by Ted Daniel -- Source: www.newlc.com
Go-DB supports loading external DLLs via simple GBasic APIs. Although most of the widgets neccessary for business application development are avaiable in Go-DB, you may in certain cases want to extend a particular platform for reasons best suited for your requirement be it for your application related needs or simply having fun. Find out how to use Go-DB to obtain IMEI number(International Mobile Equipment Identity) from your Go-DB application. In a later article, i will explain how to send SMS from your Go-DB application from a Sony Ericsson p910i phone.
Any cross platform application development at a particular point may need to extend a particular platform. Like any good cross platform development tool, Go-DB offers features which enable developers to fully extend a platform’s full capability. This article focuses on certain APIs in GBasic and how to use them to hook your DLL built using Symbian SDK.
Step 1
You will need GStudio 3.4 (now a newer version 3.6 is available for download) final realease. Get a trial copy from http://www.go-db.com. You will also need Symbian module , which can be downloaded from the same location. (comes pre-installed with version 3.6. So no need to do this step)
Step 2
Download and install a Symbian SDK. For this particular example any SDK for Symbian OS version 6.0 and above is needed. I have used UIQ 2.1 SDK wincw version, downloadable from Sony Ericsson developer site(http://developer.sonyericsson.com)
NOTE: You dont need to have Codewarrior to get this example working.
Step 3
Download the sources for this tutorial, downloadable with this article. Download and unzip to your Symbian install drive.Open a command prompt window and issue these commands.
bldmake bldfiles
abld build armi urel
This will buid the DLL. Pre-built SIS files are located in Group directory. SIS file installation will copy IMEIDLL.DLL to /system/libs directory on your device. Change the pkg file located in Group directory to suit your requirement.
Step 4
Build the Go-DB project in release mode. Create a SIS file for your device and install it. Click on "Fetch IMEI" button and a message box will pop-up displaying your device’s IMEI number.
The Source code is as Follows
Listing 1. Symbian cpp source code
Our DLL exports one function whose definition is EXPORT_C long GetIMEICode(char *str); and the implementation is as follows
{
int i= 0;
TBuf<256> Path;
TPlpVariantMachineId imei;
PlpVariant::GetMachineIdL(imei);
Path.Copy(imei);
for(i=0;i < Path.Length();i++)
{
str[i] = Path[i];
}
str[i] = '\0';
return 1;
}
Note that Go-DB understands "char *" only as parameters to functions.Converting to and from Symbian Descriptors is neccessary.After freezing the dll and building the project, note that a .DEF file will be created which will list the functions exported and theordinal associated with it.Our .DEF bundled with source shows the following.
EXPORTS
E32Dll__F10TDllReason @ 1 NONAME R3UNUSED ; E32Dll(TDllReason)
GetIMEICode__FPc @ 2 NONAME R3UNUSED ; GetIMEICode(char *)
We are not interested in E32Dll , just GetIMEICode. The ordinal as given to us is 2. This ordinal will be needed by our GBasic Code.
Note: To freeze a dll after exports have been identified and defined properly, issue this command
abld freeze armi
Listing 2. Go-DB source code
st1$="Initial String"
h = loadlib("\\system\\libs\\IMEIDLL.dll")
if h <> -1 then
ret = calllibfunc(h,"2",st1$)
msgbox("IMEI Code is " + st1$)
unloadlib(h)
else
msgbox("Failed loading IMEIDLL.DLL")
end if
End Sub
We load the IMEIDLL first using loadlib function, if the function gets loaded properly, then the handle it returns will not be -1. Once we obtain the handle , use the handle in calllibfunc to execute the exported function. As explained in Listing 1, use "2" as Function Name. After the function call, st1$ will hold the IMEI number.
GoDB-IMEI.zip
7.6 kb
Here Is some additional Sony Ericsson Cell phone resources with reviews and features for
Sony Ericsson Cell Phones if you or your readers are interested
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