问题
I am a newbie in Blackberry Development and has got stuck on a very complex thing. I have to make an application which should be support all O.S 6 and 0.S 7 based mobile phones.
Now I have different screen resolutions for different handsets in BB OS 6 and 7.
Now how can i manage my background images, and its button positions to be synced on all size of devices.
I have created an images for the screen size of 640x480 and according to it I have placed some button on x,y positions. now if i install the same app on a screen size of 480x360 how can i manage the x,y positions and manage the background size according to device width and height.
Can anybody help? I am complete newbie.
回答1:
Use preprocessor, built-in to Eclipse JDE-plugin, or third-party preprocessor and BlackBerry Ant Tools
Compile separate applications for different RIM OS versions using the same source code files with preprocessor directives inside.
Technically an application compiled with RIM SDK 6.0 is compatible with device with RIM OS 7.0, but to provide the best user experience make separate applications for separate RIM OS versions.
On preprocessing include those image files which are suitable for building a particular application version. If you need to support many screen sizes, then add the biggest possible images to your project and then scale them down at the runtime. Scaling down almost does not affect image quality.
Upon ant build process employ Alx task to collect all information about separate application versions into one alx file.
As a result you will have one alx file (application descriptor file, it is an xml-file), and a set of folders with cod files inside.
When all cod files are signed, you can also do it upon ant build process distribute this alx file with all folders with cod files as one zip archive.
Customer unzips this archive, connects device via usb to the computer, launches BlackBerry Desktop Manager and selects this one alx file. Directives generated by alx task will guide BlackBerry Desktop Manager to install application suitable for the device RIM OS version.
If you want to distribute your application wirelessly, then employ jadtool task and make a php page that reads browser user agent and redirects browser to a relevant jad file.
Before using OTA (over the air) method for distributing your application, add the following MIME-type instructions to the .htaccess file of your web-server.
AddType text/vnd.sun.j2me.app-descriptor jad
AddType application/java-archive jar
AddType application/vnd.rim.cod cod
回答2:
While the approach suggested does provide the best user experience, it is also the most complex to manage.
Personally I try very hard to make one executable and have it evaluate at run time what it needs to do based on the form factor of the device. This is actually easier than you might think, helped significantly by the fact that most screens about the same width. So you can do things like scale your assets to match a proportion of the screen width, based on the screen resolution, and they will look OK on most devices.
And while there are some nice things to be had by using stuff that is specific to say OS7, at this stage I think you should focus on the bread and butter stuff that you can do with OS 5. So, I would recommend you develop something for OS 5.0 - it will run on OS 6.0 and OS 7.0 devices. Create the UI generically to cope with various screen sizes. Later, if you need to get more sophisticated, you can use the tools that have been described.
You will find more on how I try to do things by looking at this. http://supportforums.blackberry.com/t5/Java-Development/Tutorials-for-new-developers-Part-1/m-p/1621711#M194036 I would suggest you look at tutorial 10.
I also recommend a cruise around here: http://developer.blackberry.com/java/
One final thing though, are you aware that Java phones are no longer being developed by BlackBerry? If you are just starting development, you might consider learning C++/Cascades and developing for the BB10 phones.
来源：https://stackoverflow.com/questions/17944306/same-application-on-different-blackberry-handsets