debug-class-cpp-cli.md

description	title	ms.date	helpviewer_keywords	ms.assetid
Learn more about: Debug Class (C++/CLI)	Debug Class (C++/CLI)	11/04/2016	Trace class, Visual C++ .NET Framework [C++], Debug class Debug class	076bd528-1b6f-4e8a-a372-eb5849cf969a

Debug Class (C++/CLI)

When using xref:System.Diagnostics.Debug in a Visual C++ application, the behavior does not change between a debug and a release build.

Remarks

The behavior for xref:System.Diagnostics.Trace is identical to the behavior for the Debug class, but is dependent on the symbol TRACE being defined. This means that you must #ifdef any Trace-related code to prevent debug behavior in a release build.

Example: Always executes output statements

Description

The following sample always executes the output statements, regardless of whether you compile with /DDEBUG or /DTRACE.

Code

// mcpp_debug_class.cpp
// compile with: /clr
#using <system.dll>
using namespace System::Diagnostics;
using namespace System;

int main() {
   Trace::Listeners->Add( gcnew TextWriterTraceListener( Console::Out ) );
   Trace::AutoFlush = true;
   Trace::Indent();
   Trace::WriteLine( "Entering Main" );
   Console::WriteLine( "Hello World." );
   Trace::WriteLine( "Exiting Main" );
   Trace::Unindent();

   Debug::WriteLine("test");
}

Output

    Entering Main
Hello World.
    Exiting Main
test

Example: Use #ifdef and #endif directives

Description

To get the expected behavior (that is, no "test" output printed for a release build), you must use the #ifdef and #endif directives. The previous code sample is modified below to demonstrate this fix:

Code

// mcpp_debug_class2.cpp
// compile with: /clr
#using <system.dll>
using namespace System::Diagnostics;
using namespace System;

int main() {
   Trace::Listeners->Add( gcnew TextWriterTraceListener( Console::Out ) );
   Trace::AutoFlush = true;
   Trace::Indent();

#ifdef TRACE   // checks for a debug build
   Trace::WriteLine( "Entering Main" );
   Console::WriteLine( "Hello World." );
   Trace::WriteLine( "Exiting Main" );
#endif
   Trace::Unindent();

#ifdef DEBUG   // checks for a debug build
   Debug::WriteLine("test");
#endif   //ends the conditional block
}

See also

.NET Programming with C++/CLI (Visual C++)