为什么不简单地使用NumericUpDown控件或自定义NumericUpDown（它没有微调器，但具有int的AsInteger属性）来禁止非数字值。

public class SpecialNumericUpDown : NumericUpDown
{

        public SpecialNumericUpDown()
        {
            Controls[0].Hide();
            TextAlign = HorizontalAlignment.Right;
            // optionally set min and max values here or in the property window
        }
        protected override void OnTextBoxResize(object source, EventArgs e)
        {
            Controls[1].Width = Width - 4;
        }
    
        [Browsable(false)] public int AsInteger => (int)Value;
    
        public delegate void TriggerDelegate();
    
        public event TriggerDelegate TriggerEvent;
        protected override void OnKeyDown(KeyEventArgs e)
        {
            if (e.KeyCode == (Keys.Return))
            {
                e.Handled = true;
                e.SuppressKeyPress = true;
    
                TriggerEvent?.Invoke();
    
                return;
            }
    
            base.OnKeyDown(e);
        }
    
    }