Static interface DLLs

A static interface DLL represents an interface which is defined to its clients by one or more headers for use at compile time, and an import library for use at link time.

When a executable that is a client of the DLL is loaded at run-time, the loader notes that it requires the static interface DLL to be available. The loader then either loads the DLL or, if it is loaded already, attaches the new client to it.

In Symbian platform, all static interface DLLs must have a uid2 of 0x1000008d. The particular static interface DLL is then identified by name and by uid3.

For example, if a DLL called helloview.dll is built with a uid3 of 0x10000252, then the name used in the import library for ARM builds of Symbian platform is helloview[10000252]. When the loader loads the helloview.dll, it checks that its UID is 0x10000252. If the uid3 in the DLL does not match, then the load fails.

mmp project specification

A static interface DLL project file must specify the correct target type and UID:

Specify the TARGETTYPE line as:
```
TARGETTYPE dll
```
This implicitly specifies UID1 correctly.
Specify the UID for the DLL in a UID line:

UID 0x1000008d <UID3>

An example of the mmp project file for a static DLL is given below:

TARGET        CreateStaticDLL.dll
TARGETTYPE    dll
UID           0x1000008d 0x10004268
SOURCEPATH    .
SOURCE        CreateStaticDLL.cpp
USERINCLUDE   .
SYSTEMINCLUDE \Epoc32\include
LIBRARY       euser.lib
EXPORTUNFROZEN

Parent topic: How to build DLLs