我目前有这个标签视图，我从this教程开始。一切正常，直到我注意到任何标签上都没有调用CONSTRAINT FOREIGN KEY fk_address_owner
ADDRESS.owner_id
REFERENCES (which table?) (id)
。我在这里和那里寻找解决方案，但我仍然无法解决。
这是我的代码：
onCreateView
activity_pref_main_container.xml <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:id="@+id/main_layout"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".PrefActivityMain">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:background="?attr/colorPrimary"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/toolbar"
android:background="?attr/colorPrimary"
android:elevation="6dp"
android:minHeight="?attr/actionBarSize"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_below="@id/tab_layout"/>
</RelativeLayout>
PrefMainActivity.class @Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pref_main_container);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle(R.string.preference_title);
setSupportActionBar(toolbar);
new PrefActivityListAsync(this,this,specialization).execute();
new PrefActivityListAsync(this,this,position).execute();
new PrefActivityListAsync(this,this,type).execute();
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Specialization"));
tabLayout.addTab(tabLayout.newTab().setText("Position"));
tabLayout.addTab(tabLayout.newTab().setText("Type"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PrefAdapter adapter = new PrefAdapter(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
viewPager.setOffscreenPageLimit(2);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
PrefAdapder.class三分之一的片段类
public class PrefAdapter extends FragmentPagerAdapter {
int mNumOfTabs;
public PrefAdapter(FragmentManager fm, int NumOfTabs) {
super(fm);
this.mNumOfTabs = NumOfTabs;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
PrefActivitySpecialization tab1 = new PrefActivitySpecialization();
return tab1;
case 1:
PrefActivityPosition tab2 = new PrefActivityPosition();
return tab2;
case 2:
PrefActivityType tab3 = new PrefActivityType();
return tab3;
default:
return null;
}
}
@Override
public int getCount() {
return 0;
}
}
PrefActivitySpecialization.class答案 0 :(得分：6)
您应该在两个地方进行更改：
1）改变
--collapse到
@Override
public int getCount() {
return 0;
}
2）改变
@Override
public int getCount() {
return mNumOfTabs;
}
到
return inflater.inflate(R.layout.activity_pref_specialization_container, container, false);
答案 1 :(得分：2)
public PrefAdapter（FragmentManager fm，int NumOfTabs）
您必须声明Count No NumOfTabs
int getCount（） - ＆gt;由此表示的数据集中有多少项 适配器。
@Override
public int getCount()
{
return mNumOfTabs;
}
不要 '
return inflater.inflate(R.layout.activity_pref_specialization_container, container, false);
<强> 待办事项
return view ;
答案 2 :(得分：1)
您的getCount()方法返回0;
答案 3 :(得分：0)
还有另一种（可能更简单的方法）将视图寻呼机与标签布局连接起来 -
首先，在您的PrefAdapter课程中，覆盖getPageTitle()方法，然后从那里返回相应标签位置的标题标题。
在PrefMainActivity课程中，删除以下所有行：
tabLayout.addTab(...)
添加以下行代替 -
tabLayout.setupWithViewPager(viewPager);