运行时异常:使用 Android 设计库

Runtime exception : using Android Design library

我收到以下错误:

07-01 09:02:19.285    7395-7395/com.chitechnolabs.android.droidrestclient E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.chitechnolabs.android.droidrestclient, PID: 7395
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.chitechnolabs.android.droidrestclient/com.chitechnolabs.android.droidrestclient.SplashActivity}: android.view.InflateException: Binary XML file line #36: Error inflating class ViewPager
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access0(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: android.view.InflateException: Binary XML file line #36: Error inflating class ViewPager
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:757)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
            at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:249)
            at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:106)
            at com.chitechnolabs.android.droidrestclient.SplashActivity.onCreate(SplashActivity.java:44)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access0(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.ViewPager" on path: DexPathList[[zip file "/data/app/com.chitechnolabs.android.droidrestclient-1/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
            at android.view.LayoutInflater.createView(LayoutInflater.java:571)
            at android.view.LayoutInflater.onCreateView(LayoutInflater.java:665)
            at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:65)
            at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:806)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.rInflate(LayoutInflater.java:809)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
            at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:249)
            at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:106)
            at com.chitechnolabs.android.droidrestclient.SplashActivity.onCreate(SplashActivity.java:44)
            at android.app.Activity.performCreate(Activity.java:5933)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access0(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
    Suppressed: java.lang.ClassNotFoundException: android.view.ViewPager
            at java.lang.Class.classForName(Native Method)
            at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
            at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
            ... 28 more
     Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack available

我在尝试将 ViewPager 放入 CoordinatorLayout 时遇到此错误。我按照本教程使用设计库:http://inthecheesefactory.com/blog/android-design-support-library-codelab/en

我是这样使用的:

<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.support.design.widget.CoordinatorLayout
        android:id="@+id/rootLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.design.widget.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

            <android.support.design.widget.TabLayout
                android:id="@+id/tabLayout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

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

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <ViewPager
                android:id="@+id/viewPager"
                android:layout_width="match_parent"
                android:layout_height="match_parent" />
        </LinearLayout>


        <android.support.design.widget.FloatingActionButton
            android:id="@+id/fabBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom|right"
            android:layout_marginBottom="@dimen/codelab_fab_margin_bottom"
            android:layout_marginRight="@dimen/codelab_fab_margin_right"
            android:src="@drawable/ic_plus"
            app:fabSize="normal" />

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

    <android.support.design.widget.NavigationView
        android:id="@+id/navigation"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:headerLayout="@layout/nav_header"
        app:itemIconTint="#333"
        app:itemTextColor="#333"
        app:menu="@menu/navigation_drawer_items" />

</android.support.v4.widget.DrawerLayout>

这是我的 activity 代码:

public class SplashActivity extends AppCompatActivity{

    private FloatingActionButton fabBtn;
    private CoordinatorLayout rootLayout;
    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;
    private NavigationView navigation;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_splash);

        initInstances();
    }

    private void initInstances() {
        fabBtn = (FloatingActionButton) findViewById(R.id.fabBtn);
        fabBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Snackbar.make(rootLayout, "Hello. I am Snackbar!", Snackbar.LENGTH_SHORT)
                        .setAction("Undo", new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {

                            }
                        })
                        .show();
            }
        });

        rootLayout = (CoordinatorLayout) findViewById(R.id.rootLayout);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        tabLayout = (TabLayout) findViewById(R.id.tabLayout);
        tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
        tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
        tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
        tabLayout.setupWithViewPager(viewPager);

        navigation = (NavigationView) findViewById(R.id.navigation);
        navigation.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(MenuItem menuItem) {
                int id = menuItem.getItemId();
                switch (id) {
                    case R.id.navItem1:
                        break;
                    case R.id.navItem2:
                        break;
                    case R.id.navItem3:
                        break;
                }
                return false;
            }
        });

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_splash, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

在您的布局中,您必须更改此部分:

<android.support.v4.view.ViewPager
           android:id="@+id/viewPager"
           android:layout_width="match_parent"
           android:layout_height="match_parent" />

而不是

<ViewPager ..../>

由于 class 未找到,这显然是布局膨胀错误。

你必须改变

ViewPager

<android.support.v4.view.ViewPager
       android:id="@+id/viewPager"
       android:layout_width="match_parent"
       android:layout_height="match_parent" />