The Qt project is very similar to C++ one. Except using of Qt Meta Object Compiler.

Here is a short quotation from 'Qt reference documentation' :

The moc reads a class declaration and produces a C++ source file containing the names of all signals and slots for that class (and a little more). This C++ source file the moc outputs must be compiled and linked with the implementation of the class (or it can be #included into the source file).

Let's take 'hello' example from Qt distribution. There is header file 'hello.h' and source file 'hello.cpp'. The 'hello.h' file must be passed through moc preprocessor and get 'moc_hello.cpp' as a result:

$ moc hello.h -o moc_hello.cpp

$ g++ -o hello main.cpp hello.cpp moc_hello.cpp \
        -I/usr/lib/qt/include -L/usr/lib/qt/lib \
        -L/usr/X11/lib -lX11 -lXext -lqt

To create 'hello' example from Qt distribution in C-Forge you have to take following steps:

1. Create new project with the target name 'hello'

2. Enter target name 'hello' and do not to forget to change target type to 'C++ executable'. Check out 'Use Directory Layout' button.

3. Initialize Qt includes directory search path.

Add '/usr/X11/include' and '/usr/lib/qt/include' to Tools Options / GNU C Compiler / Preprocessor Options / Include Directory Search.

4. Initialize library directory search and used libraries list.

Add '/usr/lib/qt/lib' and '/usr/X11/lib' to Tools Options / Link Editor / Linker Options / Library Directory Search.
Add 'X11', 'qt' to Tools Options / Link Editor / Linker Options / Used Libraries.

Further, you have two ways (each of them has both positive and negative sides):

First:

• Add source *.cpp files (main.cpp, hello.cpp) to target (using button). Simply select all of them in /usr/lib/qt/examples/hello/ directory. For multiselect use Ctrl.
  Note: do not disable 'Project specific' button, for copying these files to your project directory.
  

   

• Create new target with name moc_hello.o and type 'Qt MOC object file'
  

   

• Add 'hello.h' as a source (using button) to target 'moc_hello.o' (same as .cpp files from Qt examples directory)
• Link this object file (moc_hello.o) to executable 'hello', to do it - move the cursor to object file, and Ctrl-Shift Drag'n'Drop (using mouse button 2) it to executable:
  

   

• Add all .cpp files (main.cpp, hello.cpp) to target from Qt Examples directory as shown here
• Using Drag'n'Drop (Mouse button 2) move sources to Working Project Desktop:
  

   

• Add a new source (using button) with the name "moc_hello.qt".

  Note: the name of newly created file - 'moc_hello.qt', not 'hello.qt'.

  

   

• Move 'moc_hello.qt' to Working Project Desktop too.

  Now your project looks like this:

  

   

• Using editor, replace string '#include "hello.h"' with string '#include "moc_hello.qt"' in all .cpp files (main.cpp, hello.cpp).
• Open in editor 'moc_hello.qt' and insert there contents of file 'hello.h' from Qt Examples directory, using File / Insert dialog:
  

   

• Now, to make a target, move the selection in the dependency tree to it, and press button.
• If the target compiled without errors, double click on it to execute and get: