如何使用Click Once构建单个实例应用程序？

我需要一个单实例应用程序(根据这个答案),但它需要通过点击一次部署.

问题是我要求点击一次不会自动检测更新,尝试在应用程序运行时加载新版本.如果它正在运行,那么我需要激活另一个实例.通常,在选择Click Once链接时,它首先要做的是尝试查找更新.我想拦截这个并在启动正常更新过程之前检查已经运行的实例.

有谁知道在Click Once部署方案中这是如何实现的？

为了解决这个问题,我们构建了一个原型应用程序,它具有以下两个功能.

一台PC上的多个实例被禁用.通过clickonce部署单实例应用程序.当用户尝试启动应用程序的第二个实例时,将弹出一条消息,指示"另一个实例已在运行".

异步检查更新,并安装更新(如果存在).如果用户运行新实例时有可用更新,则会弹出一条消息:"可以使用更新".

构建演示应用程序的过程如下:

步骤1:使用Mutex类检测活动实例应用程序.

namespace ClickOnceDemo
{
    static class Program
    {
        /// summary>
        /// The main entry point for the application.
        /// /summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault( false );
            bool ok;
            var m = new System.Threading.Mutex( true, "Application", out ok );
            if ( !ok )
            {
                MessageBox.Show( "Another instance is already running.", ApplicationDeployment.CurrentDeployment.CurrentVersion.ToString() );
                return;
            }
           Application.Run( new UpdateProgress() );
        }
    }
}

第2步:以编程方式处理更新

在我们这样做之前,我们应该禁用自动ClickOnce更新检查(在Publish - Updates ...对话框中).

然后我们创建两个表单:UpdateProgress和mainForm,其中UpdateProgress表示下载进度,mainForm表示主应用程序.

当用户运行应用程序时,将首先启动updateProgress以检查更新.更新完成后,mainForm将启动并且updateProgress将被隐藏.

namespace ClickOnceDemo
{
public partial class UpdateProgress : Form
 {
  public UpdateProgress()
        {
            InitializeComponent();
            Text = "Checking for updates...";

            ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
            ad.CheckForUpdateCompleted += OnCheckForUpdateCompleted;
            ad.CheckForUpdateProgressChanged += OnCheckForUpdateProgressChanged;

            ad.CheckForUpdateAsync();
       }

        private void OnCheckForUpdateProgressChanged(object sender, DeploymentProgressChangedEventArgs e)
        {
            lblStatus.Text = String.Format( "Downloading: {0}. {1:D}K of {2:D}K downloaded.", GetProgressString( e.State ), e.BytesCompleted / 1024, e.BytesTotal / 1024 );
            progressBar1.Value = e.ProgressPercentage;
        }

        string GetProgressString( DeploymentProgressState state )
        {
            if ( state == DeploymentProgressState.DownloadingApplicationFiles )
            {
                return "application files";
            }
            if ( state == DeploymentProgressState.DownloadingApplicationInformation )
            {
                return "application manifest";
            }
            return "deployment manifest";
        }

        private void OnCheckForUpdateCompleted(object sender, CheckForUpdateCompletedEventArgs e)
        {
            if ( e.Error != null )
            {
                MessageBox.Show( "ERROR: Could not retrieve new version of the application. Reason: \n" + e.Error.Message + "\nPlease report this error to the system administrator." );
                return;
            }
            if ( e.Cancelled )
            {
                MessageBox.Show( "The update was cancelled." );
            }

            // Ask the user if they would like to update the application now.
            if ( e.UpdateAvailable )
            {
                if ( !e.IsUpdateRequired )
                {
                    long updateSize = e.UpdateSizeBytes;
                    DialogResult dr = MessageBox.Show( string.Format("An update ({0}K) is available. Would you like to update the application now?", updateSize/1024), "Update Available", MessageBoxButtons.OKCancel );
                    if ( DialogResult.OK == dr )
                    {
                        BeginUpdate();
                    }
                }
                else
                {
                    MessageBox.Show( "A mandatory update is available for your application. We will install the update now, after which we will save all of your in-progress data and restart your application." );
                    BeginUpdate();
                }
            }
            else
            {
                ShowMainForm();
            }
        }

        // Show the main application form
        private void ShowMainForm()
        {
            MainForm mainForm = new MainForm ();
            mainForm.Show();
            Hide();
        }

        private void BeginUpdate()
        {
            Text = "Downloading update...";
            ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
            ad.UpdateCompleted += ad_UpdateCompleted;
            ad.UpdateProgressChanged += ad_UpdateProgressChanged;

            ad.UpdateAsync();
        }

        void ad_UpdateProgressChanged( object sender, DeploymentProgressChangedEventArgs e )
        {
            String progressText = String.Format( "{0:D}K out of {1:D}K downloaded - {2:D}% complete", e.BytesCompleted / 1024, e.BytesTotal / 1024, e.ProgressPercentage );
            progressBar1.Value = e.ProgressPercentage;
            lblStatus.Text = progressText;
        }

        void ad_UpdateCompleted( object sender, AsyncCompletedEventArgs e )
        {
            if ( e.Cancelled )
            {
                MessageBox.Show( "The update of the application's latest version was cancelled." );
                return;
            }
            if ( e.Error != null )
            {
                MessageBox.Show( "ERROR: Could not install the latest version of the application. Reason: \n" + e.Error.Message + "\nPlease report this error to the system administrator." );
                return;
            }

            DialogResult dr = MessageBox.Show( "The application has been updated. Restart? (If you do not restart now, the new version will not take effect until after you quit and launch the application again.)", "Restart Application", MessageBoxButtons.OKCancel );
            if ( DialogResult.OK == dr )
            {
                Application.Restart();
            }
            else
            {
                ShowMainForm();
            }
        }
    }
}

该应用程序运行良好,我们希望它是一个很好的解决方案.
特别感谢Timothy Walters提供的源代码

当然 - 您可以禁用自动ClickOnce更新检查(在"发布" - >"更新..."对话框中),然后使用System.Deployment.Application命名空间中的对象和命令以实用方式检查更新.

查看:

System.Deployment.Application.ApplicationDeployment.CheckForUpdate()

System.Deployment.Application.ApplicationDeployment.CheckForUpdateAsync()

如果有更新,您可以在实际更新之前通过调用以下方式执行单实例应用程序检查:

System.Deployment.Application.ApplicationDeployment.Update()

System.Deployment.Application.ApplicationDeployment.UpdateAsync()