Question

应用程序和工具栏在纵向模式下工作正常，但只要我将其设置为横向模式，应用程序就会崩溃。

这是logcat

Caused by: java.lang.NullPointerException
at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:94)
at android.support.v7.internal.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:87)
at android.support.v7.internal.app.ToolbarActionBar.<init>(ToolbarActionBar.java:77)
at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:198)
at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:96)
at maxbleggi.afstudentplanner.activities.MainActivity.onCreate(MainActivity.java:104)
at android.app.Activity.performCreate(Activity.java:5323)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2302)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3930)
at android.app.ActivityThread.access$900(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1327)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5292)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
at dalvik.system.NativeStart.main(Native Method)

这是我的工具栏（tool_bar.xml）

<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/primary"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark"
android:popupTheme="@style/ThemeOverlay.AppCompat.Light"
android:fitsSystemWindows="true"
xmlns:android="http://schemas.android.com/apk/res/android">
</android.support.v7.widget.Toolbar>

这是我的活动主要

<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"
android:fitsSystemWindows="true">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <include
        android:id="@+id/tool_bar"
        layout="@layout/tool_bar">
    </include>

    <FrameLayout
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </FrameLayout>

</LinearLayout>

<android.support.design.widget.NavigationView
    android:id="@+id/navigation_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:headerLayout="@layout/drawer_header"
    app:menu="@menu/drawer"/>

这是抛出异常的代码行

// initialise and set toolbar as actionbar
toolbar = (Toolbar) findViewById(R.id.tool_bar);
setSupportActionBar(toolbar);

和

maxbleggi.afstudentplanner.activities.MainActivity.onCreate(MainActivity.java:104)

具体是这一行

 setSupportActionBar(toolbar);

设置为横向时，工具栏中的空指针异常

0 个答案: