IronXLを使用してBlazorで Excel ファイルをエクスポートする方法

window.downloadFileFromStream = async (fileName, contentStreamReference) => {
    const arrayBuffer = await contentStreamReference.arrayBuffer();
    const blob = new Blob([arrayBuffer]);
    const url = URL.createObjectURL(blob);
    const anchorElement = document.createElement('a');
    anchorElement.href = url;
    anchorElement.download = fileName ?? 'export.xlsx';
    anchorElement.click();
    anchorElement.remove();
    URL.revokeObjectURL(url);
}

<script src="~/excelExport.js"></script>

using IronXL;
using System.IO;
using ExportExcel.Models;

public class ExcelExportService
{
    public byte[] GenerateSalesReport(List<SalesData> salesData)
    {
        var workbook = WorkBook.Create(ExcelFileFormat.XLSX);
        workbook.Metadata.Author = "Sales Department";

        var worksheet = workbook.CreateWorkSheet("Monthly Sales");

        // Add column headers
        worksheet["A1"].Value = "Date";
        worksheet["B1"].Value = "Product";
        worksheet["C1"].Value = "Quantity";
        worksheet["D1"].Value = "Revenue";
        worksheet["E1"].Value = "Profit Margin";

        // Style the header row
        var headerRange = worksheet["A1:E1"];
        headerRange.Style.Font.Bold = true;
        headerRange.Style.BackgroundColor = "#4472C4";
        headerRange.Style.Font.Color = "#FFFFFF";

        // Populate data rows
        int row = 2;
        foreach (var sale in salesData)
        {
            worksheet[$"A{row}"].Value = sale.Date.ToString("yyyy-MM-dd");
            worksheet[$"B{row}"].Value = sale.Product ?? "Unknown";
            worksheet[$"C{row}"].Value = sale.Quantity;
            worksheet[$"D{row}"].Value = sale.Revenue;
            worksheet[$"E{row}"].Value = $"=D{row}*0.15";
            row++;
        }

        worksheet.AutoSizeColumn(0, true);

        using var ms = workbook.ToStream();
        return ms.ToArray();
    }
}

Imports IronXL
Imports System.IO
Imports ExportExcel.Models

Public Class ExcelExportService
    Public Function GenerateSalesReport(salesData As List(Of SalesData)) As Byte()
        Dim workbook = WorkBook.Create(ExcelFileFormat.XLSX)
        workbook.Metadata.Author = "Sales Department"

        Dim worksheet = workbook.CreateWorkSheet("Monthly Sales")

        ' Add column headers
        worksheet("A1").Value = "Date"
        worksheet("B1").Value = "Product"
        worksheet("C1").Value = "Quantity"
        worksheet("D1").Value = "Revenue"
        worksheet("E1").Value = "Profit Margin"

        ' Style the header row
        Dim headerRange = worksheet("A1:E1")
        headerRange.Style.Font.Bold = True
        headerRange.Style.BackgroundColor = "#4472C4"
        headerRange.Style.Font.Color = "#FFFFFF"

        ' Populate data rows
        Dim row As Integer = 2
        For Each sale In salesData
            worksheet($"A{row}").Value = sale.Date.ToString("yyyy-MM-dd")
            worksheet($"B{row}").Value = If(sale.Product, "Unknown")
            worksheet($"C{row}").Value = sale.Quantity
            worksheet($"D{row}").Value = sale.Revenue
            worksheet($"E{row}").Value = $"=D{row}*0.15"
            row += 1
        Next

        worksheet.AutoSizeColumn(0, True)

        Using ms = workbook.ToStream()
            Return ms.ToArray()
        End Using
    End Function
End Class

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddScoped<ExcelExportService>();

var app = builder.Build();
app.MapBlazorHub();
app.MapFallbackToPage("/_Host");
app.Run();

Imports Microsoft.AspNetCore.Builder
Imports Microsoft.Extensions.DependencyInjection

