将结构保存在二进制文件中，然后从中读取

本文关键字：然后 读取 二进制文件 结构 保存 存在 | 更新日期: 2023-09-27 17:59:15

我的程序（在WinForms中）是对某些主题的某种测试。我有这样的结构，我保存我的问题的这个测试：

Dictionary<int, Question> questions = new Dictionary<int, Question>();
public class Question
{
    public Question(string q_text,  Dictionary<string, bool> ans)
    {
        text = q_text;
        answers = ans;
    }
    public string text { get; set; }
    public Dictionary<string, bool> answers { get; set; }       
}

我想把我的问题（确切地说是Dictionary<int, Question> questions = new Dictionary<int, Question>();）保存在二进制文件中，每次我启动程序时，它都会从中读取。我从未使用过二进制文件。

将结构保存在二进制文件中，然后从中读取

您可以序列化对象并将其保存在文件中。但是你必须用[Serializable]标记你的类

using System;
using System.Runtime.Serialization.Formatters.Binary;
using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
/// <summary>
/// Persists the object on HD
/// </summary>
public static void PersistObject()
{
    Logger.Debug("PersistObject: Started");
    // Persist to file
    FileStream stream = File.OpenWrite(_filePath);
    BinaryFormatter formatter = new BinaryFormatter();
    formatter.Serialize(stream, objectToSave);
    stream.Close();
    
    Logger.Debug("PersistObject: Ended");
}
/// <summary>
/// Loads the object.
/// </summary>
public static void LoadObject()
{
    try
    {
        Logger.Debug("LoadObject: Started");
        // Open file to read saved DailyUsers object
        if (File.Exists(_filePath))
        {
            FileStream stream = File.OpenRead(_filePath);
            BinaryFormatter formatter = new BinaryFormatter();
    
            object deserializedObject = formatter.Deserialize(stream);
            stream.Close();
        }
        Logger.Debug("LoadObject: Ended");
    }
    catch (Exception ex)
    {
        Logger.Error(ex, ex.Message);
    }
}

您可以使用序列化来实现这一点，因此请检查以下代码：

   Dictionary<int, Question> questions = new Dictionary<int, Question>();
    [Serializable]
    public class Question
    {
        public Question(string q_text, Dictionary<string, bool> ans)
        {
            text = q_text;
            answers = ans;
        }
        public string text { get; set; }
        public Dictionary<string, bool> answers { get; set; }
        public static void Save(Question q,Stream st)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf =
                new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            bf.Serialize(st, q);
        }
        public static void SaveMany(Dictionary<int, Question> questions,Stream st)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf =
                new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            bf.Serialize(st, questions);
        }
        public static Question Load(Stream st)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf =
                new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            Question q = (Question)bf.Deserialize(st);
            return q;
        }
        public static Dictionary<int, Question> LoadMany(Stream st)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf =
                new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            Dictionary<int, Question> q = (Dictionary<int, Question>)bf.Deserialize(st);
            return q;
        }
    }

您想要使用BinaryFormatter类序列化对象。这篇SO文章将为您提供完成此任务所需的代码。但是要注意，Dictionary<TKey, TValue>是不可序列化的，所以您不会直接序列化它。相反，可以考虑使用List<KeyValuePair<int, Question>>来完成同样的事情。

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