Trace.WriteLine Method (String, String) (System.Diagnostics)

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.NET Framework Class Library

Trace.WriteLine Method (String, String)

Writes a category name and message to the trace listeners in the Listeners collection.

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

Syntax

Visual Basic

<ConditionalAttribute("TRACE")> _
Public Shared Sub WriteLine ( _
	message As String, _
	category As String _
)

[ConditionalAttribute("TRACE")]
public static void WriteLine(
	string message,
	string category
)

Visual C++

[ConditionalAttribute(L"TRACE")]
public:
static void WriteLine(
	String^ message, 
	String^ category
)

[<ConditionalAttribute("TRACE")>]
static member WriteLine : 
        message:string * 
        category:string -> unit

Parameters

message: Type: System.String
A message to write.

category: Type: System.String
A category name used to organize the output.

Remarks

By default, the output is written to an instance of DefaultTraceListener.

The category parameter can be used to group output messages.

This method calls the WriteLine method of the trace listener.

Examples

The following example creates a TraceSwitch named generalSwitch. This switch is set outside the code sample.

If the switch is set to the TraceLevel Error or higher, the example outputs the first error message to the Listeners. For information on adding a listener to the Listeners collection, see the TraceListenerCollection class.

Then, if the TraceLevel is set to Verbose, the example outputs the second error message and the category on the same line as the first message. The second message is followed by a line terminator.

Visual Basic


    ' Class-level declaration.
    ' Create a TraceSwitch.
    Private Shared generalSwitch As New TraceSwitch("General", "Entire Application")

    Public Shared Sub MyErrorMethod(category As String)
        ' Write the message if the TraceSwitch level is set to Error or higher.
        If generalSwitch.TraceError Then
            Trace.Write("My error message. ")
        End If 
        ' Write a second message if the TraceSwitch level is set to Verbose.
        If generalSwitch.TraceVerbose Then
            Trace.WriteLine("My second error message.", category)
        End If
    End Sub


// Class-level declaration.
 // Create a TraceSwitch.
 static TraceSwitch generalSwitch = new TraceSwitch("General", "Entire Application");

 static public void MyErrorMethod(String category) {
    // Write the message if the TraceSwitch level is set to Error or higher.
    if(generalSwitch.TraceError)
       Trace.Write("My error message. ");

    // Write a second message if the TraceSwitch level is set to Verbose.
    if(generalSwitch.TraceVerbose)
       Trace.WriteLine("My second error message.", category);
 }

Visual C++


// Class-level declaration.
// Create a TraceSwitch.
private:
   static TraceSwitch^ generalSwitch = 
      gcnew TraceSwitch( "General", "Entire Application" );

public:
   static void MyErrorMethod( String^ category )
   {
      #if defined(TRACE)
      // Write the message if the TraceSwitch level 
      // is set to Error or higher.
      if ( generalSwitch->TraceError )
      {
         Trace::Write( "My error message. " );
      }

      // Write a second message if the TraceSwitch level
      // is set to Verbose.
      if ( generalSwitch->TraceVerbose )
      {
         Trace::WriteLine( "My second error message.", category );
      }
      #endif
   }

Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Trace Class

WriteLine Overload

System.Diagnostics Namespace

Debug

Trace

BooleanSwitch

TraceSwitch

TraceListener

DefaultTraceListener

ConditionalAttribute