public static string connectionString;//此处值每次新赋的值都取得到 都正确


    public static SqlConnection Connection
    {
        get
        {
            if (connection == null)
            {
[color=#FF0000]                connection = new SqlConnection(connectionString);//此处connectionString值不变 依然是第一次的值[/color]                try
                {
                    connection.Open();
                }
                catch { }
            }
            else if (connection.State == System.Data.ConnectionState.Closed)
            {
                connection.Open();
            }
            else if (connection.State == System.Data.ConnectionState.Broken)
            {
                connection.Close();
                connection.Open();
            }
            return connection;
        }
    }

class.connectionString="asd";
//第二次赋值
class.connectionString="ABC";