[C#/TPL/.NET5] Task 클래스 : Delay 정적 메소드를 사용해 재시도시 지연 시간 증가시키기

using System;
using System.Net.Http;
using System.Threading.Tasks;

#region 문자열 다운로드하기 (비동기) - DownloadStringAsync(httpClient, uri)

/// <summary>
/// 문자열 다운로드하기 (비동기)
/// </summary>
/// <param name="httpClient">HTTP 클라이언트</param>
/// <param name="uri">URI</param>
/// <returns>문자열 태스크</returns>
public async Task<string> DownloadStringAsync(HttpClient httpClient, string uri)
{
    TimeSpan delayTimeSpan = TimeSpan.FromSeconds(1);

    for(int i = 0; i < 3; i++)
    {
        try
        {
            return await httpClient.GetStringAsync(uri);
        }
        catch
        {
        }

        await Task.Delay(delayTimeSpan);

        delayTimeSpan = delayTimeSpan + delayTimeSpan;
    }

    return await httpClient.GetStringAsync(uri);
}

#endregion