在 fragmentpageradapter 中重用片段 [英] reusing fragments in a fragmentpageradapter

问题描述

我有一个 viewpager 可以浏览片段.我的 FragmentPagerAdapter 子类在 getItem 方法中创建了一个看起来很浪费的新片段.是否有与 listAdapter 中的 convertView 等效的 FragmentPagerAdapter 使我能够重用已创建的片段?我的代码如下.

I have a viewpager that pages through fragments. My FragmentPagerAdapter subclass creates a new fragment in the getItem method which seems wasteful. Is there a FragmentPagerAdapter equivalent to the convertView in the listAdapter that will enable me to reuse fragments that have already been created? My code is below.

public class ProfilePagerAdapter extends FragmentPagerAdapter {

    ArrayList<Profile> mProfiles = new ArrayList<Profile>();

    public ProfilePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    /**
     * Adding a new profile object created a new page in the pager this adapter is set to.
     * @param profile
     */
    public void addProfile(Profile profile){
        mProfiles.add(profile);
    }

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

    @Override
    public Fragment getItem(int position) {
        return new ProfileFragment(mProfiles.get(position));
    }
}

推荐答案

FragmentPagerAdapter 已经为你缓存了 Fragments.每个片段都分配了一个标签，然后 FragmentPagerAdapter 尝试调用 findFragmentByTag.如果 findFragmentByTag 的结果为 null，它只会调用 getItem.所以你不应该自己缓存这些片段.

The FragmentPagerAdapter already caches the Fragments for you. Each fragment is assigned a tag, and then the FragmentPagerAdapter tries to call findFragmentByTag. It only calls getItem if the result from findFragmentByTag is null. So you shouldn't have to cache the fragments yourself.

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