C# 和 WUAPI : BeginDownload function

Question

首先，我没有任何面向对象编程的经验。我在学校创建了我的 VB 脚本和一些 Java，仅此而已。所以我的问题很可能就在那里。但是尽管如此，在过去的几天里，我一直在尝试整合一个小应用程序，让我可以扫描、选择和安装 Windows 更新。到目前为止，借助互联网上的一些帖子，我已经能够理解大部分引用资料，现在我可以选择和下载更新。

到目前为止，我已经能够使用以下代码下载一组更新:

UpdateCollection CurrentInstallCollection = (UpdateCollection)e.Argument;
UpdateDownloader CurrentDownloader = CurrentSession.CreateUpdateDownloader();
CurrentDownloader.Updates = CurrentInstallCollection;

这在后台工作程序中运行，并在下载完成后返回。它工作得很好，我可以看到更新正在文件系统上下载，但实际上没有办法在应用程序中显示进度。要做到这一点，IDownloadJob 接口(interface)允许我使用下载器的 .BeginDownload 方法。

UpdateSession.CreateUpdateDownloader 我认为，至少。问题来了:我现在已经尝试了大约 6 个小时来让代码正常工作，但无论我尝试什么都没有效果。此外，互联网上没有太多关于 .BeginDownload 方法的信息(或者至少看起来是这样)，但我对该方法的调用不起作用:

IDownloadJob CurrentDownloadJob = CurrentDownloader.BeginDownload();

我不知道要提供什么论据。我试过方法、对象……都无济于事。完整的代码块如下所示:

UpdateCollection CurrentInstallCollection = (UpdateCollection)e.Argument;
UpdateDownloader CurrentDownloader = CurrentSession.CreateUpdateDownloader();
CurrentDownloader.Updates = CurrentInstallCollection;
IDownloadJob CurrentDownloadJob = CurrentDownloader.BeginDownload();
IDownloadProgress CurrentJobProgess = CurrentDownloadJob.GetProgress();
tbStatus.Text = Convert.ToString(CurrentJobProgess.PercentComplete);

我在 Internet 上找到了一个使用 .BeginDownload(this, this, this) 调用该方法的资源，它不会在代码编辑器中报告任何错误，但可能无济于事根据我的理解，报告提供的参数是在描述的事件发生时调用的方法(进度已更改或下载已完成)。

我也试过这个，但也没用:

http://social.msdn.microsoft.com/Forums/en/csharpgeneral/thread/636a8399-2bc1-46ff-94df-a58cebfe688c

BeginDownload方法的详细说明:

http://msdn.microsoft.com/en-us/library/aa386132(v=VS.85).aspx

WUAPI 引用:

不幸的是，我不允许发布链接，但指向 BeginDownload 方法的链接指向同一个地方。

我知道，这个问题有点多，但如果有人能为我指出正确的方向(比如传递哪些参数以及如何传递)，我将不胜感激。

Answer 1

在我看来，Windows Update API (WU API Lib (WUApiLib)) 没有很好的文档记录。搜索、下载和安装的所有任务的异步“开始”如下所示。它很难掌握，不幸的是，微软在此阶段没有提供任何 C# 代码示例。我希望我能帮助我的小应用程序。该代码可以稍微整理一下，它只是在这个阶段被拼凑在一起，但它达到了它的目的。您将需要一个包含四个组件的 Windows 窗体:

private System.Windows.Forms.TextBox textBox1;
private System.ComponentModel.BackgroundWorker EnableServicesWorker;
private System.Windows.Forms.Label toolStripStatusLabel2;
private System.Windows.Forms.Label toolStripStatusLabel1;

我的代码实现了从 Microsoft 网站搜索、下载和安装更新的过程的所有异步属性(抱歉太长了):

using System;
using WUApiLib;
using System.Data;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;
using System.ComponentModel;
using System.ServiceProcess;
using System.Collections.Generic;

namespace Windows_Update_Automation
{
    public partial class Form1 : Form
    {
        public UpdateSession UpdateSession;

        #region <------- Search Section ------->

        public IUpdateSearcher iUpdateSearcher;

        public ISearchJob iSearchJob;

        public UpdateCollection NewUpdatesCollection;

        public ISearchResult NewUpdatesSearchResult;

        #endregion <------- Search Section ------->

        #region <------- Downloader Section ------->

        public IUpdateDownloader iUpdateDownloader;

        public IDownloadJob iDownloadJob;

        public IDownloadResult iDownloadResult;

