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Trace.WriteLine Method (Object, String)

Writes a category name and the value of the object's ToString method to the trace listeners in the Listeners collection.

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

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


Type: System.Object

An Object whose name is sent to the Listeners.

Type: System.String

A category name used to organize the output.

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.

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 on the same line as the first message. The second message is followed by a line terminator.

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

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

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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