TraceListener that outputs to a textbox

[=?Utf-8?B?YXJjaHVsZXRhMzc=?=]

I want to send trace messages to a textbox in my winforms application using
C# 2.0. I have a custom TraceListener class (see below) that is very basic,
but I'v got an error implementing it that I don't understand. To instantiate
my class I have:

TextboxTraceLis tener TextBoxTracer = new TextboxTraceLis tener(txtLog);

Visual Studio underlines txtLog in blue and says:
"Error 2 A field initializer cannot reference the nonstatic field, method,
or property 'Report2085.frm 2085.txtLog"

Am I trying something that simply won't work without a rewrite or is there a
simple edit I can do to fix this?
using System;
using System.Collecti ons.Generic;
using System.Text;
using System.Diagnost ics;
using System.Windows. Forms;

namespace MyUtil
{
public class TextboxTraceLis tener : TraceListener
{
private TextBox textBox;
public TextboxTraceLis tener(TextBox textBox)
{
this.textBox = textBox;
if (!Trace.Listene rs.Contains(thi s)) {
Trace.Listeners .Add(this); }
}

public override void Write(string message)
{
textBox.Text += message;
}

public override void WriteLine(strin g message)
{
textBox.Text += message + Environment.New Line;
}

}
}

[Patrick Steele]

In article <47************ *************** *******@microso ft.com>,
ar*********@dis cussions.micros oft.com says...

I want to send trace messages to a textbox in my winforms application using
C# 2.0. I have a custom TraceListener class (see below) that is very basic,
but I'v got an error implementing it that I don't understand. To instantiate
my class I have:

TextboxTraceLis tener TextBoxTracer = new TextboxTraceLis tener(txtLog);

Visual Studio underlines txtLog in blue and says:
"Error 2 A field initializer cannot reference the nonstatic field, method,
or property 'Report2085.frm 2085.txtLog"

Where is this code executing? Where in your app is the line of code
shown above?

--
Patrick Steele
http://weblogs.asp.net/psteele

[=?Utf-8?B?YXJjaHVsZXRhMzc=?=]

I believe it's in the member declarations of frm2085.cs. I'll have to answer
this question in more detail on Monday.
Should I be newing up my object within the methods in frm2085.cs that call
them?
"Patrick Steele" wrote:

In article <47************ *************** *******@microso ft.com>,
ar*********@dis cussions.micros oft.com says...

I want to send trace messages to a textbox in my winforms application using
C# 2.0. I have a custom TraceListener class (see below) that is very basic,
but I'v got an error implementing it that I don't understand. To instantiate
my class I have:

TextboxTraceLis tener TextBoxTracer = new TextboxTraceLis tener(txtLog);

Visual Studio underlines txtLog in blue and says:
"Error 2 A field initializer cannot reference the nonstatic field, method,
or property 'Report2085.frm 2085.txtLog"

Where is this code executing? Where in your app is the line of code
shown above?

--
Patrick Steele
http://weblogs.asp.net/psteele

[=?Utf-8?B?YXJjaHVsZXRhMzc=?=]

Hi Patrick,
I've copied and pasted some code below showing how I was trying to do it on
my first try. I also tried putting it in the constructor of the form (see
"current try" below) and this was an imporovement. This way I'm not getting
any errors in the constructor. I'm now getting errors in using it.

I'm using the WriteLine method in my catch statements of various methods in
my frm2085.cs and will be using it in a few other classes. So in my form, I
have a catch statement that looks like this:

catch (Exception e)
{
TextBoxTracer.W riteLine(e.Mess age);
}

and I get this error when it builds:
"Error 3 The name 'TextBoxTracer' does not exist in the current context"

Should the lines I now have in my constructor be cut and pasted into each of
my catch statements or is there something else I should try?
///////////////////////////////////////////////////////
// first try
////////////////////////////////////////////////////
public partial class frm2085 : Form
{
private Excel.Applicati onClass _excel;
private Excel.Workbook _book;
protected Excel.Sheets _sheets;
protected Excel.Worksheet _sheet;
private Int32 headerRow;
TextboxTraceLis tener TextBoxTracer = new TextboxTraceLis tener(txtLog);
Trace.Listeners .Add(TextBoxTra cer);

public frm2085()
{
InitializeCompo nent();
// create a new COM object for excel
_excel = new ApplicationClas s();
}

///////////////////////////////////////////////////////
// current try
////////////////////////////////////////////////////
public frm2085()
{
InitializeCompo nent();
// create a new COM object for excel
_excel = new ApplicationClas s();
TextboxTraceLis tener TextBoxTracer = new
TextboxTraceLis tener(txtLog);
Trace.Listeners .Add(TextBoxTra cer);
}
"Patrick Steele" wrote:

In article <47************ *************** *******@microso ft.com>,
ar*********@dis cussions.micros oft.com says...

I want to send trace messages to a textbox in my winforms application using
C# 2.0. I have a custom TraceListener class (see below) that is very basic,
but I'v got an error implementing it that I don't understand. To instantiate
my class I have:

TextboxTraceLis tener TextBoxTracer = new TextboxTraceLis tener(txtLog);

Visual Studio underlines txtLog in blue and says:
"Error 2 A field initializer cannot reference the nonstatic field, method,
or property 'Report2085.frm 2085.txtLog"

Where is this code executing? Where in your app is the line of code
shown above?

--
Patrick Steele
http://weblogs.asp.net/psteele

[Patrick Steele]

In article <D1************ *************** *******@microso ft.com>,
ar*********@dis cussions.micros oft.com says...

Hi Patrick,
I've copied and pasted some code below showing how I was trying to do it on
my first try. I also tried putting it in the constructor of the form (see
"current try" below) and this was an imporovement. This way I'm not getting
any errors in the constructor. I'm now getting errors in using it.

I'm using the WriteLine method in my catch statements of various methods in
my frm2085.cs and will be using it in a few other classes. So in my form, I
have a catch statement that looks like this:

catch (Exception e)
{
TextBoxTracer.W riteLine(e.Mess age);
}

and I get this error when it builds:
"Error 3 The name 'TextBoxTracer' does not exist in the current context"

Once you add a listener to the Listeners collection, any calls to
Trace.WriteLine should be sent to all listeners. You don't need to
worry about accessing an individual listener (like the one you've
written).

--
Patrick Steele
http://weblogs.asp.net/psteele