如何从ViewPager和Tablayout中删除片段和选项卡？

Question

我已经搜索了很多有关此解决方案的信息。我尝试直接从mFragmentList和mFragmentTitleList中删除。我也尝试调用destroyItem。已经尝试了许多方法。他们都没有工作。我已经在这个问题上停留了几天。有什么答案可以帮助吗？谢谢。

public final  class OrdersViewPagerAdapter extends android.support.v4.app.FragmentPagerAdapter{
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();

public OrdersViewPagerAdapter(FragmentManager manager) {
    super(manager);
}

@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 void destroyItem(ViewGroup container, int position, Object object) {
    super.destroyItem(container, position, object);
    if (position <= getCount()) {
        FragmentManager manager = ((Fragment) object).getFragmentManager();
        FragmentTransaction trans = manager.beginTransaction();
        trans.remove((Fragment) object);
        trans.commit();
    }
}

@Override
public CharSequence getPageTitle(int position) {
    return mFragmentTitleList.get(position);
}

public void removeView(String  title, ViewGroup view, TabLayout tabLayout) {
    int index=-1;

    int count=mFragmentTitleList.size();

    for (int i=0;i<count;i++){
        String mtitle=mFragmentTitleList.get(i);
        if (mtitle.equals(title)){
            index=i;
            break;
        }
    }
    if (index!=-1) {
        mFragmentTitleList.remove(index);
        tabLayout.removeTabAt(index);
        destroyItem(view,index,mFragmentList.get(index));



        notifyDataSetChanged();
    }
}

}

Answer 1

好吧-这个人吃了我的午餐2周。我没有发现上述内容对我完全适用。如果有问题，我正在使用Android Studio 3.5.1。

接下来是我的FragmentPagerAdapter代码的全部。它包含您需要的大部分内容。无论您的每个片段包含什么，片段代码都非常简单。但是，如果需要更多信息或有任何疑问，请告诉我。

此外，如果您有任何评论或发现任何错误，请发表评论。我希望这对其他人有帮助。

import android.content.Context;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.fragment.app.FragmentTransaction;
import androidx.viewpager.widget.ViewPager;

import com.google.android.material.tabs.TabLayout;

import java.util.ArrayList;

public class ChecklistPagerAdapter extends FragmentPagerAdapter {

    private final Context mContext;
    private int currentTabPosition = -1;
    ArrayList<String> tabNames = new ArrayList<>();
    ArrayList<Fragment> fragments = new ArrayList<>();

    public ChecklistPagerAdapter(Context context, FragmentManager fm) {
        super(fm);
        mContext = context;
    }

    public void add(Fragment fragment, String title) {
        tabNames.add(title);
        fragments.add(fragment);
    }

    public int getCurrentTabPosition() {
        return currentTabPosition;
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getItemPosition(@NonNull Object object) {
        ChecklistFragment fragment = (ChecklistFragment) object;
        for (int i = 0; i < fragments.size(); i++) {
            if (fragments.get(i).equals(fragment)) {
                return i;
            }
        }
        return POSITION_NONE;
    }

    @Override
    public long getItemId(int position) {
        return fragments.get(position).hashCode();
    }

    @Override
    public void setPrimaryItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
        super.setPrimaryItem(container, position, object);
        currentTabPosition = position;
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        return tabNames.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }

    public void removeTab(TabLayout tabLayout, ViewPager viewPager, DBHelper dbHelper) {
        // Get current tab position as it changes below
        int position = currentTabPosition;

        // Get current fragment representing curTab
        ChecklistFragment fragment = (ChecklistFragment) fragments.get(position);

        // Remove Tab
        tabLayout.removeTabAt(position);

        // Remove from ArrayLists
        fragments.remove(position);
        tabNames.remove(position);

        // Remove fragment
        FragmentManager fragmentManager = fragment.getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.remove(fragment);
        fragmentTransaction.commit();

        // Refresh
        tabLayout.invalidate();
        notifyDataSetChanged();

        // Remove all records from ChecklistTab table
        dbHelper.clearChecklistTab(fragment.getOutingId(), fragment.getChecklistId());
    }
}