调度程序的 Log4net 自定义附加程序问题？

Question

我有一个自定义 log4netappender、一个后台工作程序和一个 wpf 富文本框的问题。当我从后台线程登录时，富文本框未正确更新。

当我从主线程调用记录器时，文本会正确记录到 UI 组件（richtextbox）。但是当我从 BackgroundWorker 调用记录器时，会引发记录器 Append 事件，但 UI（richtextbox）永远不会更新......为什么会这样？

感谢您的帮助！

这是我的主窗口代码，其中包含一个用于启动 backgroundworker 的按钮和一个名为“RichTraceBox”的自定义控件：

     private static readonly log4net.ILog _logger = log4net.LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

     TraceBox TheTraceBox;

     public MainPanel()
    {
        InitializeComponent();

        // Configure Log4Net
        Hierarchy hierarchy = (Hierarchy)LogManager.GetRepository();
        hierarchy.Root.RemoveAllAppenders(); /*Remove any other appenders*/           
        //// .... create and configure appender ...///
        WpfRichTextBoxAppender notify = new WpfRichTextBoxAppender(this.TheTraceBox);
        PatternLayout layout = new PatternLayout();
        layout.ConversionPattern = "%d [%t] %-5p %c %m%n";
        notify.Layout = layout;
        notify.ActivateOptions();


        log4net.Config.BasicConfigurator.Configure(notify);
        _logger.Debug("Correctly logged");

        }

 private void button1_Click(object sender, RoutedEventArgs e)
    {
        BackgroundWorker checkGraphlongWorker = new BackgroundWorker();
        checkGraphlongWorker.DoWork += new DoWorkEventHandler(checkGraphlongWorker_DoWork);
        checkGraphlongWorker.RunWorkerAsync();

    }

    void checkGraphlongWorker_DoWork(object sender, DoWorkEventArgs e)
    {
        Thread.Sleep(2000);
        _logger.Debug("This is never Logged....");

        this.TheTraceBox.DisplayOnTraceBox("...But this is corectly displayed ???!!", Brushes.Red);


        }
...}

这是我的“WpfRichTextBoxAppender”，一个用于 log4net 的自定义附加程序，它在包含 wpf richTextBox 的自定义控件上显示消息：

   /// <summary>
/// Description of RichTextBoxAppender.
/// </summary>
public class WpfRichTextBoxAppender : AppenderSkeleton
{
    #region Private Instance Fields
    private TraceBox richTextBox = null;
    private int maxTextLength = 100000;
    #endregion

    private delegate void UpdateControlDelegate(LoggingEvent loggingEvent);

    #region Constructor
    public WpfRichTextBoxAppender(TraceBox myRichTextBox)
        : base()
    {
        richTextBox = myRichTextBox;
    }
    #endregion


    protected override void Append(LoggingEvent[] loggingEvents)
    {
        base.Append(loggingEvents);
    }

    protected override void Append(LoggingEvent loggingEvent)
    {

        if (richTextBox != null)
        {
            // There may be performance issues if the buffer gets too long
            // So periodically clear the buffer
            if (richTextBox.TextLenght > maxTextLength)
            {
                richTextBox.ClearTrace();
            }
            Brush color = Brushes.Black;
            if (loggingEvent.Level == Level.Alert)
                color = Brushes.Orange;
            else if (loggingEvent.Level == Level.Critical)
                color = Brushes.DarkOrange;
            else if (loggingEvent.Level == Level.Error)
                color = Brushes.Red;
            else if (loggingEvent.Level == Level.Fatal)
                color = Brushes.Red;
            else if (loggingEvent.Level == Level.Warn)
                color = Brushes.OrangeRed;
            this.richTextBox.DisplayOnTraceBox(RenderLoggingEvent(loggingEvent), color);
        }
    }
}


 public partial class TraceBox : UserControl
{
    public TraceBox()
    {
        InitializeComponent();
        this.Visibility = System.Windows.Visibility.Visible;
    }        

    private void Button_Clear_Click(object sender, RoutedEventArgs e)
    {
        this.ClearTrace();
        //this.Output.Text = "";
    }


    public void ClearTrace()
    {
        FlowDocument myFlowDoc = new FlowDocument();
        this.ConsoleOutputTextBox.Document = myFlowDoc;
    }


    public int TextLenght {
       get
       {
           TextRange tr = new TextRange(this.ConsoleOutputTextBox.Document.ContentStart, this.ConsoleOutputTextBox.Document.ContentEnd);
           return tr.Text.Length;
        }
    }

    private delegate void DisplayOnTraceBoxDel(object message, Brush messageColor);
    public void DisplayOnTraceBox(object message, Brush messageColor)
    {            
        if (!this.ConsoleOutputTextBox.Dispatcher.CheckAccess())
        {
            this.ConsoleOutputTextBox.Dispatcher.Invoke(new DisplayOnTraceBoxDel(DisplayOnTraceBox), DispatcherPriority.DataBind, new object[] { message, messageColor });
        }
        else
        {
            TextRange tr = new TextRange(this.ConsoleOutputTextBox.Document.ContentEnd, this.ConsoleOutputTextBox.Document.ContentEnd);
            tr.Text = message.ToString();
            tr.ApplyPropertyValue(TextElement.FontFamilyProperty, "Consolas");
            tr.ApplyPropertyValue(TextElement.FontSizeProperty, 10D);
            tr.ApplyPropertyValue(Paragraph.MarginProperty, new Thickness(0));
            //tr.ApplyPropertyValue(Paragraph.BackgroundProperty, "LightSteelBlue");
            tr.ApplyPropertyValue(TextElement.ForegroundProperty, messageColor);
            this.ConsoleOutputTextBox.UpdateLayout();
        }
    }


}

Answer 1

我没有使用过 WPF，所以我无法真正评论为什么，具体来说，它没有像您期望的那样工作。但是，我确实找到了这个link to a blog posting，其中peteohanlon 展示了如何制作一个将其输出重定向到WPF 文本框的log4net Appender。他特别提到使用 INotifyPropertyChanged。也许他的帖子中的某些内容会对您有所帮助。

另外，这是我在 SO 上发布的另一个答案的链接，该链接指向几个基于 TextBox 的 Appender（不幸的是，我认为它们都不是 WPF）：

BackgroundWorker & Timer, reading only new lines of a log file?

Answer 2

我遇到了同样的问题，并用段落项目解决了它，所以......

            _textBox.Dispatcher.BeginInvoke(new Action<string>(s =>
            {      
                Paragraph p = new Paragraph();
                p.Inlines.Add(new Run(s) { Foreground = Brushes.Red });
                ((RichTextBox)_textBox).Document.Blocks.Add(p);
            }), msg);