        #endregion <------- Downloader Section ------->

        #region <------- Installer Section ------->

        public IUpdateInstaller iUpdateInstaller;

        public IInstallationJob iInstallationJob;

        public IInstallationResult iInstallationResult;

        #endregion <------- Installer Section ------->

        // Declare a Delegate Type for Message Notification...
        public delegate void SendNotification();

        // Create an Instance of Delegate Type...
        public SendNotification sendNotification;

        private int count = 0;

        public int Count
        {
            get { return count; }
            set { count = value; }
        }

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // Show - or Hide...
            this.Show();

            // Encapsulate the setTextBox1 Method in Delegate SendNotification...
            sendNotification = new SendNotification(setTextBox1);

            // Set Text Box Value...
            this.toolStripStatusLabel1.Text = "Enabling Update Services...";

            // Set Text Box Value...
            this.toolStripStatusLabel2.Text = "";

            // Lets check Windows is up to that task...
            EnableServicesWorker.RunWorkerAsync();
        }

        private void EnableServicesWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            // Get Services Collection...
            ServiceController[] serviceController;
            serviceController = ServiceController.GetServices();

            // Loop through and check for a particular Service...
            foreach (ServiceController scTemp in serviceController)
            {
                switch (scTemp.DisplayName)
                {
                    case "Windows Update":
                        RestartService(scTemp.DisplayName, 5000);
                        break;
                    case "Automatic Updates":
                        RestartService(scTemp.DisplayName, 5000);
                        break;
                    default:
                        break;
                }
            }

            // Check for iAutomaticUpdates.ServiceEnabled...
            IAutomaticUpdates iAutomaticUpdates = new AutomaticUpdates();
            if (!iAutomaticUpdates.ServiceEnabled)
            {
                iAutomaticUpdates.EnableService();
            }
        }

        private void EnableServicesWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.toolStripStatusLabel1.Text = "Searching for updates...";

            iUpdateSearch();
        }

        public static void RestartService(string serviceName, int timeoutMilliseconds)
        {
            ServiceController serviceController = new ServiceController(serviceName);
            try
            {
                int millisec1 = Environment.TickCount;
                TimeSpan timeout = TimeSpan.FromMilliseconds(timeoutMilliseconds);

                serviceController.Stop();
                serviceController.WaitForStatus(ServiceControllerStatus.Stopped, timeout);

                // count the rest of the timeout
                int millisec2 = Environment.TickCount;
                timeout = TimeSpan.FromMilliseconds(timeoutMilliseconds - (millisec2 - millisec1));

                serviceController.Start();
                serviceController.WaitForStatus(ServiceControllerStatus.Running, timeout);
            }
            catch
            {
                // ...
            }
        }

        #region <------- Search Methods ------->

        private void iUpdateSearch()
        {
            UpdateSession = new UpdateSession();
            iUpdateSearcher = UpdateSession.CreateUpdateSearcher();

            // Only Check Online..
            iUpdateSearcher.Online = true;

            // Begin Asynchronous IUpdateSearcher...
            iSearchJob = iUpdateSearcher.BeginSearch("IsInstalled=0 AND IsPresent=0", new iUpdateSearcher_onCompleted(this), new iUpdateSearcher_state(this));
        }

        private void iUpdateSearchComplete(Form1 mainform)
        {
            Form1 formRef = mainform;

            // Declare a new UpdateCollection and populate the result...
            NewUpdatesCollection = new UpdateCollection();
            NewUpdatesSearchResult = iUpdateSearcher.EndSearch(iSearchJob);

            Count = NewUpdatesSearchResult.Updates.Count;
            formRef.Invoke(formRef.sendNotification);

            // Accept Eula code for each update
            for (int i = 0; i < NewUpdatesSearchResult.Updates.Count; i++)
            {
                IUpdate iUpdate = NewUpdatesSearchResult.Updates[i];

                if (iUpdate.EulaAccepted == false)
                {
                    iUpdate.AcceptEula();
                }

                NewUpdatesCollection.Add(iUpdate);
            }

            foreach (IUpdate update in NewUpdatesSearchResult.Updates)
            {
                textBox1.AppendText(update.Title + Environment.NewLine);
            }

            if (NewUpdatesSearchResult.Updates.Count > 0)
            {
                iUpdateDownload();
            }
        }

