我不想在更改时刷新片段

Question

我有3个片段......带有3个导航标签.

问题是,如果我在第一个选项卡上,我点击第三个..当我再次点击第一个时,它会重新加载所有片段.如果我单击第二个选项卡(在中间)并单击第一个选项卡,则不会重新加载.

我的目标是我不想永远刷新我的碎片!

我该怎么做？

我的代码是:

public class TabsPagerAdapter extends FragmentPagerAdapter {

    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
    }
// Return Items
    @Override
    public Fragment getItem(int index) {

        switch (index) {
        case 0:
            return new Retos();
        case 1:
            return new Amics();
        case 2:
            return new Ranking();
        }

        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 3;
    }

}

还有这个 :

public class Perfil extends ActionBarActivity implements ActionBar.TabListener{

private ViewPager viewPager;
private TabsPagerAdapter mAdapter;
private ActionBar actionBar;
private SearchView mSearchView;
private TextView mStatusView;
// Tab titles
private String[] tabs = { "TAB1", "TAB2", "TAB3" };



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


    // Initilization
    viewPager = (ViewPager) findViewById(R.id.pager);
    actionBar = getSupportActionBar();
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    viewPager.setAdapter(mAdapter);
    actionBar.setHomeButtonEnabled(true);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);    


    /** Creating fragment1 Tab */
    Tab tab = actionBar.newTab()
        .setText("TAB1")
        .setTabListener(this);

    actionBar.addTab(tab);

    /** Creating fragment2 Tab */
    tab = actionBar.newTab()
        .setText("TAB2")
        .setTabListener(this);
        //.setIcon(R.drawable.ic_action_group);

    actionBar.addTab(tab);

    /** Creating fragment3 Tab */
    tab = actionBar.newTab()
        .setText("TAB3")
        .setTabListener(this);

    actionBar.addTab(tab);




    /**
     * on swiping the viewpager make respective tab selected
     * */
    viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

        @Override
        public void onPageSelected(int position) {
            // on changing the page
            // make respected tab selected
            actionBar.setSelectedNavigationItem(position);

        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
        }

        @Override
        public void onPageScrollStateChanged(int arg0) {
        }
    });
}


@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    // on tab selected
    // show respected fragment view
    viewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
}

}

Answer 1

viewPager.setOffscreenPageLimit(C_FRAGMENTS_TO_KEEP_IN_MEMORY);

C_FRAGMENTS_TO_KEEP_IN_MEMORY是当前所选选项卡右侧和左侧的选项卡数,以保留在内存中.所以在你的情况下应该是2.

每次在viewpager适配器中调用getItem方法时,请确保不要创建新的片段实例.

检查此页面中的@Rarw答案.