DownloadProgressChangedEventArgs Класс

Определение

Предоставляет данные для события DownloadProgressChanged.Provides data for the DownloadProgressChanged event.

public ref class DownloadProgressChangedEventArgs : System::ComponentModel::ProgressChangedEventArgs
public class DownloadProgressChangedEventArgs : System.ComponentModel.ProgressChangedEventArgs
type DownloadProgressChangedEventArgs = class
    inherit ProgressChangedEventArgs
Public Class DownloadProgressChangedEventArgs
Inherits ProgressChangedEventArgs
Наследование
DownloadProgressChangedEventArgs

Примеры

В следующем примере кода показано использование DownloadProgressChangedEventArgs в контексте приложения, которое использует InPlaceHostingManager для программного скачивания и установки приложения ClickOnce.The following code example demonstrates the use of DownloadProgressChangedEventArgs in the context of an application that uses InPlaceHostingManager to download and install a ClickOnce application programmatically.

InPlaceHostingManager iphm = null;

public void InstallApplication(string deployManifestUriStr)
{
    try
    {
        Uri deploymentUri = new Uri(deployManifestUriStr);
        iphm = new InPlaceHostingManager(deploymentUri, false);
    }
    catch (UriFormatException uriEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "The deployment manifest URL supplied is not a valid URL. " +
            "Error: " + uriEx.Message);
        return;
    }
    catch (PlatformNotSupportedException platformEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "This program requires Windows XP or higher. " +
            "Error: " + platformEx.Message);
        return;
    }
    catch (ArgumentException argumentEx)
    {
        MessageBox.Show("Cannot install the application: " + 
            "The deployment manifest URL supplied is not a valid URL. " +
            "Error: " + argumentEx.Message);
        return;
    }

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

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;
}
*/

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

    // Inform the user that their application is ready for use. 
    MessageBox.Show("Application installed! You may now run it from the Start menu.");
}

void iphm_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
{
    // you can show percentage of task completed using e.ProgressPercentage
}
    Dim WithEvents iphm As InPlaceHostingManager = Nothing

    Public Sub InstallApplication(ByVal deployManifestUriStr As String)
        Try
            Dim deploymentUri As New Uri(deployManifestUriStr)
            iphm = New InPlaceHostingManager(deploymentUri, False)
            MessageBox.Show("Created the object.")
        Catch uriEx As UriFormatException
            MessageBox.Show("Cannot install the application: " & _
                            "The deployment manifest URL supplied is not a valid URL." & _
                            "Error: " & uriEx.Message)
            Return
        Catch platformEx As PlatformNotSupportedException
            MessageBox.Show("Cannot install the application: " & _
                            "This program requires Windows XP or higher. " & _
                            "Error: " & platformEx.Message)
            Return
        Catch argumentEx As ArgumentException
            MessageBox.Show("Cannot install the application: " & _
                            "The deployment manifest URL supplied is not a valid URL." & _
                            "Error: " & argumentEx.Message)
            Return
        End Try

        iphm.GetManifestAsync()
    End Sub

    Private Sub iphm_GetManifestCompleted(ByVal sender As Object, ByVal e As GetManifestCompletedEventArgs) Handles iphm.GetManifestCompleted
        ' Check for an error.
        If (e.Error IsNot Nothing) Then
            ' Cancel download and install.
            MessageBox.Show("Could not download manifest. Error: " & e.Error.Message)
            Return
        End If

        ' Dim isFullTrust As Boolean = CheckForFullTrust(e.ApplicationManifest)

        ' Verify this application can be installed.
        Try
            ' the true parameter allows InPlaceHostingManager
            ' to grant the permissions requested in the application manifest. 
            iphm.AssertApplicationRequirements(True)
        Catch ex As Exception
            MessageBox.Show("An error occurred while verifying the application. " & _
                            "Error text: " & ex.Message)
            Return
        End Try

        ' Use the information from GetManifestCompleted() to confirm 
        ' that the user wants to proceed.
        Dim appInfo As String = "Application Name: " & e.ProductName
        appInfo &= ControlChars.Lf & "Version: " & e.Version.ToString()
        appInfo &= ControlChars.Lf & "Support/Help Requests: "

        If Not (e.SupportUri Is Nothing) Then
            appInfo &= e.SupportUri.ToString()
        Else
            appInfo &= "N/A"
        End If

        appInfo &= ControlChars.Lf & ControlChars.Lf & _
            "Confirmed that this application can run with its requested permissions."

