, r, 0);
                    for (int n = 0; n < tileBank.Count; n++)
                    {
                        GameObject o = tileBank [n];
                        if (!o.activeSelf)
                        {
                            o.transform.position = new Vector3 (tilePos.x, tilePos.y, tilePos.z);
                            o.SetActive (true);
                            tiles [c, r] = new Tile (o, o.name);
                            n = tileBank.Count + 1;
                        }
                    }
                }
                if (tiles[c, r - 1] != null)
                {
                    if (tiles[c, r - 1] == null)
                        //drop down if space below is empty
                    {
                        tiles [c, r - 1] = tiles [c, r];
                        tiles [c, r - 1].tileObj.transform.position = new Vector3 (c, r - 1, 0);
                        tiles [c, r] = null;
                        anyMoved = true;
                    }
                }
            }
        }
        if (anyMoved)
        {
            Invoke ("RenewGrid", 0.5f);
        }
    }


    void CheckGrid()
    {
        int counter = 1;
        //check in columns for matches
        for (int r = 0; r < rows; r++) //repeats function until you have satisfied the number of rows
        {
            counter = 1;
            for (int c = 1; c < cols; c++)
            {
                if (tiles[c, r] != null && tiles[c - 1, r] != null) //if the tiles exist (not null)
                {
                    if (tiles[c, r].type == tiles [c - 1, r].type) //if there is a match add 1 to the counter for match checks
                    {
                        counter++;
                    }
                    else
                    {
                        counter = 1; //reset counter
                    }

                    //if a match is found remove tiles
                    if (counter == 3)
                    {
                        if (tiles [c, r] != null)
                        {
                            tiles [c, r].tileObj.SetActive(false);
                        }

                        if (tiles [c - 1, r] !=null)
                        {
                            tiles [c - 1, r].tileObj.SetActive(false);
                        }

                        if (tiles [c - 2, r] !=null)
                        {
                            tiles [c - 2, r].tileObj.SetActive(false);
                        }

                        tiles[c , r] = null; // changes values to null in the 2D matrix
                        tiles[c - 1, r] = null;
                        tiles[c - 2, r] = null;
                        renewBoard = true;

                    }
                }
            }
        }

        //check in rows for matches
        for (int c = 0; c < cols; c++)
        {
            counter = 1;
            for (int r = 1; c < rows; r++)
            {
                if (tiles[c, r] != null && tiles[c - 1, r] != null) //if the tiles exist (not null)
                {
                    if (tiles[c, r].type == tiles [c - 1, r].type) //if there is a match add 1 to the counter for match checks
                    {
                        counter++;
                    }
                    else
                    {
                        counter = 1; //reset counter
                    }

                    //if a match is found remove tiles
                    if (counter == 3)
                    {
                        if (tiles [c, r] != null)
                        {
                            tiles [c, r].tileObj.SetActive(false);
                        }

                        if (tiles [c, r - 1] !=null)
                        {
                            tiles [c, r - 1].tileObj.SetActive(false);
                        }

                        if (tiles [c, r - 2] !=null)
                        {
                            tiles [c, r - 2].tileObj.SetActive(false);
                        }

                        tiles[c, r] = null; // changes values to null in the 2D matrix
                        tiles[c, r - 1] = null;
                        tiles[c, r - 2] = null;
                        renewBoard = true;

                    }
                }
            }
        }

        if(renewBoard)
        {
            RenewGrid();
            renewBoard = false;
        }
    }

    void Update()
    {
        CheckGrid ();

        if (Input.GetMouseButtonDown(0))
        {
            Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition); //casts a ray from mouse position
            RaycastHit2D hit = Physics2D.GetRayIntersection (ray, 1000); //tests for ray hit
            if (hit)
            {
                tile1 = hit.collider.gameObject; //changes tile1 null to the gameObject who's collider was hit
            }
        }

        // if mouse button up detected after an initial tile has been hit with ray
        else if (Input.GetMouseButtonUp(0) && tile1)
        {
            Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition);
            RaycastHit2D hit = Physics2D.GetRayIntersection (ray, 1000);

            if (hit)
            {
                tile2 = hit.collider.gameObject; //changes tile2 nulle to the gameObject who's collider was hit
            }

            if (tile1 && tile2) //If we has two tile values clicked, swap them
            {
                //check to see that distance of clicked tiles is not greater than 1 tile
                int horzDist = (int)Mathf.Abs (tile1.transform.position.x - tile2.transform.position.x);
                int vertDist = (int)Mathf.Abs (tile1.transform.position.y - tile2.transform.position.y);

                if (horzDist == 1 ^ vertDist == 1) // X-OR Statment, IF 1 , OR 1, but NOT BOTH
                {
                    //get tile 1's array position
                    Tile temp = tiles [(int)tile1.transform.position.x, (int)tile1.transform.position.y];
                    //change tile 1's array position to now be tile 2's array position
                    tiles [(int)tile1.transform.position.x, (int)tile1.transform.position.y] = 
                    tiles [(int)tile2.transform.position.x, (int)tile2.transform.position.y];
                    //change tile 2's array position to now be tile 1's old array position
                    tiles [(int)tile2.transform.position.x, (int)tile2.transform.position.y] = temp;


                    Vector3 tempPos = tile1.transform.position; //get tile 1's GameObject position
                    tile1.transform.position = tile2.transform.position; //change tile 1 to tile 2's GameObject position
                    tile2.transform.position = tempPos; //change tile 2 to tile 1's GameObject position
                    //reset clicked tiles
                    tile1 = null;
                    tile2 = null;
                }
                else
                {
                    GetComponent<AudioSource> ().Play (); // Play error sound when illegal swap attempted
                }
            }
        }
    }
}

Answer 1

错误只是在for语句中使用了不正确的变量。

for (int r = 1; c < rows; r++)

应该是

for (int r = 1; r < rows; r++)