C＃IndexOutOfRangeException錯誤

Question

這裏有輕微的C＃問題。 我目前正在用Unity編寫一個小平臺遊戲，並且我有一些raycast檢查了碰撞等。現在

，我開始清理一下代碼，這些光線投射的結果存儲到一個整數數組，但我發現了一個IndexOutOfRangeException。

我試着通過我的代碼多次讀取，但似乎無法找到是什麼原因造成的問題。如果有人能幫助我，我會很高興。

這裏是我的代碼：

using UnityEngine; 
using System.Collections; 

public class PlayerRayCaster : MonoBehaviour { 

    public float playerHeight = 1; 
    public enum FeetState {Air, Ground}; 

    public FeetState playerFeetState = FeetState.Air; 
    public int feetHitRays; 
    public int behindHitRay; 

    //Arrays of rays. value of 1 means that ray hits a target, 0 means that it does not hit. 
    public int[] sideRays; // [0-3] = Left side. [4-8] = Right side. 
    public int[] depthRays; // [0] = Away from camera. [1] = Towards camera. 
    public int[] feetRays; 

    public int counter; 

    void Start(){ 
     sideRays = new int[8]; 
     depthRays = new int[2]; 
     feetRays = new int[3]; 

    } 
    // Update is called once per frame 
    void Update() { 
     FeetRays(); 
     SideRays(); 
     BehindRay(); 
    } 

    //Rays, which check if the character is bumping into an object, left or right. 
    void SideRays(){ 

     float rayLength = 0.4f; 
     counter = 0; 

     //Left side rays. 
     for(int rayHeight = 0 ; rayHeight>=-4 ; rayHeight-=1 , counter++){ 
      Debug.Log(sideRays[counter]); 
      if(Physics.Raycast(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(-1,0,0),rayLength)){ 
       sideRays[counter] = 1; 
       Debug.DrawRay(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(-rayLength,0,0), Color.green); 
      } 
      else{ 
       sideRays[counter] = 0; 
       Debug.DrawRay(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(-rayLength,0,0), Color.yellow); 
      } 
     } 

     //Right side rays. 
     for(int rayHeight = 0;rayHeight>=-4;rayHeight-=1,counter++){ 
      if(Physics.Raycast(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(1,0,0),rayLength)){ 
       sideRays[counter] = 1; 
       Debug.DrawRay(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(rayLength,0,0), Color.green); 
      } 
      else{ 
       sideRays[counter] = 0; 
       Debug.DrawRay(transform.position-new Vector3(0,rayHeight/2,0), new Vector3(rayLength,0,0), Color.yellow); 
      } 
     } 
    } 

    //Three rays, which check if the characters feet are on the ground or not. 
    void FeetRays(){ 
     feetHitRays = 0; 
     float rayLength = 0.2f; 
     //Shoots three rays down from player. 
     for(float i=-0.7f;i<=0.7f;i+=0.7f){ 

      if(Physics.Raycast(transform.position-new Vector3(i/2,0,0), new Vector3(0,-1,0),rayLength)){ 
       feetHitRays++; 
       Debug.DrawRay(transform.position-new Vector3(i/2,0,0), new Vector3(0,-rayLength,0), Color.green); 
      } 
      else{ 
       Debug.DrawRay(transform.position-new Vector3(i/2,0,0), new Vector3(0,-rayLength,0), Color.red); 
      } 
     } 

     //Sets the feet state. 
     if(feetHitRays==0) 
     { 
      playerFeetState = PlayerRayCaster.FeetState.Air; 
     } 
     else{ 
      playerFeetState = PlayerRayCaster.FeetState.Ground; 
     }  
    } 
    //Shoots a raycast in z-direction from the character, to check for door access. 
    void BehindRay(){ 

     behindHitRay = 0; 
     float rayLength = 2; 

     if(Physics.Raycast(transform.position, new Vector3(0,0,1), rayLength)){ //Away from camera 
      behindHitRay = 1; 
      Debug.DrawRay(transform.position, new Vector3(0,0,rayLength), Color.green); 
     } 
     if(Physics.Raycast(transform.position, new Vector3(0,0,-1), rayLength)){ // Towards camera. 
      behindHitRay = -1; 
      Debug.DrawRay(transform.position, new Vector3(0,0,-rayLength), Color.green); 
     } 
    } 
} 

這是一個讓我異常的行：

sideRays[counter] = 1; 

在此先感謝。

Answer 1

我認爲這就是問題所在：

for(int rayHeight = 0 ; rayHeight>=-4 ; rayHeight-=1 , counter++) 

你基本上做的兩倍，這意味着迭代，而你的數組初始化是這樣的：

sideRays = new int[8]; 

你可能很想：

// Note the > instead of >= 
for (int rayHeight = 0; rayHeight > -4; rayHeight--, counter++) 

（順便說一句， d 非常強烈建議您不要使用公共字段，但是這是一個不同的問題。）

Answer 2

您的大小爲8申報sideRays，但它從你的循環快速瀏覽該計數器可以得到儘可能看起來高達10

Answer 3

檢查for(int rayHeight = 0;rayHeight>=-4;rayHeight-=1,counter++){您的界限最終你會訪問數組5次，每次循環以及您所定義的數組有8個項目。訪問9和10會引發異常。