C# 将链表存入二进制文件及读取二进制文件得到链表示例

// 将tasks保存到二进制文件中
public Boolean saveToFile(String file)
{
    try
    {
        if (tasks.Count==0)
        {
            // 没任务就不存
            return false;
        }


        if (File.Exists(file))
        {
            // 原有文件删掉
            File.Delete(file);
        }

        // 写文件
        FileStream writeStream = new FileStream(file, FileMode.Create);
        BinaryWriter bw = new BinaryWriter(writeStream);

        foreach (Dld tt in tasks)
        {
            bw.Write((String)tt.getID());// 以下强制类型转换并非必要，而是为了阅读时辨别类型
            bw.Write((String)tt.getFilename());
            bw.Write((String)tt.getUrl());
            bw.Write((long)tt.getRemoteFileSize());
            bw.Write((String)tt.getPercent());
            bw.Write((String)tt.getStatus());
            bw.Write((String)tt.getType());
            bw.Flush();
        }

        bw.Close();
        writeStream.Close();

        return true;
    }catch(Exception e){
        throw e;
    }
}

// 从二进制文件中提取tasks
public Boolean loadFromFile(String file)
{
    try
    {
        if (File.Exists(file)==false)
        {
            // 文件不存在直接返回
            return false;
        }

        // 读文件
        FileStream readStream = new FileStream(file, FileMode.Open);
        BinaryReader br = new BinaryReader(readStream);

        try
        {
            while(true)
            {

// 读取过程正好是写入过程的逆序
                String id = br.ReadString();
                String filename = br.ReadString();
                String url = br.ReadString();
                long remoteFileSize = br.ReadInt64();
                String percent = br.ReadString();
                String status = br.ReadString();
                String type = br.ReadString();

                // 这个地方要根据类型判断
                Dld tnew = null;

                if (type.Equals("http"))
                {
                    tnew = new HttpDld(mainGui, id, filename, url, remoteFileSize, type);
                }
                else if (type.Equals("ftp"))
                {
                    tnew = new FtpDld(mainGui, id, filename, url, remoteFileSize, type);
                }

                tnew.setStatus(status);
                tnew.setPercent(percent);

                tasks.Add(tnew);
            };
        }
        catch(EndOfStreamException ex){// 读完会抛出这个异常，正常过程
            System.Console.WriteLine("文件" + file + "读取完毕,读取任务" + tasks.Count+"条.");
        }


        br.Close();
        readStream.Close();

        return true;
    }
    catch (Exception e)
    {
        throw e;
    } 
}