Android modification does not work, or minor modification causes layout disorder or even inexplicable exceptions.

I have encountered some inexplicable situations in my work recently. I don't know if I have met anyone. I made a small modification to a layout xml file. As a result, the entire interface is completely unsightly and has no logic. You can troubleshoot code issues multiple times. On one occasion, I just repaired the android: background of a control. As a result, multiple irrelevant pages report nullpointerexception, ClassCastException, and so on. Both on the simulator and on the real machine, restarting eclipse does not help. After several attempts, it is preliminarily determined that it is ide or adt intermittent extraction. The following are my summary methods. 1. delete some files in the bin directory and run them. In this way, the vast majority of "changes do not work" can be solved. 2. Withdraw the modification and run it once. Then modify the file and run it again. It can solve other situations.