KeyNotFoundException在填充dictonary

你好，我想修改字典中的值，但編譯器拋出KeyNotFoundException。我敢肯定，我在字典中聲明瞭這個關鍵字，因爲我打電話給GenerateEmptyChunks()方法，該方法使用塊的填充字典填充字典的位置，並且值爲電平生成器的值。我檢查了debuger，並且Chunks字典對象正確地填充了鍵和值。它是由我的不合作CompareTo方法引起的嗎？如果是，我如何修改CompareTo方法來返回正確的值？KeyNotFoundException在填充dictonary

public Dictionary<WPoint, WChunk> Chunks = new Dictionary<WPoint, WChunk>();

GenerateEmptyChunks（）方法：

public void GenerateEmptyChunks(int Xcount, int Ycount) 
    { 
     for(int x = 0; x <= Xcount; x++) 
     { 
      for (int y = 0; y <= Ycount; y++) 
      { 
       this.Chunks.Add(new WPoint(x, y), new WChunk(x, y)); 
      } 
     } 
    }

AddBlock（）方法，該方法是由電平發生器，用於每個區塊稱爲：

public void AddBlock(WPoint location, int data) 
    { 
     this.Chunks[location.GetChunk()].AddTile(new WTile(location, data)); 
    }

WChunk對象：

public class WChunk 
    { 
     public int ChunkX; 
     public int ChunkY; 
     public SortedDictionary<WPoint, WTile> Tiles = new SortedDictionary<WPoint, WTile>(); 

     public WChunk(int posX, int posY) 
     { 
      ChunkX = posX; 
      ChunkY = posY; 
     } 

     public void AddTile(WTile tile) 
     { 
      Tiles.Add(tile.GetLocation(), tile); 
     } 
    }

WPoint對象：

public class WPoint : IComparable 
    { 
     public float X; 
     public float Y; 

     public WPoint(float x, float y) 
     { 
      X = x; 
      Y = y; 
     } 

     public WPoint GetChunk() 
     { 
      //Oprava pre bloky mensie ako (1,1) 
      if (X <= 16 && Y <= 16) 
      { 
       return new WPoint(0, 0); 
      } 
      else 
      { 
       double pX = (double)(X/16); 
       double pY = (double)(Y/16); 
       return new WPoint((int)Math.Floor(pX), (int)Math.Floor(pY)); 
      } 
     } 

     public int CompareTo(object obj) 
     { 
      WPoint point2 = (WPoint)obj; 
      if (point2.X == this.X && point2.Y == this.Y) 
      { 
       return 0; 
      } 
      else if (point2.X >= this.X && point2.Y >= this.Y) 
      { 
       return -1; 
      } 
      else 
      { 
       return 1; 
      } 
     } 
}

任何想法，爲什麼被拒絕的編譯器按鍵，當他們在字典嗎？

來源

2012-07-19 Matej Kormuth