Getting Problem TargetVersion from 1.6 to 1.5 in Android?

I have developed an application with Target build as API 开发者_Python百科4. It supports Normal Screen and all Densities. But Now i would need to set the App's Target as API 3. In Eclipse Environment, I changed the Build Target to API 3. But I get the Following Error.

• R file gone Automatically. So i get Can not Resolved error allover my app where R is present.
• drawable-ldpi,drawable-mdpi,drawable-hdpi, value-long,etc are not supported.

How to Downgrade my app to Android 1.5 and It should can accessible on up to Android 2.1? Any Idea?

Don't forget about -v4 and other things http://developer.android.com/guide/practices/screens_support.html#strategies

<uses-sdk 
      android:minSdkVersion="3" android:targetSdkVersion="8"/>

And a "Project->Clean…" should be your friend.

1. ldpi, mdpi, hdpi are only supported in Android 1.6+, so you have to move images to a single drawable folder.
2. set minSdkVersion to 3, and targetSdkVersion to 7
3. Project -> Clean to generate new R resources