Microsoft Officeを使わずにC#でExcelファイルを開く方法

Install-Package IronXL
dotnet add package IronXL

using IronXL;

Imports IronXL

using IronXL;

// Load any Excel file -- XLSX, XLS, CSV, or TSV
WorkBook workbook = WorkBook.Load("example.xlsx");

// Access the second worksheet (zero-indexed)
WorkSheet worksheet = workbook.WorkSheets[1];

// Read a specific cell value
decimal revenue = worksheet["E2"].DecimalValue;
Console.WriteLine($"Order Total: {revenue}");

// Iterate over a range of cells
foreach (var cell in worksheet["C2:C6"])
{
    Console.WriteLine($"Product: {cell.Text}");
}

Imports IronXL

' Load any Excel file -- XLSX, XLS, CSV, or TSV
Dim workbook As WorkBook = WorkBook.Load("example.xlsx")

' Access the second worksheet (zero-indexed)
Dim worksheet As WorkSheet = workbook.WorkSheets(1)

' Read a specific cell value
Dim revenue As Decimal = worksheet("E2").DecimalValue
Console.WriteLine($"Order Total: {revenue}")

' Iterate over a range of cells
For Each cell In worksheet("C2:C6")
    Console.WriteLine($"Product: {cell.Text}")
Next

using IronXL;

WorkBook wb = WorkBook.Load(@"C:\Data\Inventory.xlsx");
WorkSheet ws = wb.GetWorkSheet("Products");

// Read different data types directly
文字列 productName = ws["A2"].StringValue;
int quantity       = ws["B2"].IntValue;
decimal price      = ws["C2"].DecimalValue;
日時 updated   = ws["D2"].日時Value;

// Use aggregate functions on ranges for performance
decimal totalStock = ws["B2:B100"].Sum();
decimal maxPrice   = ws["C2:C100"].Max();

Console.WriteLine($"Product: {productName}, Qty: {quantity}, Price: {price:C}");
Console.WriteLine($"Total stock units: {totalStock}, Highest price: {maxPrice:C}");

Imports IronXL

Dim wb As WorkBook = WorkBook.Load("C:\Data\Inventory.xlsx")
Dim ws As WorkSheet = wb.GetWorkSheet("Products")

' Read different data types directly
Dim productName As String = ws("A2").StringValue
Dim quantity As Integer = ws("B2").IntValue
Dim price As Decimal = ws("C2").DecimalValue
Dim updated As DateTime = ws("D2").DateTimeValue

' Use aggregate functions on ranges for performance
Dim totalStock As Decimal = ws("B2:B100").Sum()
Dim maxPrice As Decimal = ws("C2:C100").Max()

Console.WriteLine($"Product: {productName}, Qty: {quantity}, Price: {price:C}")
Console.WriteLine($"Total stock units: {totalStock}, Highest price: {maxPrice:C}")

using IronXL;
using System.IO;

// Validate and load the file
static List<文字列> CheckLowStock(文字列 filePath)
{
    var lowStockItems = new List<文字列>();

    if (!File.Exists(filePath))
    {
        Console.WriteLine($"File not found: {filePath}");
        return lowStockItems;
    }

    文字列 ext = Path.GetExtension(filePath).ToLower();
    if (ext is not (".xlsx" or ".xls" or ".csv"))
    {
        Console.WriteLine($"Unsupported file type: {ext}");
        return lowStockItems;
    }

    try
    {
        WorkBook workbook = WorkBook.Load(filePath);

        foreach (WorkSheet sheet in workbook.WorkSheets)
        {
            Console.WriteLine($"Checking sheet: {sheet.Name}");

            for (int row = 2; row <= sheet.RowCount; row++)
            {
                文字列 itemName  = sheet[$"A{row}"].StringValue;
                int stockLevel   = sheet[$"B{row}"].IntValue;

                if (stockLevel < 10 && !文字列.IsNullOrEmpty(itemName))
                {
                    lowStockItems.Add($"{itemName} -- {stockLevel} units ({sheet.Name})");
                }
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error reading Excel file: {ex.Message}");
    }

    return lowStockItems;
}

// Export results to a new workbook
static void ExportReport(List<文字列> items, 文字列 outputPath)
{
    WorkBook report     = WorkBook.Create();
    WorkSheet sheet     = report.CreateWorkSheet("Low Stock Report");

    sheet["A1"].Value   = "Item Description";
    sheet["B1"].Value   = "Source Sheet";

    sheet["A1:B1"].Style.Font.Bold        = true;
    sheet["A1:B1"].Style.BackgroundColor  = "#4472C4";
    sheet["A1:B1"].Style.Font.Color       = "#FFFFFF";

    int rowIndex = 2;
    foreach (文字列 item in items)
    {
        sheet[$"A{rowIndex}"].Value = item;
        rowIndex++;
    }

    report.SaveAs(outputPath);
    Console.WriteLine($"Report saved to: {outputPath}");
}

// Run
var lowStockItems = CheckLowStock("inventory.xlsx");
ExportReport(lowStockItems, "low-stock-report.xlsx");

Imports IronXL
Imports System.IO

' Validate and load the file
Private Shared Function CheckLowStock(filePath As String) As List(Of String)
    Dim lowStockItems As New List(Of String)()

    If Not File.Exists(filePath) Then
        Console.WriteLine($"File not found: {filePath}")
        Return lowStockItems
    End If

    Dim ext As String = Path.GetExtension(filePath).ToLower()
    If ext <> ".xlsx" AndAlso ext <> ".xls" AndAlso ext <> ".csv" Then
        Console.WriteLine($"Unsupported file type: {ext}")
        Return lowStockItems
    End If

    Try
        Dim workbook As WorkBook = WorkBook.Load(filePath)

        For Each sheet As WorkSheet In workbook.WorkSheets
            Console.WriteLine($"Checking sheet: {sheet.Name}")

            For row As Integer = 2 To sheet.RowCount
                Dim itemName As String = sheet($"A{row}").StringValue
                Dim stockLevel As Integer = sheet($"B{row}").IntValue

                If stockLevel < 10 AndAlso Not String.IsNullOrEmpty(itemName) Then
                    lowStockItems.Add($"{itemName} -- {stockLevel} units ({sheet.Name})")
                End If
            Next
        Next
    Catch ex As Exception
        Console.WriteLine($"Error reading Excel file: {ex.Message}")
    End Try

    Return lowStockItems
End Function

' Export results to a new workbook
Private Shared Sub ExportReport(items As List(Of String), outputPath As String)
    Dim report As WorkBook = WorkBook.Create()
    Dim sheet As WorkSheet = report.CreateWorkSheet("Low Stock Report")

    sheet("A1").Value = "Item Description"
    sheet("B1").Value = "Source Sheet"

    sheet("A1:B1").Style.Font.Bold = True
    sheet("A1:B1").Style.BackgroundColor = "#4472C4"
    sheet("A1:B1").Style.Font.Color = "#FFFFFF"

    Dim rowIndex As Integer = 2
    For Each item As String In items
        sheet($"A{rowIndex}").Value = item
        rowIndex += 1
    Next

    report.SaveAs(outputPath)
    Console.WriteLine($"Report saved to: {outputPath}")
End Sub

' Run
Dim lowStockItems As List(Of String) = CheckLowStock("inventory.xlsx")
ExportReport(lowStockItems, "low-stock-report.xlsx")

IronXL.License.LicenseKey = "YOUR-LICENSE-KEY-HERE";

Imports IronXL

IronXL.License.LicenseKey = "YOUR-LICENSE-KEY-HERE"