        ' If isFullTrust Then
        '    appInfo &= ControlChars.Lf & ControlChars.Lf & _
        '        "This application requires full trust in order to run."
        ' End If

        appInfo &= ControlChars.Lf & ControlChars.Lf & "Proceed with installation?"

        Dim dr As DialogResult = MessageBox.Show(appInfo, _
            "Confirm Application Install", MessageBoxButtons.OKCancel, MessageBoxIcon.Question)
        If dr <> System.Windows.Forms.DialogResult.OK Then
            Return
        End If

        ' Download the deployment manifest. 
        ' Usually, this shouldn't throw an exception unless 
        ' AssertApplicationRequirements() failed, or you did not call that method
        ' before calling this one.
        Try
            iphm.DownloadApplicationAsync()
        Catch downloadEx As Exception
            MessageBox.Show("Cannot initiate download of application. Error: " & downloadEx.Message)
            Return
        End Try
    End Sub

#If 0 Then
    Private Function CheckForFullTrust(ByVal appManifest As XmlReader) As Boolean
        Dim isFullTrust As Boolean = False

        If (appManifest Is Nothing) Then
            Throw New ArgumentNullException("appManifest cannot be null.")
        End If

        Dim xaUnrestricted As 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 Then
            If xaUnrestricted.Value = "true" Then
                Return True
            End If
        End If

        Return False
    End Function
#End If

    Private Sub iphm_DownloadProgressChanged(ByVal sender As Object, ByVal e As DownloadProgressChangedEventArgs) Handles iphm.DownloadProgressChanged
        ' you can show percentage of task completed using e.ProgressPercentage
    End Sub

    Private Sub iphm_DownloadApplicationCompleted(ByVal sender As Object, ByVal e As DownloadApplicationCompletedEventArgs) Handles iphm.DownloadApplicationCompleted
        ' Check for an error.
        If (e.Error IsNot Nothing) Then
            ' Cancel download and install.
            MessageBox.Show("Could not download and install application. Error: " & e.Error.Message)
            Return
        End If

        ' Inform the user that their application is ready for use. 
        MessageBox.Show("Application installed! You may now run it from the Start menu.")
    End Sub

Комментарии

В консольном приложении, так как события назначаются потокам из пула потоков, события хода выполнения обновления могут быть получены не по порядку, при этом последующее событие покажет меньшее значение по сравнению с предыдущим событием.In a console application, since events are assigned to threads out of a thread pool, you might receive update progress events out of order, with a subsequent event showing a decrease compared to a previous event. Такое поведение не будет отображаться в Windows Forms приложении, так как события в Windows Forms обрабатываются последовательно из очереди сообщений потока пользовательского интерфейса.You will not see such behavior in a Windows Forms application, because events in Windows Forms are processed sequentially out of the UI thread's message queue.

Свойства

BytesDownloaded

Возвращает количество байтов данных, загруженных на локальный компьютер.Gets the number of bytes downloaded to the local computer.

ProgressPercentage

Возвращает процент выполнения асинхронной задачи.Gets the asynchronous task progress percentage.

(Унаследовано от ProgressChangedEventArgs)
State

Возвращает состояние хода выполнения загрузки.Gets the progress state of the download.

TotalBytesToDownload

Возвращает общее количество байтов для операции загрузки.Gets the total number of bytes for the download operation.

UserState

Возвращает уникальное пользовательское состояние.Gets a unique user state.

(Унаследовано от ProgressChangedEventArgs)

Методы

Equals(Object)

Определяет, равен ли указанный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Унаследовано от Object)
GetHashCode()

Служит в качестве хэш-функции по умолчанию.Serves as the default hash function.

(Унаследовано от Object)
GetType()

Возвращает объект Type для текущего экземпляра.Gets the Type of the current instance.

(Унаследовано от Object)
MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Унаследовано от Object)
ToString()

Возвращает строку, представляющую текущий объект.Returns a string that represents the current object.

(Унаследовано от Object)

Применяется к