Android错误java.lang.NullPointerException:尝试调用虚拟方法';void androidx.appcompat.app.ActionBar.setTitle
我是Android新手。它在底部导航时显示错误 错误: Android错误java.lang.NullPointerException:尝试调用虚拟方法“void androidx.appcompat.app.ActionBar.setTitle”Android错误java.lang.NullPointerException:尝试调用虚拟方法';void androidx.appcompat.app.ActionBar.setTitle,android,Android,我是Android新手。它在底部导航时显示错误 错误: Android错误java.lang.NullPointerException:尝试调用虚拟方法“void androidx.appcompat.app.ActionBar.setTitle” @凌驾 创建时受保护的void(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity\u主页); Botto
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u主页);
BottomNavigationView-navView=findViewById(R.id.nav_视图);
//将每个菜单ID作为一组ID传递,因为每个
//菜单应被视为顶级目的地。
AppBarConfiguration AppBarConfiguration=新建AppBarConfiguration.Builder(
R.id.navigation\u主页、R.id.navigation\u仪表板、R.id.navigation\u通知)
.build();
NavController NavController=Navigation.findNavController(这个,R.id.nav_主机_片段);
NavigationUI.setupActionBarWithNavController(此、navController、appBarConfiguration);
NavigationUI.setupWithNavController(navView、navController);
}
如果要显示无标题屏幕,首先应删除navigation.xml中的安卓:标签:
<fragment
android:id="@+id/navigation_home"
android:label="HomeFragment" //remove this line
android:name="com.shiwei.fly.ui.home.HomeFragment" />
这回答了你的问题吗?第27行是什么?我很抱歉写错了看到这个:
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
/*val appBarConfiguration = AppBarConfiguration(setOf(
R.id.navigation_home, R.id.navigation_dashboard, R.id.navigation_notifications))
setupActionBarWithNavController(navController, appBarConfiguration)*/