CheckForUpdateCompletedEventArgs.IsUpdateRequired 属性
定义
获取一个指示是否必须安装更新的值。Gets a value indicating whether the update must be installed.
public:
property bool IsUpdateRequired { bool get(); };
public bool IsUpdateRequired { get; }
member this.IsUpdateRequired : bool
Public ReadOnly Property IsUpdateRequired As Boolean
属性值
如果更新是必需的,则为 true;否则为 false。true if the update is required; otherwise, false.
示例
下面的代码示例使用 IsUpdateRequired 来确定是否要求用户安装更新或在不提示的情况下安装更新。The following code example uses IsUpdateRequired to determine whether to ask the user to install the update, or to install it without prompting.
private:
long sizeOfUpdate;
private:
void Form1_Load(Object^ sender, System::EventArgs^ e)
{
DoUpdate();
}
public:
void DoUpdate()
{
if (ApplicationDeployment::IsNetworkDeployed)
{
ApplicationDeployment^ currentAppDeployment =
ApplicationDeployment::CurrentDeployment;
currentAppDeployment->CheckForUpdateCompleted +=
gcnew CheckForUpdateCompletedEventHandler(
this, &Form1::currentDeploy_CheckForUpdateCompleted);
currentAppDeployment->CheckForUpdateAsync();
}
}
// If update is available, fetch it.
void currentDeploy_CheckForUpdateCompleted(Object^ sender,
CheckForUpdateCompletedEventArgs^ e)
{
if (nullptr != e->Error)
{
// Log error.
return;
}
if (e->UpdateAvailable)
{
sizeOfUpdate = (long) e->UpdateSizeBytes;
if (!e->IsUpdateRequired)
{
System::Windows::Forms::DialogResult
updateDialogueResult = MessageBox::Show(
"An update is available.Would you like to update the" +
" application now?", "Update Available",
MessageBoxButtons::OKCancel);
if (System::Windows::Forms::DialogResult::OK ==
updateDialogueResult)
{
BeginUpdate();
}
}
else
{
BeginUpdate();
}
}
}
void BeginUpdate()
{
ApplicationDeployment^ ad = ApplicationDeployment::CurrentDeployment;
ad->UpdateCompleted +=
gcnew AsyncCompletedEventHandler(
this, &Form1::CurrentDeployment_UpdateCompleted);
// Indicate progress in the application's status bar.
ad->UpdateProgressChanged +=
gcnew DeploymentProgressChangedEventHandler(this,
&Form1::ad_ProgressChanged);
ad->UpdateAsync();
}
void CurrentDeployment_UpdateCompleted(Object^ sender,
AsyncCompletedEventArgs^ e)
{
if (!e->Cancelled)
{
if (nullptr != e->Error)
{
System::Windows::Forms::DialogResult
restartDialogueResult = MessageBox::Show(
"The application has been updated. Restart?",
"Restart Application",
MessageBoxButtons::OKCancel);
if (System::Windows::Forms::DialogResult::OK ==
restartDialogueResult)
{
Application::Restart();
}
}
else
{
// Replace with your own error reporting or logging.
MessageBox::Show(
"The application encountered an error in downloading" +
" the latest update. Error: {0}",
e->Error->Message);
}
}
else
{
// Replace with your own error reporting or logging.
MessageBox::Show("The update of the application's latest" +
" version was cancelled.");
}
}
void ad_ProgressChanged(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);
statusStrip1->Text = progressText;
}
long sizeOfUpdate = 0;
private void UpdateApplication()
{
if (ApplicationDeployment.IsNetworkDeployed)
{
ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
ad.CheckForUpdateCompleted += new CheckForUpdateCompletedEventHandler(ad_CheckForUpdateCompleted);
ad.CheckForUpdateProgressChanged += new DeploymentProgressChangedEventHandler(ad_CheckForUpdateProgressChanged);
ad.CheckForUpdateAsync();
}
}
void ad_CheckForUpdateProgressChanged(object sender, DeploymentProgressChangedEventArgs e)
{
downloadStatus.Text = String.Format("Downloading: {0}. {1:D}K of {2:D}K downloaded.", GetProgressString(e.State), e.BytesCompleted/1024, e.BytesTotal/1024);
}
string GetProgressString(DeploymentProgressState state)
{
if (state == DeploymentProgressState.DownloadingApplicationFiles)
{
return "application files";
}
else if (state == DeploymentProgressState.DownloadingApplicationInformation)
{
return "application manifest";
}
else
{
return "deployment manifest";
}
}
void ad_CheckForUpdateCompleted(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;
}
else if (e.Cancelled == true)
{
MessageBox.Show("The update was cancelled.");
}
// Ask the user if they would like to update the application now.
