“System.Windows.Forms.TextBox”不包含“Address”的定义，并且找不到可接受类型为“System.Windo,并且找不

 private void textBox3_TextChanged(object sender, EventArgs e)
        {
            System.Net.IPAddress[]addr = IpEntry.AddressList;
            string IPAddress=addr[0].ToString();
            this.IpEntry.Text = IPAddress; 

        }

补充：.NET技术 ,  C#