Dim builder = WebApplication.CreateBuilder(args)

builder.Services.AddRazorPages()
builder.Services.AddServerSideBlazor()
builder.Services.AddScoped(Of ExcelExportService)()

Dim app = builder.Build()
app.MapBlazorHub()
app.MapFallbackToPage("/_Host")
app.Run()

@page "/excel-export"
@using ExportExcel.Models
@inject ExcelExportService ExcelService
@inject IJSRuntime JS

<h3>Excel Export Dashboard</h3>

<div class="export-section">
    <button class="btn btn-primary" @onclick="ExportSalesReport" disabled="@isExporting">
        @if (isExporting)
        {
            <span>Generating...</span>
        }
        else
        {
            <span>Export Sales Report</span>
        }
    </button>

    @if (!string.IsNullOrEmpty(errorMessage))
    {
        <div class="alert alert-danger mt-2">@errorMessage</div>
    }
</div>

@code {
    private bool isExporting = false;
    private string errorMessage = "";

    private async Task ExportSalesReport()
    {
        try
        {
            isExporting = true;
            errorMessage = "";

            var salesData = GetSalesData();
            var fileBytes = ExcelService.GenerateSalesReport(salesData);

            using var stream = new MemoryStream(fileBytes);
            using var streamRef = new DotNetStreamReference(stream);
            await JS.InvokeVoidAsync(
                "downloadFileFromStream",
                $"SalesReport_{DateTime.Now:yyyyMMdd}.xlsx",
                streamRef
            );
        }
        catch (Exception)
        {
            errorMessage = "Export failed. Please try again.";
        }
        finally
        {
            isExporting = false;
        }
    }

    private List<SalesData> GetSalesData()
    {
        return new List<SalesData>
        {
            new() { Date = DateTime.Now, Product = "Widget A", Quantity = 100, Revenue = 5000 },
            new() { Date = DateTime.Now.AddDays(-1), Product = "Widget B", Quantity = 75, Revenue = 3750 }
        };
    }
}

Imports ExportExcel.Models
Imports Microsoft.JSInterop

@page "/excel-export"

@inject ExcelExportService ExcelService
@inject IJSRuntime JS

<h3>Excel Export Dashboard</h3>

<div class="export-section">
    <button class="btn btn-primary" @onclick="ExportSalesReport" disabled="@isExporting">
        @If isExporting Then
            <span>Generating...</span>
        Else
            <span>Export Sales Report</span>
        End If
    </button>

    @If Not String.IsNullOrEmpty(errorMessage) Then
        <div class="alert alert-danger mt-2">@errorMessage</div>
    End If
</div>

@code {
    Private isExporting As Boolean = False
    Private errorMessage As String = ""

    Private Async Function ExportSalesReport() As Task
        Try
            isExporting = True
            errorMessage = ""

            Dim salesData = GetSalesData()
            Dim fileBytes = ExcelService.GenerateSalesReport(salesData)

            Using stream As New MemoryStream(fileBytes)
                Using streamRef As New DotNetStreamReference(stream)
                    Await JS.InvokeVoidAsync(
                        "downloadFileFromStream",
                        $"SalesReport_{DateTime.Now:yyyyMMdd}.xlsx",
                        streamRef
                    )
                End Using
            End Using
        Catch ex As Exception
            errorMessage = "Export failed. Please try again."
        Finally
            isExporting = False
        End Try
    End Function

    Private Function GetSalesData() As List(Of SalesData)
        Return New List(Of SalesData) From {
            New SalesData() With {.Date = DateTime.Now, .Product = "Widget A", .Quantity = 100, .Revenue = 5000},
            New SalesData() With {.Date = DateTime.Now.AddDays(-1), .Product = "Widget B", .Quantity = 75, .Revenue = 3750}
        }
    End Function
}

using IronXL;
using ExportExcel.Models;
using System.IO;

public class InventoryExportService
{
    public byte[] GenerateInventoryReport(List<InventoryItem> items)
    {
        var workbook = WorkBook.Create();
        var details = workbook.CreateWorkSheet("Inventory Details");

