c#如何发短信

using System;
using System.Net.Http;
using System.Text;
using Newtonsoft.Json;

public class SmsSender
{
    private const string ApiUrl = "https://sms.example.com/send";
    private const stringApiKey = "your_api_key";

    public async Task SendSmsAsync(string phoneNumber, string message)
    {
        var client = new HttpClient();
        var content = new FormUrlEncodedContent(new[]
        {
            new KeyValuePair<string, string>("phone", phoneNumber),
            new KeyValuePair<string, string>("message", message),
            new KeyValuePair<string, string>("api_key", apiKey)
        });

        var response = await client.PostAsync(ApiUrl, content);
        var responseString = await response.Content.ReadAsStringAsync();

        if (response.IsSuccessStatusCode)
        {
            Console.WriteLine("短信发送成功！");
        }
        else
        {
            Console.WriteLine($"短信发送失败: {responseString}");
        }
    }
}

// 使用示例
public class Program
{
    public static async Task Main(string[] args)
    {
        var smsSender = new SmsSender();
        await smsSender.SendSmsAsync("1234567890", "Hello, this is a test message!");
    }
}