在Android菜单资源中，android：menuCategory属性是否存在有什么区别？
我阅读了文档并创建了一些小测试代码，但我无法理解这个属性和常量的含义。
答案 0 :(得分：0)
通过使用android：menuCategory标签，您可以指定菜单项组的类别并定义项目的优先级。
答案 1 :(得分：0)
我不知道 version: "3"
services:
namenode:
image: bde2020/hadoop-namenode:2.0.0-hadoop3.2.1-java8
container_name: namenode
restart: always
ports:
- 9870:9870
- 9000:9000
volumes:
- hadoop_namenode:/hadoop/dfs/name
environment:
- CLUSTER_NAME=test
env_file:
- ./hadoop.env
datanode1:
image: bde2020/hadoop-datanode:2.0.0-hadoop3.2.1-java8
container_name: datanode1
restart: always
volumes:
- hadoop_datanode1:/hadoop/dfs/data
environment:
SERVICE_PRECONDITION: "namenode:9870"
env_file:
- ./hadoop.env
datanode2:
image: bde2020/hadoop-datanode:2.0.0-hadoop3.2.1-java8
container_name: datanode2
restart: always
volumes:
- hadoop_datanode2:/hadoop/dfs/data
environment:
SERVICE_PRECONDITION: "namenode:9870"
env_file:
- ./hadoop.env
datanode3:
image: bde2020/hadoop-datanode:2.0.0-hadoop3.2.1-java8
container_name: datanode3
restart: always
volumes:
- hadoop_datanode3:/hadoop/dfs/data
environment:
SERVICE_PRECONDITION: "namenode:9870"
env_file:
- ./hadoop.env
resourcemanager:
image: bde2020/hadoop-resourcemanager:2.0.0-hadoop3.2.1-java8
container_name: resourcemanager
restart: always
environment:
SERVICE_PRECONDITION: "namenode:9000 namenode:9870 datanode1:9864 datanode2:9864"
env_file:
- ./hadoop.env
nodemanager1:
image: bde2020/hadoop-nodemanager:2.0.0-hadoop3.2.1-java8
container_name: nodemanager
restart: always
environment:
SERVICE_PRECONDITION: "namenode:9000 namenode:9870 datanode1:9864 datanode2:9864 resourcemanager:8088"
env_file:
- ./hadoop.env
historyserver:
image: bde2020/hadoop-historyserver:2.0.0-hadoop3.2.1-java8
container_name: historyserver
restart: always
environment:
SERVICE_PRECONDITION: "namenode:9000 namenode:9870 datanode1:9864 datanode2:9864 resourcemanager:8088"
volumes:
- hadoop_historyserver:/hadoop/yarn/timeline
env_file:
- ./hadoop.env
volumes:
hadoop_namenode:
hadoop_datanode1:
hadoop_datanode2:
hadoop_datanode3:
hadoop_historyserver:
的确切用例，但我在有 HomeFragment 的项目中使用了它，我可以从它转到 LoginFragment。在 LoginFragment 中，我有一个菜单（在右上角）用于转到 SettingsFragment。
当我进入设置并返回时，它返回主页而不是登录页面。但我希望它返回之前的位置（登录页面）。因此我使用了 menuCategory，并且它起作用了
menuCategory