Java 如何在AndroidStudio 3.6.1中可视化底部导航栏和带有片段的抽屉_Java_Android_Android Fragments_Navigation Drawer_Bottomnavigationview

Java 如何在AndroidStudio 3.6.1中可视化底部导航栏和带有片段的抽屉

java android android-fragments

Java 如何在AndroidStudio 3.6.1中可视化底部导航栏和带有片段的抽屉,java,android,android-fragments,navigation-drawer,bottomnavigationview,Java,Android,Android Fragments,Navigation Drawer,Bottomnavigationview,我所做的：我添加了导航抽屉和底部导航栏，如下所示，并希望两者都起作用。但当我试着运行它时，它说原因：java.lang.ClassCastException:android.widget.RelativeLayout无法强制转换为androidx.drawerlayout.widget.drawerlayout main.xml： <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:androi

我所做的： 我添加了导航抽屉和底部导航栏，如下所示，并希望两者都起作用。但当我试着运行它时，它说

原因：java.lang.ClassCastException:android.widget.RelativeLayout无法强制转换为androidx.drawerlayout.widget.drawerlayout

main.xml：

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".MainActivity"
    tools:openDrawer="start">


    <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/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/navigationView" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/navigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/colorAccent"
        app:itemBackground="?selectableItemBackgroundBorderless"
        app:itemHorizontalTranslationEnabled="true"
        app:itemIconTint="@drawable/nav_item_color_state"
        app:itemTextColor="@drawable/nav_item_color_state"
        app:menu="@menu/bottom_nav" />


    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/drawer_menu"

        />


</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".MainActivity"
    tools:openDrawer="start">

<RelativeLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <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/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/navigationView" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/navigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/colorAccent"
        app:itemBackground="?selectableItemBackgroundBorderless"
        app:itemHorizontalTranslationEnabled="true"
        app:itemIconTint="@drawable/nav_item_color_state"
        app:itemTextColor="@drawable/nav_item_color_state"
        app:menu="@menu/bottom_nav" />

</RelativeLayout>

    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/drawer_menu"

        />


</androidx.drawerlayout.widget.DrawerLayout>

然后我在上面更改为：相对布局被删除并替换为“抽屉布局”，但现在编译时没有错误，但我只能在全屏上看到导航抽屉，而不能看到底部导航栏、工具栏或片段

编辑的main.xml：

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".MainActivity"
    tools:openDrawer="start">


    <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/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/navigationView" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/navigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/colorAccent"
        app:itemBackground="?selectableItemBackgroundBorderless"
        app:itemHorizontalTranslationEnabled="true"
        app:itemIconTint="@drawable/nav_item_color_state"
        app:itemTextColor="@drawable/nav_item_color_state"
        app:menu="@menu/bottom_nav" />


    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/drawer_menu"

        />


</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".MainActivity"
    tools:openDrawer="start">

<RelativeLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <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/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/navigationView" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/navigationView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/colorAccent"
        app:itemBackground="?selectableItemBackgroundBorderless"
        app:itemHorizontalTranslationEnabled="true"
        app:itemIconTint="@drawable/nav_item_color_state"
        app:itemTextColor="@drawable/nav_item_color_state"
        app:menu="@menu/bottom_nav" />

</RelativeLayout>

    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/drawer_menu"

        />


</androidx.drawerlayout.widget.DrawerLayout>

我真的很感激任何改善这一点的建议。谢谢大家!