ConfigurationElement.IsModified 方法

定義

在衍生類別中進行實作時,指出這個組態項目自上次儲存或載入後是否已修改。Indicates whether this configuration element has been modified since it was last saved or loaded, when implemented in a derived class.

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

傳回

如果項目已修改則為 true,否則為 falsetrue if the element has been modified; otherwise, false.

範例

下列範例顯示如何擴充 IsModifiedThe following example shows how to extend 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

在修改設定元素時,會呼叫上一個範例中所顯示的方法,如下列範例所示。The method shown in the previous example is called when a configuration element is modified, as in the following example.

// 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

備註

@No__t-0 方法會決定呼叫 @no__t 2 方法時,是否要將此 @no__t 1 物件寫入至設定檔。The IsModified method determines whether this ConfigurationElement object will be written to the configuration file when the Save method is called. 如果傳回值為 false,則假設此組態檔表示目前的項目之狀態。If the return value is false, it is assumed that the configuration file represents the current state of the element.

根據預設,在透過此 @no__t 2 物件的索引子設定屬性之後,IsModified 會傳回 trueBy default, IsModified returns true after a property is set through the indexer to this ConfigurationElement object.

覆寫 IsModified 方法,以提供這個 @no__t 1 元素狀態的自訂指示。Override the IsModified method to provide custom indication of the state of this ConfigurationElement element.

適用於