C#

private void saveButton_Click(object sender, RoutedEventArgs e)
{
    Database1DataSet myDataSet = new Database1DataSet();
    
    DataRow myDataRow = myDataSet.Tables["events"].NewRow();//on this line 
    myDataRow["event"] = "new text";
    myDataRow["date"] = mdCalendar.Time();
    myDataSet.Tables["events"].Rows.Add(myDataRow);

}

Object reference not set to an instance of an object.

protected void UpdateControls()
{
    this.SuspendLayout();

    int LastTop = this.AutoScrollPosition.Y;
    foreach (Control ic in _controls)
    {
        ic.Top = LastTop;
        LastTop = ic.Bottom + 5;
    }

    this.ResumeLayout(true);

    if (this.Width != this.NeededWidth)
    {
        this.Width = NeededWidth;
    }
}

public int NeededWidth
{
    get
    {
        if (this.VScroll)
            return _MaxWidth + 17;
        else
            return _MaxWidth;
    }
}

    _ItemsContainer = new MyControl();
    _ItemsContainer.SizeChanged += new EventHandler(_ItemsContainer_SizeChanged);
...
void _ItemsContainer_SizeChanged(object sender, EventArgs e)
{
    _ItemsContainer.Width = _ItemsContainer.NeededWidth;
}