Question

我需要做的是在内存中创建一个文件，写入该文件，然后像访问任何其他文件一样访问该文件。

我在这里创建并使用实际文件：

if (!File.Exists(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")))
{
    File.Create(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")).Dispose();
    using (TextWriter tw = new StreamWriter(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")))
    {
        foreach (string[] array in listOfRows)
        {
            string dataString = array[0] + "," + array[1] + "," + array[2] + "," + array[3];
            tw.WriteLine(dataString);
        }
        tw.Close();
    }
}
else if (File.Exists(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")))
{
    using (TextWriter tw = new StreamWriter(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")))
    {
        foreach (string[] array in listOfRows)
        {
            string dataString = array[0] + "," + array[1] + "," + array[2] + "," + array[3];
            tw.WriteLine(dataString);
        }
        tw.Close();
    }
}

//makes virtual table to be copied to database
DataTable dt = new DataTable();
string line = null;
int i = 0;
using (StreamReader sr = File.OpenText(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "TEST.csv")))
{
    //etc etc etc
}

正如您所看到的，目前我只是创建一个文件，然后将数据写入其中，然后使用该文件。如果我可以在虚拟内存中完成所有这些操作对我来说会好得多，这可能吗？

Answer 1

好吧，您可以使用MemoryStream读/写字节数组。你没有得到＆＃34; line＆＃34;用这种方法，但它很接近。

话虽如此，如果您正在写作并立即阅读文件，这听起来就像是在兔子洞的下方。文件用于持久性。

如果您只想在内存中存储一系列字符串，则需要使用StringBuilder或者只使用List<T>。

Answer 2

听起来你想要一个内存映射文件（需要.Net 4或更高版本）来自MSDN：

using System;
using System.IO;
using System.IO.MemoryMappedFiles;
using System.Runtime.InteropServices;

class Program
{
    static void Main(string[] args)
    {
        long offset = 0x10000000; // 256 megabytes 
        long length = 0x20000000; // 512 megabytes 

        // Create the memory-mapped file. 
        using (var mmf = MemoryMappedFile.CreateFromFile(@"c:\ExtremelyLargeImage.data", FileMode.Open,"ImgA"))
        {
            // Create a random access view, from the 256th megabyte (the offset) 
            // to the 768th megabyte (the offset plus length). 
            using (var accessor = mmf.CreateViewAccessor(offset, length))
            {
                int colorSize = Marshal.SizeOf(typeof(MyColor));
                MyColor color;

                // Make changes to the view. 
                for (long i = 0; i < length; i += colorSize)
                {
                    accessor.Read(i, out color);
                    color.Brighten(10);
                    accessor.Write(i, ref color);
                }
            }
        }
    }
}

public struct MyColor
{
    public short Red;
    public short Green;
    public short Blue;
    public short Alpha;

    // Make the view brighter. 
    public void Brighten(short value)
    {
        Red = (short)Math.Min(short.MaxValue, (int)Red + value);
        Green = (short)Math.Min(short.MaxValue, (int)Green + value);
        Blue = (short)Math.Min(short.MaxValue, (int)Blue + value);
        Alpha = (short)Math.Min(short.MaxValue, (int)Alpha + value);
    }
}

可以在内存中创建文件吗？

2 个答案: