consume webapi in winfor

System.net.Htp
private async void Method(){
var httpCleint = new HttpClient();
client.BaseAddress = new Uri("Url");
HttpResponseMessage response = await client.GetAsync("api/controller")
string result = await response.Content.ReadAsStringAsync();
}

https://docs.microsoft.com/en-us/aspnet/web-api/overview/advanced/calling-a-web-api-from-a-net-client