        #endregion <------- Search Methods ------->

        #region <------- Downloader Methods ------->

        private void iUpdateDownload()
        {
            UpdateSession = new UpdateSession();
            iUpdateDownloader = UpdateSession.CreateUpdateDownloader();

            iUpdateDownloader.Updates = NewUpdatesCollection;
            iUpdateDownloader.Priority = DownloadPriority.dpHigh;
            iDownloadJob = iUpdateDownloader.BeginDownload(new iUpdateDownloader_onProgressChanged(this), new iUpdateDownloader_onCompleted(this), new iUpdateDownloader_state(this));
        }

        public void iDownloadComplete()
        {
            iDownloadResult = iUpdateDownloader.EndDownload(iDownloadJob);
            if (iDownloadResult.ResultCode == OperationResultCode.orcSucceeded)
            {
                this.toolStripStatusLabel1.Text = "Installing Updates...";

                iInstallation();
            }
            else
            {
                string message = "The Download has failed: " + iDownloadResult.ResultCode + ". Please check your     internet connection then Re-Start the application.";
                string caption = "Download Failed!";
                MessageBoxButtons buttons = MessageBoxButtons.OK;
                MessageBoxIcon icon = MessageBoxIcon.Error;
                MessageBox.Show(message, caption, buttons, icon);

                Application.Exit();
            }
        }

        #endregion <------- Downloader Methods ------->

        #region <------- Installation Methods ------->

        public void iInstallation()
        {
            iUpdateInstaller = UpdateSession.CreateUpdateInstaller() as IUpdateInstaller;
            iUpdateInstaller.Updates = this.NewUpdatesCollection;

            iInstallationJob = iUpdateInstaller.BeginInstall(new iUpdateInstaller_onProgressChanged(this), new iUpdateInstaller_onCompleted(this), new iUpdateInstaller_state(this));
        }

        public void iInstallationComplete()
        {
            iInstallationResult = iUpdateInstaller.EndInstall(iInstallationJob);
            if (iInstallationResult.ResultCode == OperationResultCode.orcSucceeded)
            {
                this.toolStripStatusLabel1.Text = "Installation Complete...";
            }
            else
            {
                string message = "The Installation has failed: " + iInstallationResult.ResultCode + ".";
                string caption = "DownInstallationload Failed!";
                MessageBoxButtons buttons = MessageBoxButtons.OK;
                MessageBoxIcon icon = MessageBoxIcon.Error;
                MessageBox.Show(message, caption, buttons, icon);

                Application.Exit();
            }
        }

        #endregion <------- Installation Methods ------->

        #region <------- Notification Methods ------->

        public void setTextBox1()
        {
            toolStripStatusLabel1.Text = Count + " Updates found...";
        }

        public void setTextBox1Notification(string txt)
        {
            toolStripStatusLabel1.Text = txt;
        }

        public void setTextBox2Notification(string txt)
        {
            toolStripStatusLabel2.Text = txt;
        }

        #endregion <------- Notification Methods ------->

        #region <------- iUpdateSearcher.BeginDownload Object Abstract Class's ------->
        // onCompleted [in] 
        // An ISearchCompletedCallback interface that is called when an asynchronous search operation is complete.
        public class iUpdateSearcher_onCompleted : ISearchCompletedCallback
        {
            private Form1 form1;

            public iUpdateSearcher_onCompleted(Form1 mainForm)
            {
                this.form1 = mainForm;
            }

            // Implementation of IDownloadCompletedCallback interface...
            public void Invoke(ISearchJob searchJob, ISearchCompletedCallbackArgs e)
            {
                form1.iUpdateSearchComplete(this.form1);
            }
        }

        // state [in] 
        // The caller-specific state that is returned by the AsyncState property of the ISearchJob interface.
        public class iUpdateSearcher_state
        {
            private Form1 form1;

            // Implementation of state interface...
            public iUpdateSearcher_state(Form1 mainForm)
            {
                this.form1 = mainForm;

                form1.setTextBox2Notification("State: Search Started...");
            }
        }

        #endregion <------- iUpdateSearcher.BeginDownload Object Abstract Class's ------->