if (e.UpdateAvailable)
{
sizeOfUpdate = e.UpdateSizeBytes;
if (!e.IsUpdateRequired)
{
DialogResult dr = MessageBox.Show("An update is available. Would you like to update the application now?\n\nEstimated Download Time: ", "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();
}
}
}
private void BeginUpdate()
{
ApplicationDeployment ad = ApplicationDeployment.CurrentDeployment;
ad.UpdateCompleted += new AsyncCompletedEventHandler(ad_UpdateCompleted);
// Indicate progress in the application's status bar.
ad.UpdateProgressChanged += new DeploymentProgressChangedEventHandler(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);
downloadStatus.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;
}
else 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();
}
}
Private sizeOfUpdate As Long = 0
Dim WithEvents ADUpdateAsync As ApplicationDeployment
Private Sub UpdateApplication()
If (ApplicationDeployment.IsNetworkDeployed) Then
ADUpdateAsync = ApplicationDeployment.CurrentDeployment
ADUpdateAsync.CheckForUpdateAsync()
End If
End Sub
Private Sub ADUpdateAsync_CheckForUpdateProgressChanged(ByVal sender As Object, ByVal e As DeploymentProgressChangedEventArgs) Handles ADUpdateAsync.CheckForUpdateProgressChanged
DownloadStatus.Text = [String].Format("{0:D}K of {1:D}K downloaded.", e.BytesCompleted / 1024, e.BytesTotal / 1024)
End Sub
Private Sub ADUpdateAsync_CheckForUpdateCompleted(ByVal sender As Object, ByVal e As CheckForUpdateCompletedEventArgs) Handles ADUpdateAsync.CheckForUpdateCompleted
If (e.Error IsNot Nothing) Then
MessageBox.Show(("ERROR: Could not retrieve new version of the application. Reason: " + ControlChars.Lf + e.Error.Message + ControlChars.Lf + "Please report this error to the system administrator."))
Return
Else
If (e.Cancelled = True) Then
MessageBox.Show("The update was cancelled.")
End If
End If
' Ask the user if they would like to update the application now.
If (e.UpdateAvailable) Then
sizeOfUpdate = e.UpdateSizeBytes
If (Not e.IsUpdateRequired) Then
Dim dr As DialogResult = MessageBox.Show("An update is available. Would you like to update the application now?", "Update Available", MessageBoxButtons.OKCancel)
If (System.Windows.Forms.DialogResult.OK = dr) Then
BeginUpdate()
End If
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()
End If
End If
End Sub
Private Sub BeginUpdate()
ADUpdateAsync = ApplicationDeployment.CurrentDeployment
ADUpdateAsync.UpdateAsync()
End Sub
Private Sub ADUpdateAsync_UpdateProgressChanged(ByVal sender As Object, ByVal e As DeploymentProgressChangedEventArgs) Handles ADUpdateAsync.UpdateProgressChanged
Dim progressText As String = String.Format("{0:D}K out of {1:D}K downloaded - {2:D}% complete", e.BytesCompleted / 1024, e.BytesTotal / 1024, e.ProgressPercentage)
DownloadStatus.Text = progressText
End Sub
Private Sub ADUpdateAsync_UpdateCompleted(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs) Handles ADUpdateAsync.UpdateCompleted
If (e.Cancelled) Then
MessageBox.Show("The update of the application's latest version was cancelled.")
Exit Sub
Else
If (e.Error IsNot Nothing) Then
MessageBox.Show("ERROR: Could not install the latest version of the application. Reason: " + ControlChars.Lf + e.Error.Message + ControlChars.Lf + "Please report this error to the system administrator.")
Exit Sub
End If
End If
Dim dr As DialogResult = 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 (dr = System.Windows.Forms.DialogResult.OK) Then
Application.Restart()
End If
End Sub
注解
当你将更新部署到 ClickOnce 应用程序时,可以将其标记为必需更新,并向应用程序发出信号,通知应立即升级该应用程序。When you deploy an update to your ClickOnce application, you can mark it as a required update, signaling to your application that it should upgrade immediately. 如果最新版本包含关键更新,或者它与早期版本使用的文件格式或后端数据源不兼容,则需要标记更新。You want mark the update if the latest version contains a critical update, or if it is incompatible with file formats or back-end data sources used by the former version.