Spreadsheet Merger – Merge Any Document Type into One Excel Workbook

using Sheetize;

var loadOptions = new LoadOptions(); // common load options for all sources
var saveOptions = new SpreadsheetSaveOptions
{
OutputFile = @"C:\Results\MasterReport.xlsx"
};

SpreadsheetMerger.Process(loadOptions, saveOptions, new[]
{
@"C:\Inputs\Sales_Q1.xlsx",
@"C:\Inputs\Inventory.csv",
@"C:\Inputs\ProductCatalog.html",
@"C:\Inputs\LegacyData.xls",
@"C:\Inputs\Metadata.json"
});

using Sheetize;
using System;
using System.IO;
using System.Linq;

try
{
// 1️⃣ License activation
var license = new Sheetize.License();
license.SetLicense(@"C:\Licenses\Sheetize.SpreadsheetMerger_for_.NET.lic");

// 2️⃣ Paths
string[] sources = {
@"C:\Data\Quarter1.xlsx",
@"C:\Data\Customers.csv",
@"C:\Data\Catalog.html"
};
string outputPath = @"C:\Data\CombinedReport.xlsb";

// 3️⃣ Supported extensions
var inputExts = new[]
{
".xlsx",".xlsb",".xlsm",".xltm",".xlam",".xls",".xml",
".csv",".tsv",".sqlscript",".dif",".epub",".azw3",
".html",".mhtml",".json"
};
var outputExts = new[]
{
".xlsx",".xlsb",".xlsm",".xltm",".xlam",
".xls",".xml",".xlt",".html",".mhtml"
};

// 4️⃣ Validate output type
if (!outputExts.Contains(Path.GetExtension(outputPath).ToLower()))
throw new InvalidOperationException("Output file must be a supported spreadsheet type.");

// 5️⃣ Validate each source
foreach (var src in sources)
{
if (!File.Exists(src))
throw new FileNotFoundException($"Source not found: {src}");
if (!inputExts.Contains(Path.GetExtension(src).ToLower()))
throw new NotSupportedException($"Unsupported source type: {src}");
}

// 6️⃣ Build options
var loadOpts = new LoadOptions(); // can be customized (e.g., password, sheet filters)
var saveOpts = new SpreadsheetSaveOptions { OutputFile = outputPath };

// 7️⃣ Execute merge
SpreadsheetMerger.Process(loadOpts, saveOpts, sources);
Console.WriteLine($"✅ Merge succeeded – file saved to {outputPath}");
}
catch (Exception ex)
{
// Centralised error logging (Serilog, NLog, Application Insights, etc.)
Console.Error.WriteLine($"❌ Merge failed: {ex.GetType().Name} – {ex.Message}");
// Optionally re‑throw for upstream handling
// throw;
}

# 1️⃣ Install the NuGet package
dotnet add package Sheetize

# 2️⃣ Grab a free trial licence (no credit‑card required)
# https://purchase.sheetize.com/temp-license/113911

# 3️⃣ Place the .lic file in your project, e.g. ./Licenses/Sheetize.SpreadsheetMerger_for_.NET.lic

# 4️⃣ Use the sample code above – compile, run, and watch your master spreadsheet appear!