        #region <------- iUpdateDownloader.BeginDownload Object Abstract Class's ------->
        // onProgressChanged [in] 
        // An IDownloadProgressChangedCallback interface that is called periodically for download progress changes before download is complete.
        public class iUpdateDownloader_onProgressChanged : IDownloadProgressChangedCallback
        {
            private Form1 form1;

            public iUpdateDownloader_onProgressChanged(Form1 mainForm)
            {
                this.form1 = mainForm;
            }

            // Implementation of IDownloadProgressChangedCallback interface...
            public void Invoke(IDownloadJob downloadJob, IDownloadProgressChangedCallbackArgs e)
            {

                decimal bDownloaded = ((e.Progress.TotalBytesDownloaded / 1024) / 1024);
                decimal bToDownloaded = ((e.Progress.TotalBytesToDownload / 1024) / 1024);
                bDownloaded = decimal.Round(bDownloaded, 2);
                bToDownloaded = decimal.Round(bToDownloaded, 2);

                form1.setTextBox1Notification("Downloading Update: "
                 + e.Progress.CurrentUpdateIndex
                 + "/"
                 + downloadJob.Updates.Count
                 + " - "
                 + bDownloaded + "Mb"
                 + " / "
                 + bToDownloaded + "Mb");
            }
        }

        // onCompleted [in] 
        // An IDownloadCompletedCallback interface (C++/COM) that is called when an asynchronous download operation is complete.
        public class iUpdateDownloader_onCompleted : IDownloadCompletedCallback
        {
            private Form1 form1;

            public iUpdateDownloader_onCompleted(Form1 mainForm)
            {
                this.form1 = mainForm;
            }

            // Implementation of IDownloadCompletedCallback interface...
            public void Invoke(IDownloadJob downloadJob, IDownloadCompletedCallbackArgs e)
            {
                form1.iDownloadComplete();
            }
        }

        // state [in] 
        // The caller-specific state that the AsyncState property of the IDownloadJob interface returns. 
        // A caller may use this parameter to attach a value to the download job object. 
        // This allows the caller to retrieve custom information about that download job object at a later time.
        public class iUpdateDownloader_state
        {
            private Form1 form1;

            // Implementation of state interface...
            public iUpdateDownloader_state(Form1 mainForm)
            {
                this.form1 = mainForm;

                form1.setTextBox2Notification("State: Download Started...");
            }
        }

        #endregion <------- iUpdateDownloader.BeginDownload Objects ------->

        #region <------- iUpdateInstaller.BeginInstall Object Abstract Class's ------->
        // onProgressChanged [in] 
        // An IDownloadProgressChangedCallback interface that is called periodically for download progress changes before download is complete.
        public class iUpdateInstaller_onProgressChanged : IInstallationProgressChangedCallback
        {
            private Form1 form1;

            public iUpdateInstaller_onProgressChanged(Form1 mainForm)
            {
                this.form1 = mainForm;
            }

            // Implementation of IDownloadProgressChangedCallback interface...
            public void Invoke(IInstallationJob iInstallationJob, IInstallationProgressChangedCallbackArgs e)
            {
                form1.setTextBox1Notification("Installing Update: "
                 + e.Progress.CurrentUpdateIndex
                 + " / "
                 + iInstallationJob.Updates.Count
                 + " - "
                 + e.Progress.CurrentUpdatePercentComplete + "% Complete");
            }
        }

        // onCompleted [in] 
        // An IDownloadCompletedCallback interface (C++/COM) that is called when an asynchronous download operation is complete.
        public class iUpdateInstaller_onCompleted : IInstallationCompletedCallback
        {
            private Form1 form1;

            public iUpdateInstaller_onCompleted(Form1 mainForm)
            {
                this.form1 = mainForm;
            }

            // Implementation of IDownloadCompletedCallback interface...
            public void Invoke(IInstallationJob iInstallationJob, IInstallationCompletedCallbackArgs e)
            {
                form1.iInstallationComplete();
            }
        }

        // state [in] 
        // The caller-specific state that the AsyncState property of the IDownloadJob interface returns. 
        // A caller may use this parameter to attach a value to the download job object. 
        // This allows the caller to retrieve custom information about that download job object at a later time.
        public class iUpdateInstaller_state
        {
            private Form1 form1;

            // Implementation of state interface...
            public iUpdateInstaller_state(Form1 mainForm)
            {
                this.form1 = mainForm;

                form1.setTextBox2Notification("State: Installation Started...");
            }
        }

#endregion <------- iUpdateInstaller.BeginInstall Objects ------->