android 打包签名时出现Conversion to Dalvik format failed

这个问题是偶发的，有时候出现，有时候不出现。

解决方案参见：http://stackoverflow.com/questions/5564816/android-export-give-a-conversion-to-dalvik-format-failed-error1

关键：

Disable "Build Automatically" on "Project Menu" and rebuild it manually (Right click on project -> Build project), then try to export the application again.译：取消”工程“菜单中的”自动编译“选项，手动编译之，而后尝试导出项目！

Eclipse seems to conflict with export and compile simultaneously. So every time you need to export an APK, disable automatic build. It's safe to use it any other time.译：Eclipse如果同时干”导出“和”编译“着两件事儿，可能会产生冲突。所以不要让他们同时干这两件事儿。