        // Column headers
        details["A1"].Value = "SKU";
        details["B1"].Value = "Name";
        details["C1"].Value = "Quantity";
        details["D1"].Value = "Reorder Level";
        details["E1"].Value = "Status";

        var headerRange = details["A1:E1"];
        headerRange.Style.Font.Bold = true;
        headerRange.Style.BackgroundColor = "#2E75B6";
        headerRange.Style.Font.Color = "#FFFFFF";

        for (int i = 0; i < items.Count; i++)
        {
            int row = i + 2;
            var item = items[i];

            details[$"A{row}"].Value = item.SKU;
            details[$"B{row}"].Value = item.Name;
            details[$"C{row}"].Value = item.Quantity;
            details[$"D{row}"].Value = item.ReorderLevel;
            details[$"E{row}"].Value = item.Quantity < item.ReorderLevel
                ? "Reorder Required"
                : "OK";

            if (item.Quantity < item.ReorderLevel)
            {
                // Highlight the entire row for low-stock items
                details[$"A{row}:E{row}"].Style.BackgroundColor = "#FFB6B6";
                details[$"C{row}"].Style.Font.Bold = true;
            }
        }

        details.AutoSizeColumn(0, true);
        details.AutoSizeColumn(1, true);

        using var stream = workbook.ToStream();
        return stream.ToArray();
    }
}

Imports IronXL
Imports ExportExcel.Models
Imports System.IO

Public Class InventoryExportService
    Public Function GenerateInventoryReport(items As List(Of InventoryItem)) As Byte()
        Dim workbook = WorkBook.Create()
        Dim details = workbook.CreateWorkSheet("Inventory Details")

        ' Column headers
        details("A1").Value = "SKU"
        details("B1").Value = "Name"
        details("C1").Value = "Quantity"
        details("D1").Value = "Reorder Level"
        details("E1").Value = "Status"

        Dim headerRange = details("A1:E1")
        headerRange.Style.Font.Bold = True
        headerRange.Style.BackgroundColor = "#2E75B6"
        headerRange.Style.Font.Color = "#FFFFFF"

        For i As Integer = 0 To items.Count - 1
            Dim row As Integer = i + 2
            Dim item = items(i)

            details($"A{row}").Value = item.SKU
            details($"B{row}").Value = item.Name
            details($"C{row}").Value = item.Quantity
            details($"D{row}").Value = item.ReorderLevel
            details($"E{row}").Value = If(item.Quantity < item.ReorderLevel, "Reorder Required", "OK")

            If item.Quantity < item.ReorderLevel Then
                ' Highlight the entire row for low-stock items
                details($"A{row}:E{row}").Style.BackgroundColor = "#FFB6B6"
                details($"C{row}").Style.Font.Bold = True
            End If
        Next

        details.AutoSizeColumn(0, True)
        details.AutoSizeColumn(1, True)

        Using stream = workbook.ToStream()
            Return stream.ToArray()
        End Using
    End Function
End Class

public byte[] GenerateMultiSheetReport(
    List<SalesData> sales,
    List<InventoryItem> inventory)
{
    var workbook = WorkBook.Create(ExcelFileFormat.XLSX);

    // Sheet 1 -- Sales summary
    var salesSheet = workbook.CreateWorkSheet("Sales");
    salesSheet["A1"].Value = "Date";
    salesSheet["B1"].Value = "Revenue";
    salesSheet["A1:B1"].Style.Font.Bold = true;

    for (int i = 0; i < sales.Count; i++)
    {
        salesSheet[$"A{i + 2}"].Value = sales[i].Date.ToString("yyyy-MM-dd");
        salesSheet[$"B{i + 2}"].Value = sales[i].Revenue;
    }

