Building Applications
Pocket Dyalog provides the means to create software applications for the Pocket PC which can be distributed electronically and installed using standard techniques.
Pocket Dyalog also supports the facility to create evaluation versions of software packages that automatically expire after a given number of days from the date of installation. This provides you with a mechanism for supplying a free trial version of your software which the user may simply and conveniently replace with a full chargeable version after evaluation.
Full and Evaluation Programs
An evaluation program is intended for allowing end-users to try out an application - free of charge - before they purchase the full version. Pocket Dyalog automatically provides an expiry feature and will refuse to execute an evaluation program after a given number of days since it was installed.
Note that Pocket Dyalog cannot provide complete protection against permanent use of your evaluation software. An end-user could circumvent the protection mechanism by performing a hard reset and re-installing your evaluation package every time it expires. If you wish to add additional incentives to upgrade, you may choose to provide lower functionality in the evaluation version of your application.
To support this system, there are two versions of the Pocket Dyalog Engine; an evaluation version that can be downloaded free of charge, and a full version that is included with the full version of Pocket Dyalog or may be purchased separately. Both versions of the Pocket Dyalog Engine can be obtained from Handango.
An evaluation.exe, created using Pocket Dyalog, will run if the end-user has either the evaluation (free) or full version of the Pocket Dyalog Engine. A full .exe will only run if the user has the full version of the Pocket Dyalog Engine.
The anatomy of an Application
A distributable Pocket PC application (let's call it myapp) is packaged as a single .zip file (e.g. myapp.zip) that (typically) the end-user may download from an internet site such as Handango onto a desktop computer.
On the desktop computer, the user unpacks the .zip file with pkunzip or Winzip to produce 3 files as shown below.
File Name |
Description |
setup.exe
|
A program that installs myapp onto a PDA |
| app.arm.cab |
A compressed file that contains all of the programs and data files that make up the myapp application. |
| app.ini |
The parameter file for setup.exe |
The user connects the PDA to the desktop computer, using Microsoft ActiveSync, and runs setup.exe. This program unpacks the files (including the main program file myapp.exe) from app.arm.CAB and installs them in the appropriate directories on the Pocket PC.
Want to know more?
Id you'd like to learn more about building and evaluating Pocket Dyalog applications please click on the links below.
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