2026年の文書生成に最適なC#ライブラリの選択

// GemBox.Spreadsheet handles XLSX/CSV with formula recalculation and PDF export.
// NuGet: Install-Package GemBox.Bundle
using GemBox.Spreadsheet;

class Program
{
    static void Main()
    {
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY");

        ExcelFile book = new ExcelFile();
        ExcelWorksheet sheet = book.Worksheets.Add("Revenue");

        sheet.Cells["A1"].Value = "Region";
        sheet.Cells["B1"].Value = "Revenue";
        sheet.Cells["A2"].Value = "EMEA";
        sheet.Cells["B2"].Value = 120000;
        sheet.Cells["B4"].Formula = "=SUM(B2:B3)";

        book.Save("revenue.xlsx");
        book.Save("revenue.pdf");
    }
}

Imports GemBox.Spreadsheet

Module Program

    Sub Main()
        SpreadsheetInfo.SetLicense("FREE-LIMITED-KEY")

        Dim book As New ExcelFile()
        Dim sheet As ExcelWorksheet = book.Worksheets.Add("Revenue")

        sheet.Cells("A1").Value = "Region"
        sheet.Cells("B1").Value = "Revenue"
        sheet.Cells("A2").Value = "EMEA"
        sheet.Cells("B2").Value = 120000
        sheet.Cells("B4").Formula = "=SUM(B2:B3)"

        book.Save("revenue.xlsx")
        book.Save("revenue.pdf")
    End Sub

End Module

// NuGet: Install-Package IronXL.Excel
using IronXL;

class Program
{
    static void Main()
    {
        WorkBook workbook = WorkBook.Create(ExcelFileFormat.XLSX);
        WorkSheet sheet = workbook.CreateWorkSheet("Sales");

        sheet["A1"].Value = "Product";
        sheet["B1"].Value = "Units";
        sheet["A2"].Value = "Widget A";
        sheet["B2"].Value = 1024;
        sheet["A3"].Value = "Widget B";
        sheet["B3"].Value = 768;
        sheet["B4"].Formula = "=SUM(B2:B3)";

        workbook.EvaluateAll();
        workbook.SaveAs("sales.xlsx");
    }
}

Imports IronXL

Module Program
    Sub Main()
        Dim workbook As WorkBook = WorkBook.Create(ExcelFileFormat.XLSX)
        Dim sheet As WorkSheet = workbook.CreateWorkSheet("Sales")

        sheet("A1").Value = "Product"
        sheet("B1").Value = "Units"
        sheet("A2").Value = "Widget A"
        sheet("B2").Value = 1024
        sheet("A3").Value = "Widget B"
        sheet("B3").Value = 768
        sheet("B4").Formula = "=SUM(B2:B3)"

        workbook.EvaluateAll()
        workbook.SaveAs("sales.xlsx")
    End Sub
End Module

// GemBox.Document creates and converts DOCX/PDF/RTF/HTML/ODT without Office.
using GemBox.Document;

class Program
{
    static void Main()
    {
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        DocumentModel doc = new DocumentModel();
        doc.Sections.Add(new Section(doc,
            new Paragraph(doc, "Quarterly Report") { ParagraphFormat = { Style = doc.Styles[StyleTemplateType.Heading1] } },
            new Paragraph(doc, "Generated from .NET with no Microsoft Word dependency.")
        ));

        doc.Save("report.pdf");
    }
}

Imports GemBox.Document

Module Program

    Sub Main()
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        Dim doc As New DocumentModel()
        doc.Sections.Add(New Section(doc,
            New Paragraph(doc, "Quarterly Report") With {.ParagraphFormat = New ParagraphFormat() With {.Style = doc.Styles(StyleTemplateType.Heading1)}},
            New Paragraph(doc, "Generated from .NET with no Microsoft Word dependency.")
        ))

        doc.Save("report.pdf")
    End Sub

End Module

// NuGet: Install-Package IronWord
using IronWord;
using IronWord.Models;

class Program
{
    static void Main()
    {
        var doc = new WordDocument();

        var heading = new Paragraph();
        heading.AddChild(new TextRun("Quarterly Report — Q1 2026") { FontSize = 18, Bold = true });
        doc.AddParagraph(heading);

        var body = new Paragraph();
        body.AddChild(new TextRun("Revenue grew 14% quarter-over-quarter."));
        doc.AddParagraph(body);

        doc.SaveAs("report.docx");
    }
}

Imports IronWord
Imports IronWord.Models

Module Program
    Sub Main()
        Dim doc As New WordDocument()

