Winform不用窗体之间传值

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;