Undefined object reference for an object instance. Array

Asked

Viewed 115 times

0

Hi, My problem is in the array following this code:

mesh meshCube;
string[] file = File.ReadAllLines("object.mind");
foreach (string filetext in file)
{
    if (filetext.Contains("v"))
    {
        string ext = filetext.Substring(filetext.IndexOf(" ") + 1);
        string[] pos = ext.Split(' ');
        // erro nessa linha ↓
        meshCube.tris.Add( new triangle (
            new vec3d(float.Parse(pos[0]), float.Parse(pos[1]), float.Parse(pos[2])),
            new vec3d(float.Parse(pos[3]), float.Parse(pos[4]), float.Parse(pos[5])),
            new vec3d(float.Parse(pos[6]), float.Parse(pos[7]), float.Parse(pos[8])))
        );
     }
}

public class vec3d
{
    public vec3d(float x, float y, float z)
    {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    public float x { get; set; }
    public float y { get; set; }
    public float z { get; set; }
}
public class triangle
{
    public triangle(vec3d one, vec3d two, vec3d three)
    {
        p = new[] { one, two, three };
    }
    public vec3d[] p = new vec3d[3];
}
public class mesh
{
    public List<triangle> tris = new List<triangle>();
}
c# array nullpointerexception
  • 1

    Hello @autergame Welcome to Stackoverflow, what is your problem? what have you tried to solve? what is the result of these attempts? please add these answers to your question to make it clearer, I suggest you read [Ask] and [mcve]

  • Hello, where exactly does the mistake happen and what do you really need? explains a little about your business rule...

1 answer

1


You declared the variable meshCube but did not load the variable with any object, so it gives the error NullPointerException while trying to use it:

mesh meshCube;

// [...]

        // erro nessa linha ↓
        meshCube.tris.Add( new triangle (
            new vec3d(float.Parse(pos[0]), float.Parse(pos[1]), float.Parse(pos[2])),
            new vec3d(float.Parse(pos[3]), float.Parse(pos[4]), float.Parse(pos[5])),
            new vec3d(float.Parse(pos[6]), float.Parse(pos[7]), float.Parse(pos[8])))
        );

State in this way that you must resolve that problem:

mesh meshCube = new mesh();

It is worth mentioning that it would be interesting to check whether the array pos contains the amount of items required before to use it:

if (filetext.Contains("v"))
{
    string ext = filetext.Substring(filetext.IndexOf(" ") + 1);
    string[] pos = ext.Split(' ');
    // Verifica se o array contém a quantidade adequada de itens.
    if (pos.Length == 9)
    {
        meshCube.tris.Add( new triangle (
            new vec3d(float.Parse(pos[0]), float.Parse(pos[1]), float.Parse(pos[2])),
            new vec3d(float.Parse(pos[3]), float.Parse(pos[4]), float.Parse(pos[5])),
            new vec3d(float.Parse(pos[6]), float.Parse(pos[7]), float.Parse(pos[8])))
        );
    }

Because it can cause other mistakes too.

Browser other questions tagged c# array nullpointerexception

You are not signed in. Login or sign up in order to post.