InPlaceHostingManager.GetManifestAsync Method

Definition

Namespace:

System.Deployment.Application

Assembly:

System.Deployment.dll

Downloads the deployment manifest of the ClickOnce application in the background, and raises an event when the operation has either completed or encountered an error.

C#

public void GetManifestAsync();

Examples

The following code examples demonstrate how to call the GetManifestAsync method. The handler for the GetManifestCompleted event callback checks to see if the manifest download completed successfully, and if so, prompts the user with additional information about the application. If the user agrees to continue the installation, the handler calls DownloadApplicationAsync.

The following code examples assume that you have already defined and created an instance of InPlaceHostingManager named iphm.

C#

void iphm_GetManifestCompleted(object sender, GetManifestCompletedEventArgs e)
{
    // Check for an error.
    if (e.Error != null)
    {
        // Cancel download and install.
        MessageBox.Show("Could not download manifest. Error: " + e.Error.Message);
        return;
    }

    // bool isFullTrust = CheckForFullTrust(e.ApplicationManifest);

    // Verify this application can be installed.
    try
    {
        // the true parameter allows InPlaceHostingManager
        // to grant the permissions requested in the applicaiton manifest.
        iphm.AssertApplicationRequirements(true) ; 
    }
    catch (Exception ex)
    {
        MessageBox.Show("An error occurred while verifying the application. " +
            "Error: " + ex.Message);
        return;
    }

    // Use the information from GetManifestCompleted() to confirm 
    // that the user wants to proceed.
    string appInfo = "Application Name: " + e.ProductName;
    appInfo += "\nVersion: " + e.Version;
    appInfo += "\nSupport/Help Requests: " + (e.SupportUri != null ?
        e.SupportUri.ToString() : "N/A");
    appInfo += "\n\nConfirmed that this application can run with its requested permissions.";
    // if (isFullTrust)
    // appInfo += "\n\nThis application requires full trust in order to run.";
    appInfo += "\n\nProceed with installation?";

    DialogResult dr = MessageBox.Show(appInfo, "Confirm Application Install",
        MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
    if (dr != System.Windows.Forms.DialogResult.OK)
    {
        return;
    }

    // Download the deployment manifest. 
    iphm.DownloadProgressChanged += new EventHandler<DownloadProgressChangedEventArgs>(iphm_DownloadProgressChanged);
    iphm.DownloadApplicationCompleted += new EventHandler<DownloadApplicationCompletedEventArgs>(iphm_DownloadApplicationCompleted);

    try
    {
        // Usually this shouldn't throw an exception unless AssertApplicationRequirements() failed, 
        // or you did not call that method before calling this one.
        iphm.DownloadApplicationAsync();
    }
    catch (Exception downloadEx)
    {
        MessageBox.Show("Cannot initiate download of application. Error: " +
            downloadEx.Message);
        return;
    }
}

/*
private bool CheckForFullTrust(XmlReader appManifest)
{
    if (appManifest == null)
    {
        throw (new ArgumentNullException("appManifest cannot be null."));
    }

    XAttribute xaUnrestricted =
        XDocument.Load(appManifest)
            .Element("{urn:schemas-microsoft-com:asm.v1}assembly")
            .Element("{urn:schemas-microsoft-com:asm.v2}trustInfo")
            .Element("{urn:schemas-microsoft-com:asm.v2}security")
            .Element("{urn:schemas-microsoft-com:asm.v2}applicationRequestMinimum")
            .Element("{urn:schemas-microsoft-com:asm.v2}PermissionSet")
            .Attribute("Unrestricted"); // Attributes never have a namespace

    if (xaUnrestricted != null)
        if (xaUnrestricted.Value == "true")
            return true;

    return false;
}
*/

C#

iphm.GetManifestCompleted += new EventHandler<GetManifestCompletedEventArgs>(iphm_GetManifestCompleted);
iphm.GetManifestAsync();

Remarks

To receive notification of when this event completes, create an event handler for the GetManifestCompleted event. If this event is called, and no error is indicated by GetManifestCompletedEventArgs, you should next call AssertApplicationRequirements to verify that the application will have permission to run on the local computer.

Applies to