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Trace.Write Method (String, String)

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

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

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

Parameters

message
Type: System.String

A message to write.

category
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 Write method of the trace listener.

NoteNote:

ASP.NET supplies tracing functionality tailored for Web pages. To write trace messages in ASP.NET pages, use the Page.Trace property. For more information about tracing in ASP.NET pages, see the ASP.NET Tracing Overview.

By default, in code associated with an ASP.NET Web page, the statement Trace.Write("...") is a call to the Write method of the Page.Trace property. To use the System.Diagnostics.Trace class in Web pages, you must include the namespace, for example, System.Diagnostics.Trace.Write("...").

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

If the switch is set to the TraceLevel Verbose, 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 Error or higher, 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. 
 static TraceSwitch generalSwitch = new TraceSwitch("General", "Entire Application");

 static public void MyErrorMethod(Object myObject, String category) {
    // Write the message if the TraceSwitch level is set to Verbose. 
    if(generalSwitch.TraceVerbose)
       Trace.Write(myObject.ToString() + " is not a valid object for category: ", 
          category);

    // Write a second message if the TraceSwitch level is set to Error or higher. 
    if(generalSwitch.TraceError)
       Trace.WriteLine(" Please use a different category.");
 }

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

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

.NET Compact Framework

Supported in: 3.5

XNA Framework

Supported in: 3.0, 2.0, 1.0

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