如何使用C＃将任何数据类型的原始数据写入文件？

Question

I'm writing a Windows app in C#. I have a custom data type that I need to write as raw data to a binary file (not text/string based), and then open that file later back into that custom data type.

For example:

Matrix<float> dbDescs = ConcatDescriptors(dbDescsList);

I need to save dbDescs to file blah.xyz and then restore it as Matrix<float> later. Anyone have any examples? Thanks!

Answer 1

As I've mentioned, the options are overwhelming and this question comes with a ton of opinions as far as which one is the best. With that being said, BinaryFormatter could prove to be useful here as it serializes and deserializes object (along with graphs of connected objects) in binary.

Here's the MSDN link that explains the usage: https://msdn.microsoft.com/en-us/library/system.runtime.serialization.formatters.binary.binaryformatter(v=vs.110).aspx

Just in case that link fails down the line and because I'm too lazy to provide my own example, here's an example from MSDN:

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

public class App 
{
    [STAThread]
    static void Main() 
    {
        Serialize();
        Deserialize();
    }

    static void Serialize() 
    {
        // Create a hashtable of values that will eventually be serialized.
        Hashtable addresses = new Hashtable();
        addresses.Add("Jeff", "123 Main Street, Redmond, WA 98052");
        addresses.Add("Fred", "987 Pine Road, Phila., PA 19116");
        addresses.Add("Mary", "PO Box 112233, Palo Alto, CA 94301");

        // To serialize the hashtable and its key/value pairs,  
        // you must first open a stream for writing. 
        // In this case, use a file stream.
        FileStream fs = new FileStream("DataFile.dat", FileMode.Create);

        // Construct a BinaryFormatter and use it to serialize the data to the stream.
        BinaryFormatter formatter = new BinaryFormatter();
        try 
        {
            formatter.Serialize(fs, addresses);
        }
        catch (SerializationException e) 
        {
            Console.WriteLine("Failed to serialize. Reason: " + e.Message);
            throw;
        }
        finally 
        {
            fs.Close();
        }
    }


    static void Deserialize() 
    {
        // Declare the hashtable reference.
        Hashtable addresses  = null;

        // Open the file containing the data that you want to deserialize.
        FileStream fs = new FileStream("DataFile.dat", FileMode.Open);
        try 
        {
            BinaryFormatter formatter = new BinaryFormatter();

            // Deserialize the hashtable from the file and 
            // assign the reference to the local variable.
            addresses = (Hashtable) formatter.Deserialize(fs);
        }
        catch (SerializationException e) 
        {
            Console.WriteLine("Failed to deserialize. Reason: " + e.Message);
            throw;
        }
        finally 
        {
            fs.Close();
        }

        // To prove that the table deserialized correctly, 
        // display the key/value pairs.
        foreach (DictionaryEntry de in addresses) 
        {
            Console.WriteLine("{0} lives at {1}.", de.Key, de.Value);
        }
    }
}

Answer 2

Consider the Json.Net package (you can download it to your project via Nuget; the better way, or get it directly from their website ).

JSON is just a string (text) that holds values for complex objects. It allows you to turn many (not all) objects into savable files easily which then can be pulled back. To serialize into JSON with JSON.net:

Product product = new Product();
product.Name = "Apple";
product.Expiry = new DateTime(2008, 12, 28);
product.Sizes = new string[] { "Small" };

string json = JsonConvert.SerializeObject(product);

And then to deserialize:

var product = JsonConvert.DeserializeObject(json);

To write the json to a file:

using (StreamWriter writer = new StreamWriter(@"C:/file.txt"))
            {
                writer.WriteLine(json);
            }

Answer 3

I am not a Web Developer so I am not sure that JSON is Binary. Isnt it still text based? So here is what I know is a Binary Answer. Hope this Helps!

using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BinarySerializerSample
{
    class Program
    {
        public static void WriteValues(string fName, double[] vals)
        {
            using (BinaryWriter writer = new BinaryWriter(File.Open(fName, FileMode.Create)))
            {
               int len = vals.Length;
               for (int i = 0; i < len; i++)
                   writer.Write(vals[i]);
            }
        }
        public static double[] ReadValues(string fName, int len)
        {
            double [] vals = new double[len];
            using (BinaryReader reader = new BinaryReader(File.Open(fName, FileMode.Open)))
            {

                for (int i = 0; i < len; i++)
                    vals[i] = reader.ReadDouble();
            }
            return vals;
        }

        static void Main(string[] args)
        {
            const double MAX_TO_VARY = 100.0;
            const int NUM_ITEMS = 100;
            const string FILE_NAME = "dblToTestx.bin";
            double[] dblToWrite = new double[NUM_ITEMS];
            Random r = new Random();
            for (int i = 0; i < NUM_ITEMS; i++)
                dblToWrite[i] = r.NextDouble() * MAX_TO_VARY;

            WriteValues(FILE_NAME, dblToWrite);

            double[] dblToRead ;
            dblToRead = ReadValues(FILE_NAME, NUM_ITEMS);

            int j = 0;
            bool areEqual = true;
            while (areEqual && j < NUM_ITEMS)
            {

                areEqual = dblToRead[j] == dblToWrite[j];
                ++j;
            }
            if (areEqual)
                Console.WriteLine("Test Passed: Press any Key to Exit");
            else
                Console.WriteLine("Test Failed: Press any Key to Exit");
            Console.Read();

        }
    }
}