Write Method (String)

Trace::Write Method (String^)


Writes a message to the trace listeners in the Listeners collection.

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

static void Write(
	String^ message


Type: System::String^

A message to write.

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

This method calls the Write method of the trace listener.


ASP.NET supplies tracing functionality tailored for Web pages. To write trace messages in ASP.NET pages, use the Page::Trace property.

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 TraceLevelError 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. A line terminator follows the second message.

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

   static void MyErrorMethod()
      // 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." );

.NET Framework
Available since 1.1
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