Question

我正在尝试从Android Architecture Components实现Nagivation。我能够成功浏览片段。我正在尝试将其附加到我的底部导航中，但无法正确使用它。我可以使用Navigation.findNavController(View).navigate(R.id.Fragment)成功地在片段之间导航，但是当我使用任何UI组件或后退按钮进行导航时，底部导航中的高亮显示并没有发生变化，如下图gif所示。

我对MainActivity.kt的代码如下，

class MainActivity : AppCompatActivity() {


    private lateinit var navController: NavController


    private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
        when (item.itemId) {
            R.id.navigation_home -> {
                navController.navigate(R.id.homeFragment)
                return@OnNavigationItemSelectedListener true
            }
            R.id.navigation_dashboard -> {
                navController.navigate(R.id.addEmotionFragment)
                return@OnNavigationItemSelectedListener true
            }
            R.id.navigation_notifications -> {
                return@OnNavigationItemSelectedListener true
            }
        }
        false
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        navController = Navigation.findNavController(this, R.id.nav_host)
        navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)
    }


}

对于HomeFragment.kt

class HomeFragment : Fragment() {

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_home, container, false)
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)

        button.setOnClickListener {
            Navigation.findNavController(it).navigate(R.id.addEmotionFragment)
        }
    }
}

Answer 1

尝试使用导航用户界面。

implementation 'androidx.navigation:navigation-ui:' + navigationVersion //currently 1.0.0-alpha05

活动

    navController = Navigation.findNavController(this, R.id.nav_host)
    NavigationUI.setupWithNavController(bottomNavigation, navController)

并确保您的片段ID与菜单ID相匹配。

<item
        android:id="@+id/homeFragment"
        android:title="Home"/>

Answer 2

您需要在按钮内部手动设置选中的属性，例如：

DSLContext ctx;

String createTableSql = ctx.createTable("TABLE_NAME")
        .column("TABLE_ID", SQLDataType.BIGINT.identity(true))
        .column("COL_1", SQLDataType.VARCHAR(64).nullable(false))
        .constraints(
            DSL.constraint("PK_TABLE").primaryKey("TABLE_ID"),
            DSL.constraint("UNIQUE_COL_1").unique("COL_1")
        ).getSQL();

System.out.println(createTableSql);

Java代码为：

create table `TABLE_NAME`( `TABLE_ID` bigint not null auto_increment, `COL_1` varchar(64) not null, constraint `PK_TABLE` primary key (`TABLE_ID`), constraint `UNIQUE_COL_1` unique (`COL_1`) )

Android BottomNavigation无法使用导航控制器正确突出显示

2 个答案: