windows8開發-使用背景工作執行緒與更新UI

使用TheadPool以及CoreDispatcher可以實現使用背景工作執行緒與更新UI的功能。

其中CoreDispatcher應當在UI線程中擷取，並在背景工作執行緒的callback函數中使用；否則CoreDispatcher是擷取不到的。

不過win8中建議是使用Task來代替TheadPool，因為它提供了一些比較實用的介面，例如取消背景工作執行緒中的任務等。

using System;using System.Collections.Generic;using System.IO;using Windows.UI.Xaml;using Windows.System.Threading;using System.Threading.Tasks;using Windows.UI.Core;using Windows.Foundation;// 封裝了HttpPostRequestusing MyProject.HttpPost;namespace HttpTest{    /// <summary>    /// 系統管理使用者登陸退出    /// </summary>    public class AccountServer    {        // 用於調起UI線程        private Window m_CurWindow;        private CoreDispatcher m_CurCoreDispatcher;        // 登陸操作處理完成        public EventHandler<LoginCompletedEventArgs> LoginCompleted;        #region Constructor        public AccountServer()        {            m_CurWindow = Window.Current;        }        #endregion        #region Public Methods        /// <summary>        /// 使用者登陸        /// </summary>        /// <param name="userName">使用者名稱</param>        /// <param name="pwd">使用者密碼</param>        public void Login(string userName, string pwd)        {                       m_CurCoreDispatcher = m_CurWindow.Dispatcher;            ThreadPool.RunAsync(AsyncRequestLogin);        }        #region Private Methods        private HttpPostRequest HttpPostRequestInstance        {            get            {                if (null == m_HttpPostRequest)                {                    m_HttpPostRequest = new HttpPostRequest();                }                return m_HttpPostRequest;            }        }        private void AsyncRequestLogin(object state)        {            HttpPostRequestInstance.AsyncRequest(LoginUrl, HttpPostParam.PrepareLoginParams(m_UserName, m_Pwd), AsyncLoginCallback);        }        private void AsyncLoginCallback(string msg)        {                       if (string.Empty == msg)            {                NotifyLoginCompletedEvent(new LoginCompletedEventArgs(false,false));            }            else            {                HttpPostResult res = new HttpPostResult(msg);                long error = res.GetErrorCode();                if (error == HttpPostResult.NoneError)                {                    Account account = res.GetAccount();                    account.IsLogging = true;                    account.Password = m_Pwd;                    NotifyLoginCompletedEvent(new LoginCompletedEventArgs(true, account));                }                else                {                    NotifyLoginCompletedEvent(new LoginCompletedEventArgs(false));                }            }        }        private void NotifyLoginCompletedEvent(LoginCompletedEventArgs args)        {            m_CurCoreDispatcher.RunAsync(CoreDispatcherPriority.High,() =>                {                    if (LoginCompleted != null)                        LoginCompleted(this, args);                });        }        #endregion    }}