Asynchronous streams

Context: Asynchronous streams (C# 8.0) allow you to produce and consume sequences of data asynchronously using IAsyncEnumerable<T> and await foreach.

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

public class DataProducer
{
    public async IAsyncEnumerable<int> GetDataAsync()
    {
        for (int i = 0; i < 10; i++)
        {
            await Task.Delay(100);
            yield return i;
        }
    }
}

// Consumer
public class Program
{
    public static async Task Main()
    {
        var producer = new DataProducer();
        await foreach (var item in producer.GetDataAsync())
        {
            Console.WriteLine(item);
        }
    }
}

Real-world usage example

Reading large files line by line: Process each line asynchronously without loading the entire file.

Example: System.IO.Stream can be wrapped in an async stream.

Related sections

• 9.4.1 IAsyncEnumerable
• 9.4.2 await foreach
• 9.4.3 await using asynchronous disposable