. Net – is there a textwriter subclass that triggers an event when writing text?

I wrote a method that accepts textwriter as a parameter (usually console. Out, but not necessarily)

When I call this method, I write some progress information to textwriter However, since this method may run for a long time, I want to update my UI with some status information

At present, I use stringwriter, but it has no events So the first time I get results from stringwriter is after the method is completed

Now I'm searching for a class that inherits from textwriter and triggers textchanged event or similar I know this shouldn't be hard to achieve, but I bet the CLR team has done it for me and I can't find a suitable course

Solution

If anyone is interested, this is a class that extends the stringwriter () class, every time the writer is called Event triggered after flush()

I also added posibility to automatically call flush () after each write, because in my case, the third-party component, written to the console, does not perform refresh

Sample usage:

void DoIt()
{
    var writer = new StringWriterExt(true); // true = AutoFlush
    writer.Flushed += new StringWriterExt.FlushedEventHandler(writer_Flushed);

    TextWriter stdout = Console.Out;
    try
    {
        Console.SetOut(writer);
        CallLongRunningMethodThatDumpsInfoOnConsole();
    }
    finally
    {
        Console.SetOut(stdout);
    }
}

Now I can display some status information in time without waiting for the method to complete

void writer_Flushed(object sender,EventArgs args)
{
    UpdateUi(sender.ToString());
}

This is the class:

public class StringWriterExt : StringWriter
{
    [EditorBrowsable(EditorBrowsableState.Never)]
    public delegate void FlushedEventHandler(object sender,EventArgs args);
    public event FlushedEventHandler Flushed;
    public virtual bool AutoFlush { get; set; }

    public StringWriterExt()
        : base() { }

    public StringWriterExt(bool autoFlush)
        : base() { this.AutoFlush = autoFlush; }

    protected void OnFlush()
    {
        var eh = Flushed;
        if (eh != null)
            eh(this,EventArgs.Empty);
    }

    public override void Flush()
    {
        base.Flush();
        OnFlush();
    }

    public override void Write(char value)
    {
        base.Write(value);
        if (AutoFlush) Flush();
    }

    public override void Write(string value)
    {
        base.Write(value);
        if (AutoFlush) Flush();
    }

    public override void Write(char[] buffer,int index,int count)
    {
        base.Write(buffer,index,count);
        if (AutoFlush) Flush();
    }
}