ConfigurationElement.IsModified Metod

Definition

Anger om det här konfigurationselementet har ändrats sedan det senast sparades eller lästes in när det implementerades i en härledd klass.

protected public:
 virtual bool IsModified();
protected:
 virtual bool IsModified();
protected internal virtual bool IsModified();
protected virtual bool IsModified();
abstract member IsModified : unit -> bool
override this.IsModified : unit -> bool
Protected Friend Overridable Function IsModified () As Boolean
Protected Overridable Function IsModified () As Boolean

Returer

trueom elementet har ändrats. annars . false

Exempel

I följande exempel visas hur du utökar IsModified.

protected override bool IsModified()
{
    bool ret = base.IsModified();
    // You can enter your custom processing code here.
    return ret;
}
    Protected Overrides Function IsModified() As Boolean
        Dim ret As Boolean = MyBase.IsModified()
        ' Enter your custom processing code here.
        Return ret

    End Function 'IsModified
End Class

Metoden som visas i föregående exempel anropas när ett konfigurationselement ändras, som i följande exempel.

// Show how to use IsModified.
// This method modifies the port property
// of the url element named Microsoft and
// saves the modification to the configuration
// file. This in turn will cause the overriden
// UrlConfigElement.IsModified() mathod to be called. 
static void ModifyElement()
{
    try
    {
        // Get the configuration file.
        System.Configuration.Configuration config =
            ConfigurationManager.OpenExeConfiguration(
            ConfigurationUserLevel.None);

        // Get the MyUrls section.
        UrlsSection myUrlsSection =
            config.GetSection("MyUrls") as UrlsSection;

        UrlsCollection elements = myUrlsSection.Urls;

        IEnumerator elemEnum =
            elements.GetEnumerator();

        int i = 0;
        while (elemEnum.MoveNext())
        {
            if (elements[i].Name == "Microsoft")
            {
                elements[i].Port = 1010;
                bool readOnly = elements[i].IsReadOnly();
                break;
            }
            i += 1;
        }

        if (!myUrlsSection.ElementInformation.IsLocked)
        {

            config.Save(ConfigurationSaveMode.Full);

            // This to obsolete the MyUrls cached 
            // section and read the updated version
            // from the configuration file.
            ConfigurationManager.RefreshSection("MyUrls");
        }
        else
            Console.WriteLine(
                "Section was locked, could not update.");
    }

    catch (ConfigurationErrorsException err)
    {
        Console.WriteLine("[ModifyElement: {0}]",
            err.ToString());
    }
}
' Show how to use IsModified.
' This method modifies the port property
' of the url element named Microsoft and
' saves the modification to the configuration
' file. This in turn will cause the overriden
' UrlConfigElement.IsModified() mathod to be called. 
Shared Sub ModifyElement()
    Try
        ' Get the current configuration file.
        Dim config _
        As System.Configuration.Configuration = _
        ConfigurationManager.OpenExeConfiguration( _
        ConfigurationUserLevel.None)

        ' Get the MyUrls section.
        Dim myUrlsSection As UrlsSection = _
        config.GetSection("MyUrls")


        Dim elements As UrlsCollection = _
        myUrlsSection.Urls


        Dim elemEnum As IEnumerator = _
        elements.GetEnumerator()

        Dim i As Integer = 0
        While elemEnum.MoveNext()
            If elements(i).Name = "Microsoft" Then
                elements(i).Port = 1010
                Dim [readOnly] As Boolean = _
                elements(i).IsReadOnly()
                Exit While
            End If
            i += 1
        End While

        If Not myUrlsSection.ElementInformation.IsLocked Then

            config.Save(ConfigurationSaveMode.Full)

            ' This to obsolete the MyUrls cached 
            ' section and read the updated version 
            ' from the configuration file.
            ConfigurationManager.RefreshSection("MyUrls")
        Else
            Console.WriteLine("Section was locked, could not update.")
        End If

    Catch err As ConfigurationErrorsException
        Console.WriteLine("[ModifyElement: {0}]", _
        err.ToString())
    End Try

End Sub

Kommentarer

Metoden IsModified avgör om det här ConfigurationElement objektet ska skrivas till konfigurationsfilen när Save metoden anropas. Om returvärdet är falseantas det att konfigurationsfilen representerar elementets aktuella tillstånd.

Som standard IsModified returneras true när en egenskap har angetts via indexeraren till det här ConfigurationElement objektet.

Åsidosätt IsModified metoden för att ange anpassad indikation på tillståndet för det här ConfigurationElement elementet.

Gäller för