一般來說，常用的android設計模式有以下8種：單例、工廠、觀察者、代理、命令、介面卡、合成、訪問者。

　　單例模式：目的是為了讓系統中只有一個呼叫物件，缺點是單例使其他程式過分依賴它，而且不同單例執行在不同程序中，使得維護困難；

　　工廠模式：生產固定的一些東西，如抽象類，缺點是產品修改麻煩；如喜歡動作片和愛情片的人分別向伺服器發出同一個請求，就可以得到他們想看的影片集，相當於不同物件進行同一請求，需求均得到滿足。

      AOSP中使用到工廠模式的地方：

1. Java中的工廠方法：

2. java.net.DatagramSocketImplFactory

3. java.net.SocketImplFactory

4. java.net.URLStreamHandlerFactory

5. java.security.cert.CertificateFactory

6. java.util.prefs.PreferencesFactory

7. javax.xml.parsers.SAXParserFactory

8. SSLSocketFactory

9. LogFactory

10. AuthSchemeFactory

11. SocketFactory

12. MultihomePlainSocketFactory

13. LayeredSocketFactory

14. PlainSocketFactory

15. CookieSpecFactory

16. HttpRequestFactory

17. HttpResponseFactory

18. ClientConnectionManagerFactory

19. XMLStringFactory

20. lookUpFactoryClass

21. DocumentBuilderFactory

22. IntentFactory

23. SQLiteDatabase.CursorFactory

24. RemoteViewsFactory

25. EffectFactory

26. CodecFactory

27. EGLContextFactory

28. SAXParserFactory

29. Spannable.Factory

30. MockEditableFactory

31. TransformerFactory

32. IApiLoader

33. TypePool

34. ITypeFactory

35. org.xmlpull.v1.XmlPullParserFactory

36. ContextFactory

37. LayoutInflater

38. CardViewFragment

39. NFAFactory

40. ExecutorFactory

41.  

42. C/C++中的工廠方法：

43.  

44. AudioSignalFactory

45. GenericFactory

46. EmulatedCameraFactory

47. ANTLR3_TOKEN_FACTORY

48. JniDependencyFactory

49. WeakPtrFactory

50. scheme_classifier_factory

51. content_activity_factory

52. activity_factory

53. pref_service_factory

54. MessagePumpFactory

55. surface_factory

56. LayerTreeHostFactory

57. SurfaceFactory

58. DriveIntegrationServiceFactory

59. ServiceFactory

60. devtools_network_transaction_factory

61. MockDistillerFactory

62. MockDistillerPageFactory

63. BrowserContextKeyedAPIFactory

64. PickerFactory

65. URLFetcherImplFactory

66. BrowserContextKeyedAPIFactory

67. chrome/browser/extensions/api/dial/dial_api_factory.h

68. chrome/browser/extensions/api/idle/idle_manager_factory.h

69. chrome/browser/extensions/api/networking_private/networking_private_event_router_factory.h

70. chrome/browser/extensions/extension_garbage_collector_factory.h

71. chrome/browser/extensions/extension_storage_monitor_factory.h

72. chrome/browser/extensions/extension_system_factory.h

73. chrome/browser/extensions/extension_toolbar_model_factory.h

74. chrome/browser/extensions/install_tracker_factory.h

75. chrome/browser/extensions/menu_manager_factory.h

76. chrome/browser/extensions/token_cache/token_cache_service_factory.h

77. chrome/browser/chromeos/extensions/file_manager/event_router_factory.h

78. chrome/browser/signin/chrome_signin_client_factory.h

79. chrome/browser/signin/chrome_signin_client_factory.h

80. chrome/browser/signin/signin_manager_factory.h

81. chrome/browser/invalidation/profile_invalidation_provider_factory.h

82. chrome/browser/services/gcm/gcm_profile_service_factory.h

83. chrome/browser/net/proxy_service_factory.h

84. chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings_factory.h

85. content/public/browser/cookie_store_factory.h

86. net/http/http_auth_handler_factory.h

87. net/url_request/url_request_job_factory_impl.h

88. PrivetHTTPAsynchronousFactory

89. chrome/browser/search/hotword_service_factory.h

90. chrome/browser/search_engines/template_url_service_factory.h

91. chrome/browser/search_engines/template_url_fetcher_factory.h

92. components/gcm_driver/gcm_client_factory.h

93. chrome/browser/supervised_user/supervised_user_service_factory.h

94. chrome/browser/signin/profile_oauth2_token_service_factory.h

95. chrome/browser/supervised_user/custodian_profile_downloader_service_factory.h

96. chrome/browser/supervised_user/supervised_user_pref_mapping_service_factory.h

97. chrome/browser/supervised_user/supervised_user_settings_service_factory.h

98. chrome/browser/supervised_user/supervised_user_shared_settings_service_factory.h

99. chrome/browser/supervised_user/supervised_user_sync_service_factory.h

100. chrome/browser/sync/profile_sync_service_factory.h

101. chrome/browser/themes/theme_service_factory.h

102. chrome/browser/bookmarks/bookmark_model_factory.h

103. chrome/browser/dom_distiller/dom_distiller_service_factory.h

104. chrome/browser/history/history_service_factory.h

105. chrome/browser/notifications/sync_notifier/chrome_notifier_service_factory.h

106. chrome/browser/password_manager/password_store_factory.h

107. chrome/browser/search_engines/template_url_service_factory.h

108. chrome/browser/signin/signin_manager_factory.h

109. chrome/browser/sync/profile_sync_components_factory_impl.h

110. chrome/browser/webdata/web_data_service_factory.h

111. chrome/browser/ui/app_list/app_list_syncable_service_factory.h

112. chrome/browser/spellchecker/spellcheck_factory.h

113. content/common/gpu/gpu_memory_buffer_factory.h

114. content/renderer/android/synchronous_compositor_factory.cc

115. mojo/services/public/cpp/view_manager/view_manager_client_factory.h

                   太多了，比想辦法羅列完，有一個更急迫的問題：如何消滅程式設計師？

　　觀察者模式：就是多個物件對一個物件進行監控，如快取；

　　代理模式：自己的事交給別人去做，分別返回結果即可，如非同步執行緒；

　　命令模式：呼叫物件與作用物件之間分離，由中介軟體來協調兩者之間的工作，如控制器；

　　介面卡模式：將一個介面變成使用者所需要的介面，如baseadapter可以適配listview和spinner，因為它們有相同的介面

　　合成模式：將一對多的關係轉換成一對整體的關係，如listview與介面卡；

      建造者模式：AlertDialog.Builder