สร้าง ZIP ในหน่วยความจําด้วย C# และ Aspose.ZIP

dotnet add package Aspose.Zip

using Aspose.Zip;                 // Archive, ArchiveEntry
using Aspose.Zip.Saving;          // DeflateCompressionSettings, CompressionLevel

// File: Program.cs
using System;
using System.IO;
using System.Text;
using Aspose.Zip;
using Aspose.Zip.Saving;

class Program
{
    static void Main()
    {
        // Prepare output buffer
        using var zipBuffer = new MemoryStream();

        // Choose compression (Deflate is the standard ZIP method)
        var deflate = new DeflateCompressionSettings(CompressionLevel.Normal);
        var entrySettings = new ArchiveEntrySettings(deflate);

        using (var archive = new Archive())
        {
            // 1) Add a text file from memory
            using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("Hello from Aspose.ZIP in memory.")))
            {
                archive.CreateEntry("docs/readme.txt", ms, entrySettings);
            }

            // 2) Add a file from disk (streamed; not fully loaded in RAM)
            var sourcePath = "report.pdf"; // ensure it exists
            if (File.Exists(sourcePath))
            {
                using var fs = File.OpenRead(sourcePath);
                archive.CreateEntry("reports/2025/report.pdf", fs, entrySettings);
            }

            // 3) Save the ZIP to our in-memory buffer
            archive.Save(zipBuffer);
        }

        // Use the ZIP bytes as needed (send over network, write to DB, etc.)
        byte[] zipBytes = zipBuffer.ToArray();
        Console.WriteLine($"ZIP size: {zipBytes.Length} bytes");
    }
}

using System.IO;
using Aspose.Zip;
using Aspose.Zip.Saving;

static class InMemoryZipper
{
    public static byte[] ZipFolderToBytes(string sourceFolder, CompressionLevel level = CompressionLevel.Normal)
    {
        if (!Directory.Exists(sourceFolder))
            throw new DirectoryNotFoundException(sourceFolder);

        var deflate = new DeflateCompressionSettings(level);
        var entrySettings = new ArchiveEntrySettings(deflate);

        using var buffer = new MemoryStream();
        using (var archive = new Archive())
        {
            var root = Path.GetFullPath(sourceFolder);
            foreach (var filePath in Directory.GetFiles(root, "*", SearchOption.AllDirectories))
            {
                var rel = Path.GetRelativePath(root, filePath).Replace(Path.DirectorySeparatorChar, '/');
                using var fs = File.OpenRead(filePath);
                archive.CreateEntry(rel, fs, entrySettings);
            }

            archive.Save(buffer);
        }
        return buffer.ToArray();
    }
}

// File: Program.cs (minimal API)
using System.Text;
using Aspose.Zip;
using Aspose.Zip.Saving;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/download-zip", () =>
{
    using var buffer = new MemoryStream();
    var deflate = new DeflateCompressionSettings(CompressionLevel.Normal);
    var settings = new ArchiveEntrySettings(deflate);

    using (var archive = new Archive())
    {
        // Add dynamic content (for example, a CSV generated on the fly)
        using (var ms = new MemoryStream(Encoding.UTF8.GetBytes("id,name\n1,Alice\n2,Bob\n")))
            archive.CreateEntry("data/users.csv", ms, settings);

        // Add a static file from disk if available
        var logo = "wwwroot/logo.png";
        if (File.Exists(logo))
        {
            using var fs = File.OpenRead(logo);
            archive.CreateEntry("assets/logo.png", fs, settings);
        }

        archive.Save(buffer);
    }

    buffer.Position = 0; // rewind for reading
    return Results.File(
        fileContents: buffer.ToArray(),
        contentType: "application/zip",
        fileDownloadName: $"bundle-{DateTime.UtcNow:yyyyMMdd-HHmmss}.zip");
});

app.Run();

app.MapGet("/stream-zip", async (HttpContext ctx) =>
{
    ctx.Response.ContentType = "application/zip";
    ctx.Response.Headers.ContentDisposition = $"attachment; filename=\"bundle.zip\"";

    var deflate = new DeflateCompressionSettings(CompressionLevel.Normal);
    var settings = new ArchiveEntrySettings(deflate);

    using var archive = new Archive();

    // Add entries...
    using var ms = new MemoryStream(Encoding.UTF8.GetBytes("hello"));
    archive.CreateEntry("hello.txt", ms, settings);

    // Stream directly to the client without buffering full ZIP in RAM
    await archive.SaveAsync(ctx.Response.Body);
});

var fastest = new DeflateCompressionSettings(CompressionLevel.Low);      // fastest, larger files
var balanced = new DeflateCompressionSettings(CompressionLevel.Normal);  // default balance
var smallest = new DeflateCompressionSettings(CompressionLevel.High);    // slowest, smallest files

using System.IO;
using Aspose.Zip;
using Aspose.Zip.Saving;

static void AddLargeGeneratedEntry(Archive archive, string name)
{
    // simulate a big stream produced incrementally
    using var temp = new FileStream(Path.GetTempFileName(), FileMode.Create, FileAccess.ReadWrite, FileShare.None, 81920, FileOptions.DeleteOnClose);
    using var writer = new StreamWriter(temp);
    for (int i = 0; i < 200_000; i++) writer.WriteLine($"row-{i},value-{i}");
    writer.Flush();
    temp.Position = 0;

    var settings = new ArchiveEntrySettings(new DeflateCompressionSettings(CompressionLevel.Normal));
    archive.CreateEntry(name, temp, settings);
}