How to Show Substitute Text for Some Values in NumericUpDown?

Question

I made a dialog box that contains a numericupdown control, which has a range of -1~100

I want to show "infinite" for -1 instead of the raw value.

Answer 1

To get the desired behaviour you have to create your own control that inherits from NumericUpDown. To change the text you can override the UpdateEditText method:

public class NumericUpDownEx : NumericUpDown
{
    public NumericUpDownEx()
    {
    }

    protected override void UpdateEditText()
    {
        if (Value < 0)
        {
            Text = "infinite";
        }
        else
        {
            base.UpdateEditText();
        }
    }
}