TextWriterTraceListener Constructor (String)

 

Initializes a new instance of the TextWriterTraceListener class, using the file as the recipient of the debugging and tracing output.

Namespace:   System.Diagnostics
Assembly:  System (in System.dll)

Public Sub New (
	fileName As String
)

Parameters

fileName
Type: System.String

The name of the file the TextWriterTraceListener writes to.

Exception Condition
ArgumentNullException

The file is null.

This constructor initializes the Name property to an empty string ("").

The following code example creates a TextWriterTraceListener using the TextWriterTraceListener(String) constructor, then adds it to the TraceListenerCollection. The example writes two messages to this TextWriterTraceListener, then writes a message to all TraceListener objects in the TraceListenerCollection. Finally, it flushes and closes the TextWriterTraceListener.

Imports System
Imports System.Diagnostics
Imports Microsoft.VisualBasic

Module TWTLConStringMod

    ' args(0) is the specification of the trace log file.
    Sub Main(ByVal args() As String)

        ' Verify that a parameter was entered.
        If args.Length = 0 Then
            Console.WriteLine("Enter a trace file specification.")

        Else
            ' Create a TextWriterTraceListener object that takes a 
            ' file specification.
            Dim textListener As TextWriterTraceListener
            Try
                textListener = New TextWriterTraceListener(args(0))
                Trace.Listeners.Add(textListener)
            Catch ex As Exception
                Console.WriteLine( _
                    "Error creating TextWriterTraceListener for trace " & _
                    "file ""{0}"":" & vbCrLf & "{1}", args(0), ex.Message)
                Return
            End Try

            ' Write these messages only to the TextWriterTraceListener.
            textListener.WriteLine( _
                "This is trace listener named """ & textListener.Name & """")
            textListener.WriteLine("Trace written to a file: " & _
                vbCrLf & "    """ & args(0) & """")

            ' Write a message to all trace listeners.
            Trace.WriteLine(String.Format( _
                "This trace message written {0} to all listeners.", Now))

            ' Flush and close the output.
            Trace.Flush()
            textListener.Flush()
            textListener.Close()
        End If
    End Sub
End Module

.NET Framework
Available since 1.1
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