从二进制文件中读取序列化对象

Question

我正在尝试将序列化对象写入和读取到二进制文件。我正在使用 Append FileMode 添加序列化对象，但是当我尝试读取文件时，它只打印一个反序列化对象。

这是我的序列化方法。

public void serialize(){ 
    MyObject obj = new MyObject();
    obj.n1 = 1;
    obj.n2 = 24;
    obj.str = "Some String";
    IFormatter formatter = new BinaryFormatter();
    Stream stream = new FileStream("MyFile.bin", FileMode.Append,                          FileAccess.Write, FileShare.None);
    formatter.Serialize(stream, obj);
    stream.Close()
}

这是我的反序列化方法。

public static void read()
{
    IFormatter formatter = new BinaryFormatter();
    Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
    MyObject obj = (MyObject)formatter.Deserialize(stream);
    stream.Close();

    // Here's the proof.
    Console.WriteLine("n1: {0}", obj.n1);
    Console.WriteLine("n2: {0}", obj.n2);
    Console.WriteLine("str: {0}", obj.str);
}

我们如何遍历文件中的每条序列化记录，就像我们在 C++ 中使用 File.eof() 或 while(file.read()) 一样。

Answer 1

Deserialize 只返回一个对象。您需要创建一个集合并循环，直到到达流的末尾：

List<MyObject> list = new List<MyObject>();
Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
while(stream.Position < stream.Length)
{
     MyObject obj = (MyObject)formatter.Deserialize(stream);
     list.add(obj);
}

Answer 2

上面的解释是正确的，但是我会这样说，使用你喜欢的集合：

    public static void serializeIt()
    { 
        MyObject obj = new MyObject();
        obj.n1 = 1;
        obj.n2 = 24;
        obj.str = "Some String";
        MyObject obj2 = new MyObject();
        obj2.n1 = 1;
        obj2.n2 = 24;
        obj2.str = "Some other String";
        List<MyObject> list = new List<MyObject>();
        list.Add(obj);
        list.Add(obj2);
        IFormatter formatter = new BinaryFormatter();
        Stream stream = new FileStream("MyFile.bin", FileMode.Append,FileAccess.Write, FileShare.None);
        formatter.Serialize(stream, list);
        stream.Close();
    }

    public static void read()
    {
        IFormatter formatter = new BinaryFormatter();
        Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
        List<MyObject> list = (List<MyObject>)formatter.Deserialize(stream);
        stream.Close();

    }

您还应该确保每次序列化集合时都重写 MyFile.bin，因为如果您继续附加它们，它总是会返回首先保存的集合。这应该是唯一的缺点。

Answer 3

谢谢你的帮助，我做了这个。

    using System.IO;
    using System.Runtime.Serialization.Formatters.Binary;

    private static Dictionary<int, ArrayList> J1_CarteDeck;

    private static string PathDocuments = String.Format("{0}\\Antize Game\\", Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));
    private const string FILE_NAME      = "Antize.data";

   public static bool SauvegarderDeck()
   {
       if (!(Directory.Exists(PathDocuments)))
           Directory.CreateDirectory(PathDocuments);

       if (File.Exists(PathDocuments + FILE_Deck))
           File.Delete(PathDocuments + FILE_Deck);

       foreach (ArrayList child in J1_CarteDeck.Values)
       {  
           if(child != null)
           { 
                BinaryFormatter formatter   = new BinaryFormatter();
                FileStream stream           = new FileStream(PathDocuments + FILE_Deck, FileMode.Append, FileAccess.Write, FileShare.None);
                formatter.Serialize(stream, child);
                stream.Close();
            }
        }

        if (File.Exists(PathDocuments + FILE_Deck))
            return true;
        else
            return false;
    }

    public static bool ChargerDeck()
    {
        if (!(File.Exists(PathDocuments + FILE_Deck)))
            return false;

        int cptr = 1;

        J1_CarteDeck                = new Dictionary<int, ArrayList>();

        BinaryFormatter formatter   = new BinaryFormatter();
        Stream stream               = new FileStream(PathDocuments + FILE_Deck, FileMode.Open, FileAccess.Read, FileShare.None);

        while (stream.Position < stream.Length)
        {
            J1_CarteDeck[cptr] = (ArrayList)formatter.Deserialize(stream);
            cptr++;
        }

        stream.Close();

        return true;
    }

Answer 4

简单地遍历二进制文件中的每个对象

using (System.IO.FileStream fs = new System.IO.FileStream("D:\\text\\studentdata.txt", System.IO.FileMode.Open, System.IO.FileAccess.Read))
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter sf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            Object o = sf.Deserialize(fs);
            while (fs.Position < fs.Length)
            {
                o = sf.Deserialize(fs);
                Student student = (o as Student);
                Console.WriteLine("str: {0}", student.sname);
            }
        }