使用NavigationView，发生了一个很莫名其妙的问题。

Question

为什么我使用NavigationView，打开应用后直接显示的是侧边栏菜单里的内容，而且直接充满整个界面，怎么修改都不行。
下面是一些代码：

activity_main.xml

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

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolBar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="#5ED0FA"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            />

    </FrameLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@+id/navView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android.layout_gravity="start"
        app:menu="@menu/nav_menu"
        app:headerLayout="@layout/nav_header" />

</androidx.drawerlayout.widget.DrawerLayout>

nav_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <group android:checkableBehavior="single">
        <item
            android:id="@+id/navCall"
            android:icon="@drawable/nav_call"
            android:title="Call"/>
        <item
            android:id="@+id/navFriends"
            android:icon="@drawable/nav_friends"
            android:title="Friends"/>
        <item
            android:id="@+id/navLocation"
            android:icon="@drawable/nav_location"
            android:title="Location"/>
        <item
            android:id="@+id/navMail"
            android:icon="@drawable/nav_mail"
            android:title="Mail"/>
        <item
            android:id="@+id/navTask"
            android:icon="@drawable/nav_task"
            android:title="Tasks"/>
    </group>
</menu>

nav_header.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="180dp"
    android:padding="10dp"
    android:background="?attr/colorPrimary">

    <ImageView
        android:id="@+id/iconImage"
        android:layout_width="70dp"
        android:layout_height="70dp"
        android:src="@drawable/nav_icon"
        android:layout_centerInParent="true" />

    <TextView
        android:id="@+id/mailText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:text="[e-mail]"
        android:textColor="#FFF"
        android:textSize="14sp" />

    <TextView
        android:id="@+id/userText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@id/mailText"
        android:text="无限赫兹"
        android:textColor="#FFF"
        android:textSize="14sp" />

</RelativeLayout>

MainActivity.kt

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        setSupportActionBar(toolBar) 
        supportActionBar?.let {
            it.setDisplayHomeAsUpEnabled(true)  
            it.setHomeAsUpIndicator(R.drawable.ic_menu) 
        }
        navView.setCheckedItem(R.id.navCall)
        navView.setNavigationItemSelectedListener {
            drawerLayout.closeDrawers()
            true
        }
    }
    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
        menuInflater.inflate(R.menu.toolbar,menu)
        return true
    }
    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when(item.itemId){
            android.R.id.home -> drawerLayout.openDrawer(GravityCompat.START)
            R.id.backup -> Toast.makeText(this,"backup",Toast.LENGTH_SHORT).show()
            R.id.delete -> Toast.makeText(this,"delete",Toast.LENGTH_SHORT).show()
            R.id.settings -> Toast.makeText(this,"settings",Toast.LENGTH_SHORT).show()
        }
        return true
    }
}

Answer 1

NavigationView 宽度设置有问题，你设置成固定宽度试试