CODEWITHSUNDEEP
c#arraysmultidimensional-array
stalker2106
stalker2106

Reputation: 118

C# IndexOutOfRangeException when calling Array.GetLength(1) for a 2D Array

here is the code, I noticed that the Getlength method returns 0 but I think its normal as the for loop wont go further than 0.. I've written 

int yy = tile.GetLength(1);

and it throws the same exception as the code under :

 TileData[][] tile = GameMain.Level.getCollisionTiles();

        Rectangle tileRectangle;
        for(int x = 0; x <= tile.GetLength(0); x++)
        {
            for (int y = 0; y <= tile.GetLength(1); y++) //EXCEPTION THROWN HERE AT GETLENGTH !!!!
            {
                tileRectangle = tile[x][y].Target;
                if (tileRectangle.Contains(m_hitbox)) //Si il y a collision
                {
                    if ((m_hitbox.X + m_hitbox.Width) > tileRectangle.X) //si le joueur percute par la gauche
                    {
                        m_hitbox.X--;
                    }
                    else if (m_hitbox.X < (tileRectangle.X + tileRectangle.Width)) //Droite
                    {
                        m_hitbox.X++;
                    }
                    if ((m_hitbox.Y + m_hitbox.Height) > tileRectangle.Y) //si le joueur percute par le haut
                    {
                        m_hitbox.Y--;
                    }
                    else if (m_hitbox.Y < (tileRectangle.Y + tileRectangle.Height)) //Bas
                    {
                        m_hitbox.Y++;
                    }
                }
            }
        }

EDIT: I got it working by getting the tile info from the map object, but now it throws NullReferenceException

        TileData[][] tile = GameMain.Level.getCollisionTiles();
        int xMax = GameMain.Level.getMapHeight();
        int yMax = GameMain.Level.getMapWidth();

        for (int x = 0; x <= xMax; x++)
        {
            for (int y = 0; y <= yMax; y++)
            {
                Rectangle tileRectangle = tile[x][y].Target; //THIS LINE FAILS !!!!
                if (tileRectangle.Contains(m_hitbox)) //Si il y a collision
                {
                    if ((m_hitbox.X + m_hitbox.Width) > tileRectangle.X) //si le joueur percute par la gauche
                    {
                        m_hitbox.X--;
                    }
                    else if (m_hitbox.X < (tileRectangle.X + tileRectangle.Width)) //Droite
                    {
                        m_hitbox.X++;
                    }
                    if ((m_hitbox.Y + m_hitbox.Height) > tileRectangle.Y) //si le joueur percute par le haut
                    {
                        m_hitbox.Y--;
                    }
                    else if (m_hitbox.Y < (tileRectangle.Y + tileRectangle.Height)) //Bas
                    {
                        m_hitbox.Y++;
                    }
                }
            }
        }

Sorry to ask you this question in the same topic, but i think you can help me resolving it fast.

Upvotes: 2

Views: 1427

Answers (1)

Adriano Repetti
Adriano Repetti

Reputation: 67080

It's not a 2D array. TileData[][] is a jagged array, TileData[,] is a 2D array then, in your case, GetLength(1) will always fail because tile has only one dimension.

EDIT
What to do to solve this? You can change tile from [][] to [,] (for example) and keep everything else as is (how getCollisionTiles() works?) or you may update your code to get right size from jagged array, like this:

for (int y = 0; y < tile[x].GetLength(0); y++)

BTW you may even replace GetLength(0) with a simple Length:

for(int x = 0; x < tile.Length; x++)
{
    for (int y = 0; y < tile[x].Length; y++)

Final note: for 0 based arrays Length is not inclusive for index so x <= tile.Length must be replaced with x < tile.Length.

Upvotes: 8

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