Question

我已经创建了一个带有选项菜单的活动，我试图根据视图分页器菜单中的片段更改来设置视觉效果，这是指示空指针异常

活动

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

在我正在使用的片段中：

@SuppressLint("NewApi")
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    // TODO Auto-generated method stub
    super.onCreateOptionsMenu(menu, inflater);
    menu.findItem(R.id.refreshmenu_home_container).setVisible(false);
    menu.findItem(R.id.new_msg_chat_home_container).setVisible(true);
    menu.findItem(R.id.action_search_chat_home_container).setVisible(true);
    menu.findItem(R.id.chat_menu_attach_home_container).setVisible(true);
}

堆栈跟踪：

 03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340): java.lang.NullPointerException
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at com.rancore.messaging.ui.RTuserListFragment.onCreateOptionsMenu(RTuserListFragment.java:273)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.Fragment.performCreateOptionsMenu(Fragment.java:1582)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl.dispatchCreateOptionsMenu(FragmentManager.java:1956)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.Fragment.performCreateOptionsMenu(Fragment.java:1585)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl.dispatchCreateOptionsMenu(FragmentManager.java:1956)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:225)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v7.app.ActionBarActivity.superOnCreatePanelMenu(ActionBarActivity.java:232)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v7.app.ActionBarActivityDelegateICS.onCreatePanelMenu(ActionBarActivityDelegateICS.java:147)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v7.app.ActionBarActivity.onCreatePanelMenu(ActionBarActivity.java:199)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v7.app.ActionBarActivityDelegateICS$WindowCallbackWrapper.onCreatePanelMenu(ActionBarActivityDelegateICS.java:285)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:408)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at com.android.internal.policy.impl.PhoneWindow.invalidatePanelMenu(PhoneWindow.java:759)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.app.Activity.invalidateOptionsMenu(Activity.java:2552)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.ActivityCompatHoneycomb.invalidateOptionsMenu(ActivityCompatHoneycomb.java:29)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentActivity.supportInvalidateOptionsMenu(FragmentActivity.java:648)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v7.app.ActionBarActivity.supportInvalidateOptionsMenu(ActionBarActivity.java:170)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1116)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.BackStackRecord.popFromBackStack(BackStackRecord.java:764)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl.popBackStackState(FragmentManager.java:1562)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl$3.run(FragmentManager.java:495)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:440)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.os.Handler.handleCallback(Handler.java:605)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.os.Handler.dispatchMessage(Handler.java:92)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.os.Looper.loop(Looper.java:137)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at android.app.ActivityThread.main(ActivityThread.java:4507)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at java.lang.reflect.Method.invokeNative(Native Method)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at java.lang.reflect.Method.invoke(Method.java:511)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
    03-14 16:20:35.503 E/com.rancore.contactbook.RTContactBookActivity<======( 1340):   at dalvik.system.NativeStart.main(Native Method)

Answer 1

这是因为您错过了扩充布局文件。所以改变

   inflater.inflate(R.menu.message_user_list_menu, menu);

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // TODO Auto-generated method stub
        inflater.inflate(R.menu.message_user_list_menu, menu);
        super.onCreateOptionsMenu(menu, inflater);

            menu.findItem(R.id.refreshmenu_home_container).setVisible(false);
            menu.findItem(R.id.new_msg_chat_home_container).setVisible(true);
            menu.findItem(R.id.action_search_chat_home_container).setVisible(true);
            menu.findItem(R.id.chat_menu_attach_home_container).setVisible(true);



    }

选项菜单菜单项在android中为null

1 个答案: