HTTP post file from .NET Core new HTTP client

Now with .NET Core 3, Microsoft released a new .NET Core HTTP client. Reference: https://docs.microsoft.com/en-us/aspnet/core/fundamentals/http-requests?view=aspnetcore-3.1 With the new client, to call a WEB API is much easier. For example, to make an HTTP GET request: var client = new HttpClinet(); var request = new HttpRequestMessage(HttpMethod.Get, url) {  …