c#的序列化有关问题

c#的序列化问题
  我要序列化一个结构体
            byte[] askdata=new byte[1024];
            AskData askTemperatureData=new AskData();
            askTemperatureData.bt=new byte[4]{23,255,255,1};
            askTemperatureData.s = new ushort[] { 1,1,10};
            askTemperatureData.num = 1;

             BinaryFormatter bf = new BinaryFormatter();  
             MemoryStream stream = new MemoryStream();
             bf.Serialize(stream, askTemperatureData);
             askdata = stream.ToArray();
运行后报错，请问该怎样修改 c# 序列化
[解决办法]
AskData类要标记可序列化，在AskData的类定义上加上[Serializable()]

[Serializable()]
public class AskData
{
..
}