Too Long; Didn't Read
Microsoft Excel XLSX and text-based CSV (comma-separated values) are common file formats for data interchange, and applications can significantly benefit from implementing support for reading and writing these file formats. In this example, we will download the latest monthly Bitcoin-US Dollar market data in CSV format and then import that CSV data into a C# Web Service Application (which can work cross-platform) that generates a new XLSX spreadsheet containing the data in a table with a chart and some trendlines to analyze moving averages. The web application will then return the XLSX spreadsheet, which can be opened in any spreadsheet application that reads standard Open Object XML (OOXML) spreadsheet files.