这是造成问题的布局。
<?xml version="1.0" encoding="utf-8"?>
<!-- Drawer Layout -->
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/drawer_layout"
android:fitsSystemWindows="true">
<!--Main content-->
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/mtoolbar"
android:minHeight="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:layout_width="match_parent"
app:theme="@style/ThemeOverlay.AppCompat.Dark"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
android:layout_height="wrap_content">
</android.support.v7.widget.Toolbar>
<TextView
android:text="@string/hello_world"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/mtoolbar"
android:layout_centerInParent="true"/>
</RelativeLayout>
<!--Navigation Drawer-->
<android.support.design.widget.NavigationView
android:id="@+id/main_drawer"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
app:headerLayout="@layout/drawer_header"
app:menu="@menu/menu_drawer"/>
</android.support.v4.widget.DrawerLayout>
以下是drawer_header.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="150dp"
android:background="@drawable/header"
android:padding="16dp"
android:orientation="vertical"
android:gravity="bottom">
<TextView
android:textColor="#ffffff"
android:textSize="18sp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Hello World "
/>
</LinearLayout>
这里是logcat输出
06-15 21:38:05.125 14798 14798 I art Late-enabling -Xcheck:jni
06-15 21:38:05.323 14798 14798 W System ClassLoader referenced unknown path: /data/app/xyz.sayangoswami.opoforums-2/lib/arm
06-15 21:38:05.472 14798 14798 I AppCompatViewInflater app:theme is now deprecated. Please move to using android:theme instead.
06-15 21:38:05.515 14798 14798 D AndroidRuntime Shutting down VM
06-15 21:38:05.520 14798 14798 E AndroidRuntime FATAL EXCEPTION: main
06-15 21:38:05.520 14798 14798 E AndroidRuntime Process: xyz.sayangoswami.opoforums, PID: 14798
06-15 21:38:05.520 14798 14798 E AndroidRuntime java.lang.RuntimeException: Unable to start activity ComponentInfo{xyz.sayangoswami.opoforums/xyz.sayangoswami.opoforums.MainActivity}: android.view.InflateException: Binary XML file line #39: Binary XML file line #39: Error inflating class android.support.design.widget.NavigationView
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread.-wrap11(ActivityThread.java)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.os.Handler.dispatchMessage(Handler.java:102)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.os.Looper.loop(Looper.java:148)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread.main(ActivityThread.java:5417)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at java.lang.reflect.Method.invoke(Native Method)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
06-15 21:38:05.520 14798 14798 E AndroidRuntime Caused by: android.view.InflateException: Binary XML file line #39: Binary XML file line #39: Error inflating class android.support.design.widget.NavigationView
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:280)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at xyz.sayangoswami.opoforums.MainActivity.onCreate(MainActivity.java:28)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.Activity.performCreate(Activity.java:6251)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
06-15 21:38:05.520 14798 14798 E AndroidRuntime ... 9 more
06-15 21:38:05.520 14798 14798 E AndroidRuntime Caused by: android.view.InflateException: Binary XML file line #39: Error inflating class android.support.design.widget.NavigationView
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.createView(LayoutInflater.java:645)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:764)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:704)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.rInflate(LayoutInflater.java:835)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:798)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
06-15 21:38:05.520 14798 14798 E AndroidRuntime ... 17 more
06-15 21:38:05.520 14798 14798 E AndroidRuntime Caused by: java.lang.reflect.InvocationTargetException
06-15 21:38:05.520 14798 14798 E AndroidRuntime at java.lang.reflect.Constructor.newInstance(Native Method)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.createView(LayoutInflater.java:619)
06-15 21:38:05.520 14798 14798 E AndroidRuntime ... 22 more
06-15 21:38:05.520 14798 14798 E AndroidRuntime Caused by: android.view.InflateException: Binary XML file line #2: Binary XML file line #2: You must supply a layout_width attribute.
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:539)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.design.internal.NavigationMenuPresenter.inflateHeaderView(NavigationMenuPresenter.java:189)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.design.widget.NavigationView.inflateHeaderView(NavigationView.java:263)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.design.widget.NavigationView.<init>(NavigationView.java:174)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.support.design.widget.NavigationView.<init>(NavigationView.java:96)
06-15 21:38:05.520 14798 14798 E AndroidRuntime ... 24 more
06-15 21:38:05.520 14798 14798 E AndroidRuntime Caused by: java.lang.UnsupportedOperationException: Binary XML file line #2: You must supply a layout_width attribute.
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.content.res.TypedArray.getLayoutDimension(TypedArray.java:709)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.ViewGroup$LayoutParams.setBaseAttributes(ViewGroup.java:6889)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.ViewGroup$MarginLayoutParams.<init>(ViewGroup.java:7071)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.widget.LinearLayout$LayoutParams.<init>(LinearLayout.java:1911)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.widget.LinearLayout.generateLayoutParams(LinearLayout.java:1816)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.widget.LinearLayout.generateLayoutParams(LinearLayout.java:1815)
06-15 21:38:05.520 14798 14798 E AndroidRuntime at android.view.LayoutInflater.inflate(LayoutInflater.java:502)
06-15 21:38:05.520 14798 14798 E AndroidRuntime ... 29 more
虽然我已经为DrawerLayout提供了layout_width参数，但它仍然显示错误。
如果有帮助，我将使用AppCompat v7和Design支持库以及compileSdkVersion 21和buildToolsVersion 21.1.0
提前致谢。
问题是我在http://schemas.android.com/apk/res/android第2行的HTTP://SCHEMAS.ANDROID.COM/APK/RES/ANDROID大写drawer_header.xml。
答案 0 :(得分：2)
您应该在drawer_header.xml文件中看到错误，名称空间不应全部为大写：
xmlns:android="http://schemas.android.com/apk/res/android"
不
xmlns:android="HTTP://SCHEMAS.ANDROID.COM/APK/RES/ANDROID"