1 先构建一个类，内容如下：

 

namespace TravelForm{    public sealed class Setting    {        private static volatile Setting instance;        private static object syncRoot = new Object();        private Setting() { }        public static Setting Instance        {            get            {                if (instance == null)                {                    lock (syncRoot)                    {                        if (instance == null)                            instance = new Setting();                    }                }                return instance;            }        }        public string UserName;    }}

2 在窗体1中赋值:

 

 

Setting m_set = Setting.Instance;

m_set.UserName = "test";

 

3 在窗体2 中 取值：

 

 

Setting m_set = Setting.Instance;string request = m_set.UserName;