Android |停止TabLayout重新加载/刷新我的片段 [英] Android | stop TabLayout reload/refresh my Fragments

问题描述

我的标签布局类似，有4个标签.

I've a similar tab layout, with 4 tabs.

当我从标签0 转到标签2 ，然后又回到标签0 时，Fragment0被重新加载.我从一个标签转到另一个离开"标签.
我只会在第一次加载Fragment并重新使用它们，而无需重新加载.

When I go from tab 0 to tab 2 and then I come back to tab 0, Fragment0 is reloaded.. Same problem when I go from a tab to another "away" tab.
I would to load Fragment only first time and re-use them, without reloading.

这是我的代码的一部分(我正在使用

This is a part of my code (I've using this tutorial):

MyActivity:

MyActivity:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.my_activity);

    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    if(getSupportActionBar()!=null) {
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    }

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        Window window = MyActivity.this.getWindow();
        window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
        window.clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
        window.setStatusBarColor(ContextCompat.getColor(MyActivity.this, R.color.colorPrimaryDark));
    }

    viewPager = (ViewPager) findViewById(R.id.viewpager);
    setupViewPager(viewPager);

    tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setSelectedTabIndicatorColor(Color.parseColor("#FFFFFF"));
    tabLayout.setupWithViewPager(viewPager);
    setupTabIcons(); //I have only icon, not text.
}

private void setupViewPager(ViewPager viewPager) {
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(MyFragment.newInstance(0));
    adapter.addFragment(MyFragment.newInstance(1));
    adapter.addFragment(new DifferentFragment());
    adapter.addFragment(new TestFragment());
    viewPager.setAdapter(adapter);
}

class ViewPagerAdapter extends FragmentPagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();

    public ViewPagerAdapter(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) {
        mFragmentList.add(fragment);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return null;
    }
}

my_activity.xml:

my_activity.xml:

<?xml version="1.0" encoding="utf-8"?>
<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>

推荐答案

我自己解决了简单，使用:

I solved it by myself Simple, use:

viewPager.setOffscreenPageLimit(numberOfPages);

从参考开始:设置处于空闲状态的视图层次结构中应保留到当前页面任一侧的页面数.

From reference: Set the number of pages that should be retained to either side of the current page in the view hierarchy in an idle state.

就我而言，我需要保留 3 个页面.

In my case, I need 3 pages that should be retained.

这篇关于Android |停止TabLayout重新加载/刷新我的片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！