Processing annotations on Android is known to be slow.
In DroidParts each annotation has a wrapper class. The first time injection is performed on an object, annotations for it's class are read, wrapped and cached.
I've ran a micro benchmark
on an Activity with 10 TextViews in it's layout.xml.
Note that logging has to be silenced, otherwise you'll be benchmarking LogCat.
| Benchmark, 10 000 iterations | HTC Desire 2.3.7 | Galaxy Nexus 4.3 |
|---|---|---|
findViewById() |
1069ms | 524ms |
Injector.inject() |
1538ms | 690ms |
Injector.inject(), caching off |
107447ms | 43705ms |
The performance drop with annotations wrapped & cached is negligible.
Also check out this blog post.
Sometimes Eclipse doesn't update ids after Views get rearranged in a layout xml file. This results in a strange startup crash.
To fix it, run Project => Clean.