        Dim heading As New Paragraph()
        heading.AddChild(New TextRun("Quarterly Report — Q1 2026") With {.FontSize = 18, .Bold = True})
        doc.AddParagraph(heading)

        Dim body As New Paragraph()
        body.AddChild(New TextRun("Revenue grew 14% quarter-over-quarter."))
        doc.AddParagraph(body)

        doc.SaveAs("report.docx")
    End Sub
End Module

// GemBox.Pdf reads, edits, and merges PDFs without Adobe.
using GemBox.Pdf;

class Program
{
    static void Main()
    {
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        using PdfDocument combined = new PdfDocument();

        foreach (string path in new[] { "invoice.pdf", "terms.pdf", "appendix.pdf" })
        {
            using PdfDocument part = PdfDocument.Load(path);
            combined.Pages.AddClone(part.Pages);
        }

        combined.Save("merged.pdf");
    }
}

Imports GemBox.Pdf

Module Program

    Sub Main()
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        Using combined As New PdfDocument()

            For Each path As String In {"invoice.pdf", "terms.pdf", "appendix.pdf"}
                Using part As PdfDocument = PdfDocument.Load(path)
                    combined.Pages.AddClone(part.Pages)
                End Using
            Next

            combined.Save("merged.pdf")
        End Using
    End Sub

End Module

// NuGet: Install-Package IronPdf
// Docs: https://ironpdf.com/how-to/merge-or-split-pdfs/
using IronPdf;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        // PdfDocument.Merge accepts an array or params list of PdfDocument objects.
        // Order is preserved, and metadata, bookmarks, and annotations are retained.
        string[] inputs = { "invoice.pdf", "terms.pdf", "appendix.pdf" };

        List<PdfDocument> parts = new List<PdfDocument>();
        foreach (string path in inputs)
            parts.Add(PdfDocument.FromFile(path));

        PdfDocument merged = PdfDocument.Merge(parts.ToArray());
        merged.SaveAs("contract-package.pdf");
    }
}

Imports IronPdf
Imports System.Collections.Generic

Module Program
    Sub Main()
        ' PdfDocument.Merge accepts an array or params list of PdfDocument objects.
        ' Order is preserved, and metadata, bookmarks, and annotations are retained.
        Dim inputs As String() = {"invoice.pdf", "terms.pdf", "appendix.pdf"}

        Dim parts As New List(Of PdfDocument)()
        For Each path As String In inputs
            parts.Add(PdfDocument.FromFile(path))
        Next

        Dim merged As PdfDocument = PdfDocument.Merge(parts.ToArray())
        merged.SaveAs("contract-package.pdf")
    End Sub
End Module

// GemBox.Email handles MSG/EML plus SMTP/POP/IMAP — useful for transactional mail flows.
using GemBox.Email;
using GemBox.Email.Smtp;

class Program
{
    static void Main()
    {
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        MailMessage msg = new MailMessage
        {
            From = "billing@example.com",
            Subject = "Invoice 44213",
            BodyHtml = "<p>Your invoice is attached.</p>"
        };
        msg.To.Add("customer@example.com");
        msg.Attachments.Add(new Attachment("invoice.pdf"));

        using SmtpClient smtp = new SmtpClient("smtp.example.com", 587);
        smtp.Connect();
        smtp.Authenticate("billing@example.com", "secret");
        smtp.SendMessage(msg);
    }
}

Imports GemBox.Email
Imports GemBox.Email.Smtp

Module Program

    Sub Main()
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        Dim msg As New MailMessage With {
            .From = "billing@example.com",
            .Subject = "Invoice 44213",
            .BodyHtml = "<p>Your invoice is attached.</p>"
        }
        msg.To.Add("customer@example.com")
        msg.Attachments.Add(New Attachment("invoice.pdf"))

        Using smtp As New SmtpClient("smtp.example.com", 587)
            smtp.Connect()
            smtp.Authenticate("billing@example.com", "secret")
            smtp.SendMessage(msg)
        End Using
    End Sub

End Module