Use the constructor to create a new check-box. You may pass a string as the first parameter to display that as a label next to the toggle button. Also, passing true as the second parameter with assign the letter that is preceded by an underscore in the label as the mnemonic for the check-box.
This class is derived and therefore behaves much like a GtkToggleButton. Hence, you may use the signal "toggled" to determine any change in the state of the check-box.