Numericupdown mousewheel event increases decimal more than one increment

Question

I'm trying to override the mousewheel control so that when the mouse wheel is moved up or down it only increases the value in the numericupdown field by 1. I believe it is currently using what is stored in the control panel and increasing/decreasing the value by 3 each time.

I'm using the following code. Even when numberOfTextLinesToMove is only 1 and I see that txtPrice.Value is getting populated as expected, something else is overwriting it because the value I set is not what is displayed in the numericupdown box

void txtPrice_MouseWheel(object sender, MouseEventArgs e)
        {
            int numberOfTextLinesToMove = e.Delta  / 120;
            if (numberOfTextLinesToMove > 0)
            {
                txtPrice.Value = txtPrice.Value + (txtPrice.Increment * numberOfTextLinesToMove);
            }
            else 
            {

                txtPrice.Value = txtPrice.Value - (txtPrice.Increment * numberOfTextLinesToMove);
            }

        }

Answer 1

I recently had this problem, and got around it by changing the increment.

numericUpDown1.Increment = 1m / SystemInformation.MouseWheelScrollLines;

Edit: This is only a good solution if you intend to only use the mousewheel to change the value. To fix this for all situations, you have to override the class. Here's a simple version.

public class NumericUpDownFix : System.Windows.Forms.NumericUpDown
{
    protected override void OnMouseWheel(MouseEventArgs e)
    {
        HandledMouseEventArgs hme = e as HandledMouseEventArgs;
        if (hme != null)
            hme.Handled = true;

        if (e.Delta > 0)
            this.Value += this.Increment;
        else if (e.Delta < 0)
            this.Value -= this.Increment;
    }
}