Typically when you create an application, there are cases where you need to create an enumerated set of command IDs (which are symbols with integer values). These defined symbols can then be used in both your code and resource files. Common examples of these cases, include:
Custom command IDs used for mapping mobile device user input
based upon Options menu selections to command handling.
These custom command IDs are mapped to the text displayed for the command
in the Options menu in resource files, and then are passed
back to the application by the application framework.
Control IDs in dialogs to allow references to the dialog controls from C++ code.
For more information on control IDs for dialogs, see Using Dialogs API.
Application view IDs. Note that these could also be enumerated in the header files for the views.
IDs for other resource structures, such as for TABS in
the status pane.
These enumerated values need to be defined in a resource file, which
by convention has the extension hrh, The syntax is as
follows:
enum TCommandIds
{
ECmdAppTest1 = 1,
ECmdView1Cmd1,
ECmdView1Cmd2,
ECmdView1Cmd3,
ECmdView2Cmd1,
ECmdView2Cmd2,
ECmdView2Cmd3,
ECmdView2Cmd4
};
where
enum is the keyword declaration the
set of integer values. Note that you would use this keyword for each set of
enumerated values you defined.
TCommandIds is a label for the list
of enumerated values. This label is not used in the code or resource files.
ECmdAppTest1 is a symbol that can be
used in your code or resource files
= is the operator used for setting the
value to the symbol
1 is the specific value assigned to
the enumerator symbol
Each enumerator is followed by a ,, except for
the last value. It is recommended to have a final ; after
the enumerated list. If a specific value is not assigned to a symbol in the
enumerated list, then the value is that of the previous enumerator plus one.
Thus, the value for ECmdView1Cmd1 above is 2.
For more information about the use of the enum statement,
see ENUM statement in the Symbian OS Library.