// 實(shí)例化HttpClient對(duì)象
HttpClient hc = new HttpClient();
// 發(fā)送Get請(qǐng)求獲取
string strContent =await hc.GetStringAsync("http://www.baidu.com");

using System.Web;
using System.Web.Mvc;

namespace HttpClientMVCTestDemo.Controllers
{
    public class LoginRequest
    {
        public string userName { get; set; }
        public string password { get; set; }
    }


    public class HttpClientTestController : Controller
    {
        // GET: HttpClientTest
        public ActionResult Index()
        {
            return View();
        }

        /// <summary>
        /// 發(fā)送表單請(qǐng)求
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        [HttpPost]
        public string Login(string userName, string password)
        {

            if (userName == "admin" && password == "123")
            {
                return "ok";
            }
            else
            {
                return "error";
            }
        }

        /// <summary>
        /// 發(fā)送Json格式的請(qǐng)求
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        [HttpPost]
        public string Login2(LoginRequest data)
        {
            string userName = data.userName;
            string password = data.password;
            if (userName == "admin" && password == "123")
            {
                return "ok";
            }
            else
            {
                return "error";
            }
        }

        /// <summary>
        /// 上傳文件
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>
        [HttpPost]
        public string Upload(HttpPostedFileBase file)
        {
            string userName = Request.Headers["UserName"];
            string password = Request.Headers["Password"];
            if (userName == "admin" && password == "123")
            {
                // 保存文件
                file.SaveAs(Server.MapPath("~/" + file.FileName));
                return "ok";
            }
            else
            {
                return "error";
            }
        }
    }
}

/// <summary>
/// 模擬發(fā)送表單內(nèi)容的Http請(qǐng)求
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void btnForm_Click(object sender, EventArgs e)
{
    // 實(shí)例化對(duì)象
    HttpClient client = new HttpClient();
    Dictionary<string, string> dic = new Dictionary<string, string>();
    dic["userName"] = "admin";
    dic["password"] = "123";
    // 參數(shù)
    FormUrlEncodedContent content = new FormUrlEncodedContent(dic);
    // 發(fā)送post請(qǐng)求
    HttpResponseMessage responseMsg = await client.PostAsync("http://localhost:55179/HttpClientTest/login", content);
    // 返回報(bào)文體
    // responseMsg.Content 
    // 返回響應(yīng)頭
    // responseMsg.Headers
    // 返回響應(yīng)碼
    // responseMsg.StatusCode
    // 獲取返回值 這里確定返回的是字符串，調(diào)用string
    string msg =await responseMsg.Content.ReadAsStringAsync();
    MessageBox.Show($"響應(yīng)碼:{responseMsg.StatusCode.ToString()}");
    MessageBox.Show($"返回內(nèi)容：{msg}");
}

/// <summary>
/// 發(fā)送json
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void btnJson_Click(object sender, EventArgs e)
{
    // json格式的字符串
    string jsonData = "{userName:'admin',password:'123'}";
    // 實(shí)例化對(duì)象
    HttpClient client = new HttpClient();
    StringContent content = new StringContent(jsonData);
    // 設(shè)置contentType，必須要設(shè)置 設(shè)置為json格式，MVC會(huì)自動(dòng)轉(zhuǎn)換成Model類型
    content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json");
    // 發(fā)送post請(qǐng)求
    HttpResponseMessage responseMsg = await client.PostAsync("http://localhost:55179/HttpClientTest/login2", content);
    // 獲取返回值
    string msg = await responseMsg.Content.ReadAsStringAsync();
    MessageBox.Show($"響應(yīng)碼:{responseMsg.StatusCode.ToString()}");
    MessageBox.Show($"返回內(nèi)容：{msg}");
}

/// <summary>
/// 上傳文件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void btnUpload_Click(object sender, EventArgs e)
{
    // 實(shí)例化對(duì)象
    HttpClient client = new HttpClient();
    MultipartFormDataContent content = new MultipartFormDataContent();
    content.Headers.Add("UserName", "admin");
    content.Headers.Add("Password", "123");
    using (Stream stream = File.OpenRead(@"F:\數(shù)據(jù)庫.txt"))
    {
        content.Add(new StreamContent(stream), "file", "test.txt");
        HttpResponseMessage responseMsg = await client.PostAsync("http://localhost:55179/HttpClientTest/Upload", content);
        // 返回值
        string msg = await responseMsg.Content.ReadAsStringAsync();
        MessageBox.Show($"響應(yīng)碼:{responseMsg.StatusCode.ToString()}");
        MessageBox.Show($"返回內(nèi)容：{msg}");
    }
}