我遇到这个问题已有一段时间了
我相信这是因为，即使我跟随开发人员网站来实现它，也不是因为抽屉布局实现有些不正确。
我有一个活动，目前有3个帧，mangaSearch（mS）（recyclerView），配置文件，设置 mS是开始片段，当我进入抽屉菜单并选择配置文件或设置时，片段会绘制在mS片段上方。当我回击时，mS片段再次按预期显示为正常。
我在google / stack上环顾了一下，但是没有找到解决此问题的方法，因此我在这里寻求帮助。
更新 我在抽屉中输入了错误的ID，我不得不将其更改为导航nav_graph布局中的ID。
mainActivity
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.view.GravityCompat;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.navigation.NavController;
import androidx.navigation.Navigation;
import androidx.navigation.ui.AppBarConfiguration;
import androidx.navigation.ui.NavigationUI;
import android.os.Bundle;
import android.view.MenuItem;
import android.widget.Toast;
import com.google.android.material.navigation.NavigationView;
import Classes.LoggedInUser;
public class MainActivity extends AppCompatActivity {
private DrawerLayout drawer;
private AppBarConfiguration appBarConfig;
public static LoggedInUser loggedInUser;
FragmentManager fm;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
loggedInUser = LoggedInUser.getInstance();
fm = getSupportFragmentManager();
androidx.appcompat.widget.Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
drawer = findViewById(R.id.drawer_layout);
appBarConfig = new AppBarConfiguration.Builder(R.id.nav_graph_manga_book_details,
R.id.nav_graph_mangas_search_souce, R.id.nav_graph_profile,
R.id.nav_graph_settings).setDrawerLayout(drawer).build();
NavController navController = Navigation.findNavController(this, R.id.main_content);
NavigationView navigationView = findViewById(R.id.nav_view);
NavigationUI.setupActionBarWithNavController(this, navController, appBarConfig);
//NavigationUI.setupWithNavController(navigationView, navController);
DrawerLayout drawerL = findViewById(R.id.drawer_layout);
NavigationUI.setupActionBarWithNavController(this, navController, drawerL);
NavigationUI.setupWithNavController(navigationView, navController);
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.nav_manga_books_source:
fm.beginTransaction().replace(R.id.main_content, new MangasSearchFragment(), "mangaBookSource").commit();
break;
case R.id.nav_user_profile:
//check if person is logged in?
fm.beginTransaction().replace(R.id.main_content, new ProfileFragment(), "profile").commit();
break;
case R.id.nav_settings:
fm.beginTransaction().replace(R.id.main_content, new SettingsFragment(), "settings").commit();
break;
case R.id.nav_settings_temp:
Toast.makeText(MainActivity.this, "Settings Temp works", Toast.LENGTH_SHORT).show();
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
});
}
@Override
public boolean onSupportNavigateUp() {
NavController navController = Navigation.findNavController(this, R.id.main_content);
return NavigationUI.navigateUp(navController, appBarConfig) || super.onSupportNavigateUp();
}
@Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
}
else {
super.onBackPressed();
}
}
}
布局文件
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:orientation="vertical"
tools:openDrawer="start">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<fragment
android:id="@+id/main_content"
android:name="androidx.navigation.fragment.NavHostFragment"
app:navGraph="@navigation/navigation_graph"
app:defaultNavHost="true"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
</LinearLayout>
<com.google.android.material.navigation.NavigationView
android:id="@+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:headerLayout="@layout/nav_header"
app:menu="@menu/drawer_menu" />
</androidx.drawerlayout.widget.DrawerLayout>
布局抽屉菜单
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
tools:showIn="navigation_view">
<group android:checkableBehavior="single">
<item
android:id="@+id/nav_user_profile"
android:icon="@drawable/ic_user_profile"
android:title="Profile" />
<item
android:id="@+id/nav_manga_books_source"
android:icon="@drawable/ic_manga_books_of_source"
android:title="Manga's"/>
<item
android:id="@+id/nav_settings"
android:icon="@drawable/ic_settings"
android:title="Settings"/>
</group>
<item android:title="new group">
<menu>
<item
android:id="@+id/nav_settings_temp"
android:icon="@drawable/ic_settings"
android:title="Settings temp" />
</menu>
</item>
</menu>
后来有人推荐的导航组件。问题已经存在，并且不能解决，因为它不是要解决的，但可能与mainActivity代码有关
<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/mobile_navigation"
app:startDestination="@+id/nav_graph_mangas_search_souce">
<fragment
android:id="@+id/nav_graph_mangas_search_souce"
android:name="com.example.what2watchmangareader.MangasSearchFragment"
android:label="start fragment"
tools:layout="@layout/fragment_mangas_to_search" />
<fragment
android:id="@+id/nav_graph_profile"
android:name="com.example.what2watchmangareader.ProfileFragment"
android:label="profile page"
tools:layout="@layout/fragment_profile" />
<fragment
android:id="@+id/nav_graph_settings"
android:name="com.example.what2watchmangareader.SettingsFragment"
android:label="Settings Page"
tools:layout="@layout/fragment_settings" />
<fragment
android:id="@+id/nav_graph_manga_book_details"
android:name="com.example.what2watchmangareader.MangaBookFragment"
android:label="Manga detail"
tools:layout="@layout/fragment_manga_book_info" />
//Add your other fragments here.
</navigation>
答案 0 :(得分：0)
根据documentation，使用OnNavigationItemSelectedListener时不需要运行任何FragmentTransactions，也不需要手动实现setupWithNavController()。相反，您只需要在导航图和菜单项之间匹配android:id。