C# clickatell to send SMS HTTP GET request

Question

I want to send a simple message using the service Clickatell.

I don't want to read the response, it will be simple GET request to send a message.

The service provides the request looks like:

https://platform.clickatell.com/messages/http/send?apiKey=xxxxxxxxxxxxxxxx==&to=xxxxxxxxxxx&content=Test+message+text

I checked it with curl

curl "https://platform.clickatell.com/messages/http/send?apiKey=apiKEY==&to=NUMBER&content=Test+message+text"

and it's working really fine.

I try to use it with my Windows Forms application with HTTP request Below is the code which I provided:

var client2 = new HttpClient();
client2.GetAsync("https://platform.clickatell.com/messages/http/send?apiKey=apiKEY==&to=NUMBER&content=Test+message+text");
App.Write("SMS SEND!");

I have info that SMS send, but I didn't receive it. My friend use my code in the .NET application and it's working for him.

Do I miss something?

Maybe it's really worth to mention I need to add to References manually using System.Net.Http;

EDIT:

I tried to add to do it async, so I edit my code to:

   static void sendSMS()
        {
            var client2 = new HttpClient();
            var task = client2.GetAsync("https://platform.clickatell.com/messages/http/send?apiKey=API_KEY==&to=MY_NUMBER&content=Test+message+text");
            task.Wait();
            App.Write("SMS SEND!");
        }

But now the SMS SEND message in the application is not shown.

Answer 1

Ok I know You use .NET 4.5 and You probably have problem with a exeption

"The underlying connection was closed: An unexpected error occurred on a send"

The right code it looks like this: (You must add 'SecurityProtocol 'before reqeust):

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;

var client2 = new HttpClient(); client2.GetAsync("https://platform.clickatell.com/messages/http/send?apiKey=apiKEY==&to=NUMBER&content=Test+message+text").Result;

More details here https://stackoverflow.com/a/32789483/5816153