我有使用片段的滑动视图的应用程序。我想要的是为每个片段创建单独的工具栏。香港专业教育学院搜索互联网并使用推荐的解决方案，但当我想使用setSupportActionBar（）时，当我尝试将MainActivity强制转换为AppCompact Activity时，我的应用程序崩溃了。继承人片段类：
package sk.cassomedia.studentassitent.view;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import sk.cassomedia.studentassitent.R;
public class Contacts extends Fragment {
private Toolbar toolbar;
public Contacts() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_contacts, container, false);
AppCompatActivity activity = (AppCompatActivity) getActivity();
toolbar = (Toolbar) view.findViewById(R.id.contacts_toolbar);
activity.setSupportActionBar(toolbar);
return view;
}
public boolean onCreateOptionsMenu(Menu menu) {
getActivity().getMenuInflater().inflate(R.menu.calendar_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
public static Fragment newInstance() {
Contacts contacts = new Contacts();
return contacts;
}
}
继承片段布局：
<RelativeLayout 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="sk.cassomedia.studentassitent.view.Contacts">
<include
android:id="@+id/contacts_toolbar"
layout="@layout/contacts_toolbar"></include>
<ListView
android:layout_width="wrap_content"
android:layout_height="836dp"
android:id="@+id/listView"
android:layout_gravity="center_horizontal|bottom" />
</RelativeLayout>
和工具栏xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimary"
android:elevation="4dp">
</android.support.v7.widget.Toolbar>
错误消息
02-22 09:09:07.835 12623-12623/sk.cassomedia.studentassitent E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.ClassCastException: sk.cassomedia.studentassitent.MainActivity cannot be cast to android.support.v7.app.ActionBarActivity
at sk.cassomedia.studentassitent.view.Contacts.onCreateView(Contacts.java:30)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager$3.run(ViewPager.java:251)
at android.support.v4.view.ViewPager.completeScroll(ViewPager.java:1849)
at android.support.v4.view.ViewPager.onInterceptTouchEvent(ViewPager.java:1978)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2033)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2306)
at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1575)
at android.app.Activity.dispatchTouchEvent(Activity.java:2470)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2254)
at android.view.View.dispatchPointerEvent(View.java:7888)
at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3977)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3861)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5101)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5080)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5179)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:125)
at android.os.Looper.loop(Looper.java:138)
at android.app.ActivityThread.main(ActivityThread.java:5365)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
styles.xml
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
MainActivity
package sk.cassomedia.studentassitent;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import sk.cassomedia.studentassitent.controllers.FragmentAdapter;
public class MainActivity extends FragmentActivity {
static final int NUMBER_OF_SCREENS = 3;
private FragmentAdapter adapter;
private ViewPager viewPage;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
adapter = new FragmentAdapter(getSupportFragmentManager());
viewPage = (ViewPager) findViewById(R.id.pager);
viewPage.setAdapter(adapter);
}
}
如果我更改主要活动以扩展AppCompat活动
，则记录消息02-22 09:15:26.757 14192-14192/sk.cassomedia.studentassitent E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.ClassCastException: sk.cassomedia.studentassitent.MainActivity cannot be cast to android.support.v7.app.ActionBarActivity
at sk.cassomedia.studentassitent.view.Contacts.onCreateView(Contacts.java:30)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1067)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1248)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:738)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1613)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1106)
at android.support.v4.view.ViewPager.populate(ViewPager.java:952)
at android.support.v4.view.ViewPager$3.run(ViewPager.java:251)
at android.support.v4.view.ViewPager.completeScroll(ViewPager.java:1849)
at android.support.v4.view.ViewPager.onInterceptTouchEvent(ViewPager.java:1978)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2033)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2401)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2091)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2306)
at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1575)
at android.app.Activity.dispatchTouchEvent(Activity.java:2470)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:60)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2254)
at android.view.View.dispatchPointerEvent(View.java:7888)
at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3977)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3861)
at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5101)
at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5080)
at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5179)
at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
at android.os.MessageQueue.nativePollOnce(Native Method)
at android.os.MessageQueue.next(MessageQueue.java:125)
at android.os.Looper.loop(Looper.java:138)
at android.app.ActivityThread.main(ActivityThread.java:5365)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
尝试将MainActivity父类更改为AppCompatActivity。