Understanding the ECOM in Symbian

Symbian also has windows-like
Com mechanism, used as the interface standard between binary modules.
ECOM is much simpler than Windows COM, with no guid
No iunknown, no marshal, no other things...

So, what else is there? One by one

First, like Com, your DLL needs to be registered so that someone else can find you. The difference is that, instead of registering to the registry, the DLL does not lead to injection.
The function of the book anti-registration (not similar
Dllregisterserver and dllunregisterserver), but write an RSS file,
Write your ECOM
Registration Information. the RSC file is generated after the RSS file is compiled and put into the system's ECOM plug-in registration directory.
The system can find your ECOM through the information in this file.
DLL. This RSS is not hard to write, basically just copy a new ID.
Note that the RSC file name generated after RSS compilation must be the same as the DLL file name.

* Note: Here RSS and blog RSS are not a concept. The resource file in Symbian is named RSS.

Then, your dll must implement an extraction function.
Export_c const timplementationproxy *
Implementationgroupproxy (tint & atablecount );
This is required. This function returns a structure array
Describes the ID of all objects contained in the DLL and the pointer of the factory function.
Generally, this function returns global variables in a DLL, for example:
Const
Timplementationproxy implementationtable [] =
{

Implementation_proxy_entry (0x13457890, cfoo: newl)
};

Cfoo: newl returns a cfoo *, and cfoo must implement the interface corresponding to ID 0x13457890.

This is simple. It is very primitive compared with Windows COM, but ECOM is widely used in Symbian and s60.
Because the mobile phone system needs a lot
Most of the features are implemented by ECOM with strong customization capabilities. Most of the differences between different versions depend on distribution.
When using different ECOM. The DLL of ECOM is made into a mobile phone
When Rom is used, it is somewhat different from other common DLL.
In the same way, ECOM will have a separate region, and the indexing will ensure that ECOM loading is faster than other DLL.
Institute
In some cases, some data files are made into ECOM because loading is faster.