C# – Read a text file line by line

There are two simple ways to read a text file line by line: Here’s an example of using File.ReadLines() to read a file line by line in a loop: This outputs the file’s lines: Here’s an example of using File.ReadAllLines() to read the same file into a string array and then loop through it. Skip … Read more

ASP.NET Core – Receive a request with CSV data

There are two ways to receive CSV data in a web API: In this article, I’ll show examples of both of these approaches. I’ll be using the CsvHelper library to parse CSV data into model objects and then do model validation. Note: To use CsvHelper, install the CsvHelper package (Install-Package CsvHelper). Or use whichever parser … Read more

C# – Deserialize a JSON array to a list

When you’re working with a JSON array, you can deserialize it to a list like this: This deserializes all of the objects in the JSON array into a List<Movie>. You can use this list object like usual. Note: All examples will use System.Collections.Generic and System.Text.Json. I’ll exclude the using statements for brevity. Example – JSON … Read more

C# – Deserialize JSON as a stream

Here’s an example of deserializing JSON from a file as a stream with System.Text.Json: Stream deserialization has three main benefits: In this article, I’ll go into details about these benefits and show a few other stream serialization scenarios. Benefits of deserializing as a stream Performance There are two ways to deserialize JSON: Deserializing a stream … Read more

C# – How to batch read with Threading.ChannelReader

In a consumer/producer scenario, there are many reasons why you might want the consumer to read a batch of items. Maybe you’re bulk inserting into the database, or sending a payload with HttpClient. Sending lots of individual items over the network can be costly, and waiting for a full batch of items before sending is … Read more

C# – Using Channel as an async queue

The Channel class (from System.Threading.Channels) is a non-blocking async queue. It implements the producer-consumer pattern, which has two parts: Compare this with using BlockingCollection, which is a blocking concurrent queue. In this article, I’ll show how to use a Channel. 1 – Create the Channel The first step is to create the Channel object. Here’s … Read more

ASP.NET – Async SSE endpoint

Server-Sent Events (SSE) allow a client to subscribe to messages on a server. The server pushes new messages to the client as they happen. This is an alternative to the client polling the server for new messages. In this article I’ll show how to implement the messaging system shown in the diagram below. This uses … Read more