WinForms TextBox to accept numbers in a range

Sometime back, I was looking for a TextBox control which can silently accept numbers (positive int only) for a given range (minimum and maximum). I implemented the following simple class to achieve this:

   class NumberTextBox : System.Windows.Forms.TextBox
   {
      private string mPrevious;
      private int mMin;
      private int mMax;

      public NumberTextBox() : this(0, Int32.MaxValue) { }
      public NumberTextBox(int min, int max)
         : base()
      {
         if ((min > max) || min < 0 || max < 0)
         {
            throw new Exception("Minimum and maximum values are not supported");
         }
         mMin = min;
         mMax = max;
         this.Text = min.ToString();
      }

      protected override void OnKeyPress(KeyPressEventArgs e)
      {
         mPrevious = this.Text;
         e.Handled = !char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar);
      }

      protected override void OnTextChanged(EventArgs e)
      {
         if (this.Text == string.Empty)
         {
            return;
         }

         int num;
         if (Int32.TryParse(this.Text, out num))
         {
            if (num > mMax)
            {
               this.Text = mPrevious;
               this.Select(this.Text.Length, 0);
            }
         }
         else
         {
            this.Text = mPrevious;
            this.Select(this.Text.Length, 0);
         }
      }

      protected override void OnLeave(EventArgs e)
      {
         int num;
         if (!Int32.TryParse(this.Text, out num) || num < mMin || num > mMax)
         {
            this.Text = mPrevious;
            // To move the cursor at last
            this.Select(this.Text.Length, 0);
         }
      }
   }

To use this NumberTextBox on your dialog/form, include the above class in the project and replace TextBox with NumberTextBox in your form.