vs连接数据库时，创建数据库连接对象错误

string str = @"Data Source= DESKTOP-JJL8Q7P';Initial Catalog=test;Integrated Security=sspi";
            conn = new SqlConnection(str);  
            conn.Open();
            return conn;

下面是问题
System.ArgumentException:“Format of the initialization string does not conform to specification starting at index 0.”