本文介绍了选项卡布局的选项卡不显示任何内容的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
此代码将创建3个由片段组成的选项卡,其中包含图像和文字说明,每一个都带有说明.选项卡根本不显示任何内容,这三个选项都存在一个障碍.这是主要代码:
This code is to create 3 tabs, made from fragments, that contains an image and text explanation, each one of them, to it. There's an obstacle on which the tabs don't display anything at all, all 3 of them. Here is the main code :
public class Cookings extends AppCompatActivity {
private TabLayout tabLayout;
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_cookings);
tabLayout = (TabLayout) findViewById(R.id.tabLayout);
viewPager = (ViewPager) findViewById(R.id.viewpager-id);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.AddFragment(new FragmentRoastedMeat(), "Roasted Meat");
adapter.AddFragment(new FragmentStirFryVeggies(), "Stir-fry Vegetables");
adapter.AddFragment(new FragmentBakedFish(), "Baked Fish");
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
}
}
这是视图寻呼机适配器类的代码:
and here is the view pager adapter class' code :
public class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> fragmentList = new ArrayList<>();
private final List<String> fragmentListTitles = new ArrayList<>();
public ViewPagerAdapter(@NonNull FragmentManager fm) {
super(fm);
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
return fragmentListTitles.get(position);
}
@NonNull
@Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
@Override
public int getCount() {
return fragmentList.size();
}
public void AddFragment(Fragment fragment, String Title){
fragmentList.add(fragment);
fragmentListTitles.add(Title);
}
}
我想在这里解决两个关键问题:
There are two key things I'd like to fix here :
- ViewPagerAdapter类的主构造函数中对super(fm)函数的弃用,以及
- 主选项卡布局上的选项卡不显示我制作的任何片段.
任何帮助将不胜感激.
推荐答案
要弃用修复,您需要在 ViewPagerAdapter
中添加行为,如下所示:
For deprecation fix, You need to add behavior in your ViewPagerAdapter
like this:
import androidx.fragment.app.FragmentStatePagerAdapter;
....
public ViewPagerAdapter(@NonNull FragmentManager fm) {
super(fm, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
}
尝试使用以下代码:
布局
<android.support.design.widget.CoordinatorLayout 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.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMode="fixed"
app:tabGravity="fill"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
活动
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
viewPager = (ViewPager) findViewById(R.id.viewpager);
setupViewPager(viewPager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(viewPager);
}
private void setupViewPager(ViewPager viewPager) {
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new OneFragment(), "ONE");
adapter.addFragment(new TwoFragment(), "TWO");
adapter.addFragment(new ThreeFragment(), "THREE");
viewPager.setAdapter(adapter);
}
class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
}
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