Debug Class (C++/CLI)
When using Debug in a Visual C++ application, the behavior does not change between a debug and a release build.
Remarks
The behavior for 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
}