DrawerLayout问题

Question

大家早上好，我正在试用Android Studio，我想创建一个包含谷歌地图和侧边菜单的应用程序。

起初，我集成了工作正常的卡，但是想集成侧边栏，我在主XML文件中遇到了问题。

我不理解这些错误，因为存在所谓的缺失元素

我附上了所有的错误和有问题的XML文件

提前感谢您的帮助！

所有错误-->

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.platdujourproject/com.example.platdujourproject.MainActivity}: android.view.InflateException: Binary XML file line #8: Binary XML file line #8: You must supply a layout_width attribute.
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6077)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
 Caused by: android.view.InflateException: Binary XML file line #8: Binary XML file line #8: You must supply a layout_width attribute.
 Caused by: java.lang.UnsupportedOperationException: Binary XML file line #8: You must supply a layout_width attribute.
    at android.content.res.TypedArray.getLayoutDimension(TypedArray.java:765)
    at android.view.ViewGroup$LayoutParams.setBaseAttributes(ViewGroup.java:7059)
    at android.view.ViewGroup$MarginLayoutParams.<init>(ViewGroup.java:7241)
    at androidx.constraintlayout.widget.ConstraintLayout$LayoutParams.<init>(ConstraintLayout.java:2649)
    at androidx.constraintlayout.widget.ConstraintLayout.generateLayoutParams(ConstraintLayout.java:1972)
    at androidx.constraintlayout.widget.ConstraintLayout.generateLayoutParams(ConstraintLayout.java:482)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:860)
    at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
    at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:555)
    at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:161)
    at com.example.platdujourproject.MainActivity.onCreate(MainActivity.java:52)
    at android.app.Activity.performCreate(Activity.java:6662)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6077)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)

Activity_main.xml -->

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<androidx.drawerlayout.widget.DrawerLayout
    xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:openDrawer="start">

    <include
        layout="@layout/app_bar_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <android.support.design.widget.NavigationView
        android:id="@+id/nav_view"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@menu/nav_header_main"
        app:menu="@menu/activity_main_drawer" />

</androidx.drawerlayout.widget.DrawerLayout>

<fragment
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.dell.displayinggooglemaps.MapsActivity" />
</androidx.constraintlayout.widget.ConstraintLayout>

app_bar_main.xml -->

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true"
        android:theme="@style/ThemeOverlay.AppCompat.Dark">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar_main"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Dark" />

    </android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>

activity_main_drawer.xml -->

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <group android:id="@+id/group_menu">
        <item android:id="@+id/nav_item_four"
            android:title="Item 4" />
        <item android:id="@+id/nav_item_five"
            android:title="Item 5" />
    </group>

    <item android:title="Title 1">
        <menu>
            <item android:id="@+id/nav_item_six"

                android:title="Item 6" />
            <item android:id="@+id/nav_item_seven"
                android:title="Item 7" />
        </menu>
    </item>
</menu>

nav_header_main.xml -->

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/nav_header"
    android:layout_width="match_parent"
    android:layout_height="160dp"
    android:background="@color/colorAccent"
    android:clickable="true"
    android:focusable="true"
    android:foreground="?attr/selectableItemBackgroundBorderless"
    android:gravity="bottom"
    android:orientation="vertical"
    android:padding="16dp"
    android:theme="@style/ThemeOverlay.AppCompat.Dark">

    <ImageView
        android:id="@+id/nav_header_imageView"
        android:layout_width="64dp"
        android:layout_height="64dp"
        android:src="@mipmap/ic_launcher" />

    <TextView
        android:id="@+id/nav_header_textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="16dp"
        android:text="Chike Mgbemena"
        android:textAppearance="@style/TextAppearance.AppCompat.Body1" />
</LinearLayout>

Answer 1

正如@Nikos Hidalgo提到的那样

对于某些视图，app_bar_main.xml文件中肯定缺少layout_width属性。

Answer 2

尝试从您的抽屉布局中删除xmlns:android="https://schemas.android.com/apk/res/android"，因为它已经在您的父布局中定义了。