I create sample project in VS2012 by
1. menu-File- New Project
2. select "Windows phone direct 3D with XAML App"
3. Edit File CubeRenderer.cpp and one line log in function "void CubeRenderer::Render()"
void CubeRenderer::Render()
OutputDebugStringA("render frame ...\n");

4. Run the project (F5)

But I can not see the "render frame..." shown in VS2012 output windows.

What is wrong? How can I let the log being shown in output window since I need debug the native (C++) code. The breakpoint is not available in C++ code.
BTW, the project is built as "Debug"(not Release)