为什么总是编译不了APK?下载了JAVA SDK并复制build.xml到F:\RainbowEngineAndroid\tools\ant里,居然还有下列错误代码: Buildfile: C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\And302.tmp\build.xml [echo] Please set the environment variable ANT_OPTS to -Xmx256m [taskdef] Could not load definitions from resource flexTasks.tasks. It could not be found. BUILD FAILED Target "debug" does not exist in the project "RuntimeAndroid". Total time: 1 second 请问这是怎么回事?