UID

A UID is a globally unique identifier consisting of a 32-bit number used to uniquely identify, for example, an object or file type. In S60 development, objects are identified by compound identifiers that are constructed from three UIDs. These UIDs are called UID1, UID2, and UID3.

In S60 application projects, UID1 is automatically specified by the build tools based on the TARGETTYPE keyword of the project's mmp file. The table below lists the UIDs for some commonly used project types. As the table below shows, the requirements for UID2 and UID3 vary based on the type of the project.

You need to:

• specify the appropriate UID2 (according to the project type) and UID3 values for the UID keyword in the project mmp file.

• use the UID3 in your application code (in the CAknApplication class). For more information on the class requirements for GUI-based applications, see Figure 33

• add the UID3 to the pkg file .

There are two unprotected UID ranges that can be used for UID3 values as follows:

• For self-signed applications, it is recommended that you use UIDs from the following range of unprotected UIDs:

  0xA0000000 to 0xAFFFFFFF

  For more information, see UID of self-signed applications in the Forum Nokia technical library.

• For testing purposes, you can use an UID from the following range without applying for it from Symbian:

  0xE0000000 to 0xEFFFFFFF

Symbian manages the allocation of UIDs. Developers can request UIDs either individually or in preallocated blocks by going to the Symbian Signed website.

For more information, see How to use UIDs and Building, debugging and deploying an application in the Symbian OS Library..