Android modifies the method in the high Jar package version of the project _android

Android App installation package APK if it was developed on a newer Android jar and couldn't run on a lower version of the Android SDK, we needed to recompile a apk with a lower version of the Android jar package that we had developed. So how to simply modify it in a later version of the project:

1, eclipse in the click of the project->properties-> Android in the right side of the interface to select the Android 2.2 can be (if your Android SDK contains the two versions of the Android Jar package)
or open the Default.properties file, at the root of the project, modify TARGET=ANDROID-10 (2.3) to target=android-8 (2.2) so that the original Android jar 2.3 was modified to Android Jar 2.2. Save after the modification, Eclipse automatically replaces the Android jar 2.3 in the project with the Android Jar 2.2
2, open Androidmanifest.xml file, will <uses-sdk android:minsdkversion= "ten"/> Modified to <USES-SDK android:minsdkversion= "8" /> Save the file.
3, RECOMPILE project generation APK:
Menu Bar->project->clean
You can run this application on V2.1 's Android system.
4. If you have a class not found error, remember to select all third party jar packages, add to build path, select the Lib directory, use as source.
Then the menu bar->project->clean

You can resolve errors that are not found by the third party jar package class.