Android dalvik problem

Please i have different platforms installed. I just wanted to know what am supposed to do. If i develop with 3.0 platform, would those with a 2.2 be able to use my app??..

The second question which is the main question is I always get this error when i create android projects.. [2011-05-16 16:32:21 - Hello World] Dx no classfiles specified [2011-05-16 16:32:21 - Hello World] Conversion to Dalvi开发者_运维知识库k format failed with error 1

What do I do to it?

There are several reports out there for that error (e.g., this one. All the solutions point simply to reload the project (select it in the tree at your left, and press F5).

Regarding the first question, unless you want to support Honeycomb-only features, then set up the api level to 8 (Froyo).

Eclair, Froyo and Gingerbread are android versions 2.1, 2.2 and 2.3 respectively (also referred in the documentation as API levels 7, 8 and 9). See the table here. If you want to support just mobile phones, set your target to 2.1 or even lower. That way you will be able to target most of the phones in the market. Your app will also run in Honeycomb (3.x) devices.

Honeycomb has new features to support larger screen devices, so if that is your main target, you might consider taking advantage of those features and drop cell phone support. All will depend on what is your objective.

you should have a look at the minSdk and targetSdk features of a manifest file :

<uses-sdk android:minSdkVersion="4" android:targetSdkVersion="8" />

This will help you target a android sdk version and precise what is the minimum sdk level that can run your app.

Regards, Steff

Developing for Honeycomb or non-tablet version of Android, is different in various things. Your 2.2 application should run correctly on a tablet, but if you want to optimize the graphical interface and use all the notification and other things included only in Honeycomb, then you must use the appropriate API. Until Ice Cream Sandwich is released, we have to develope two different application for the best result.

Regarding the error you get with android projects (I suppose under eclipse?) you'll find some detail at this link, but if you follow all the instruction provided by google in the developers page, you'll be able to write and run your Hello World application.