C# DataRow not working

The problem is solved. My installation of Visual C# was corrupt.

try changing that line to...

DataRow drStudent = dsStudenten.Tables["student"].NewRow();


You don't have a "Student" DataTable.  You have a "student" DataTable.  Yes, it is case-sensitive.

Below is the full code as I have it. I have tried just about anything I can think of (I've been working with C# for only 4 month).

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Studenten
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        string instatus;
        string ovnummer;

        DataSet dsStudenten = new DataSet("Studenten");
        DataTable dtStudent = new DataTable("Student");

        private void form1_Load(object sender, EventArgs e)
        {
            dtStudent.Columns.Add("ovnummer", typeof(string));
            dtStudent.Columns.Add("in", typeof(string));
            dsStudenten.Tables.Add(dtStudent);
            dsStudenten.ReadXml("studenten.xml");
        }

        private void BtnAanmelden_Click_1(object sender, EventArgs e)
        {
            DataRow drStudent = dsStudenten.Tables["Student"].NewRow();
            if (CbIn.Checked)
            {
                instatus = "1";
            }
            else
            {
                instatus = "0";
            }
            drStudent["ovnummer"] = TbObnr.Text;
            drStudent["in"] = instatus;
            dsStudenten.Tables["student"].Rows.Add(drStudent);
            LsbStudenten.Items.Add(drStudent[0]);
            TbObnr.Clear();
        }
    }
}

Dear
I think the DataTable you have created in not attached to the dataset. Please llok at the code :

DataSet dsStudent=new DataSet();
DataTable dtStudent=new DataTable();
/* Create Columns and add them to DataTable*/
dsStudent.Tables.Add(dtStudent);

I think it will solve your problem.
Thanks
Happy Coding

I'm sorry, I though that you're german then german language is easiest for you, anyway, I asked in the previous thread
Have you ever instanciate your Student

Student x = new Student(); 

object befor using it ?

please, ether Englisch or Dutch. My German is to crappy. Sorry.

Ich habe eine frage fur Sie, Haben Sie den Student object instansiert, bevor es addiert wird?