    // Sheet 2 -- Inventory snapshot
    var invSheet = workbook.CreateWorkSheet("Inventory");
    invSheet["A1"].Value = "SKU";
    invSheet["B1"].Value = "Name";
    invSheet["C1"].Value = "Quantity";
    invSheet["A1:C1"].Style.Font.Bold = true;

    for (int i = 0; i < inventory.Count; i++)
    {
        invSheet[$"A{i + 2}"].Value = inventory[i].SKU;
        invSheet[$"B{i + 2}"].Value = inventory[i].Name;
        invSheet[$"C{i + 2}"].Value = inventory[i].Quantity;
    }

    using var stream = workbook.ToStream();
    return stream.ToArray();
}

Public Function GenerateMultiSheetReport( _
    sales As List(Of SalesData), _
    inventory As List(Of InventoryItem)) As Byte()

    Dim workbook = WorkBook.Create(ExcelFileFormat.XLSX)

    ' Sheet 1 -- Sales summary
    Dim salesSheet = workbook.CreateWorkSheet("Sales")
    salesSheet("A1").Value = "Date"
    salesSheet("B1").Value = "Revenue"
    salesSheet("A1:B1").Style.Font.Bold = True

    For i As Integer = 0 To sales.Count - 1
        salesSheet($"A{i + 2}").Value = sales(i).Date.ToString("yyyy-MM-dd")
        salesSheet($"B{i + 2}").Value = sales(i).Revenue
    Next

    ' Sheet 2 -- Inventory snapshot
    Dim invSheet = workbook.CreateWorkSheet("Inventory")
    invSheet("A1").Value = "SKU"
    invSheet("B1").Value = "Name"
    invSheet("C1").Value = "Quantity"
    invSheet("A1:C1").Style.Font.Bold = True

    For i As Integer = 0 To inventory.Count - 1
        invSheet($"A{i + 2}").Value = inventory(i).SKU
        invSheet($"B{i + 2}").Value = inventory(i).Name
        invSheet($"C{i + 2}").Value = inventory(i).Quantity
    Next

    Using stream = workbook.ToStream()
        Return stream.ToArray()
    End Using
End Function

// Aggregate formulas on a summary row
worksheet["E2"].Value = "=SUM(D2:D100)";
worksheet["F2"].Value = "=AVERAGE(C2:C100)";
worksheet["G2"].Value = "=COUNTIF(B2:B100,\"Widget A\")";

// Named ranges improve formula readability
worksheet["D2:D100"].Name = "RevenueColumn";
worksheet["E2"].Value = "=SUM(RevenueColumn)";

// Number and date formatting prevents type misinterpretation
worksheet["D2"].Value = 12345.67m;
worksheet["D2"].FormatString = "#,##0.00";
worksheet["A2"].Value = DateTime.Now;
worksheet["A2"].FormatString = "dd/MM/yyyy";

' Aggregate formulas on a summary row
worksheet("E2").Value = "=SUM(D2:D100)"
worksheet("F2").Value = "=AVERAGE(C2:C100)"
worksheet("G2").Value = "=COUNTIF(B2:B100,""Widget A"")"

' Named ranges improve formula readability
worksheet("D2:D100").Name = "RevenueColumn"
worksheet("E2").Value = "=SUM(RevenueColumn)"

' Number and date formatting prevents type misinterpretation
worksheet("D2").Value = 12345.67D
worksheet("D2").FormatString = "#,##0.00"
worksheet("A2").Value = DateTime.Now
worksheet("A2").FormatString = "dd/MM/yyyy"

// Export as CSV for systems that consume flat files
workbook.SaveAs("report.csv");

// Or stream as CSV for download
using var ms = workbook.ToStream(ExcelFileFormat.CSV);

' Export as CSV for systems that consume flat files
workbook.SaveAs("report.csv")

' Or stream as CSV for download
Using ms As Stream = workbook.ToStream(ExcelFileFormat.CSV)
End Using