Question

我想知道是否有人可以帮助我。我需要在运行时更改单个选项卡中的片段。我知道它应该使用FragmentPagerAdapter来完成，但是我已经设法找到了它。我正在使用android studio。我的项目在API 22上运行。感谢所有答案！编辑：这是代码。

这里我设置了选项卡式布局类

Stack<Fragment> Tab1;
Stack<Fragment> Tab2;
Stack<Fragment> Tab3;

private SectionsPagerAdapter mSectionsPagerAdapter;

private ViewPager mViewPager;

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

    /*Tab1 = new Stack<Fragment>();
    Tab1.addElement(new Tab1Informations());
    Tab2 = new Stack<Fragment>();
    Tab2.addElement(new Tab2Events());
    Tab3 = new Stack<Fragment>();
    Tab3.addElement(new tab3tests());*/

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    //mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager(), Tab1.peek(), Tab2.peek(), Tab3.peek());
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager(),new Tab1Informations(), new Tab2Events(), new tab3tests());
    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);

    mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));

    CreateButtonListener();
}

这里我尝试更改SectionChangedAdapter

Stack<Fragment> Tab1;
Stack<Fragment> Tab2;
Stack<Fragment> Tab3;

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link FragmentPagerAdapter} derivative, which will keep every
 * loaded fragment in memory. If this becomes too memory intensive, it
 * may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
private SectionsPagerAdapter mSectionsPagerAdapter;

private ViewPager mViewPager;

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

    /*Tab1 = new Stack<Fragment>();
    Tab1.addElement(new Tab1Informations());
    Tab2 = new Stack<Fragment>();
    Tab2.addElement(new Tab2Events());
    Tab3 = new Stack<Fragment>();
    Tab3.addElement(new tab3tests());*/
    //mSectionsPagerAdapter = new 
     SectionsPagerAdapter(getSupportFragmentManager(), Tab1.peek(), 
     Tab2.peek(), Tab3.peek());
    mSectionsPagerAdapter = new 
   SectionsPagerAdapter(getSupportFragmentManager(),new Tab1Informations(), 
    new Tab2Events(), new tab3tests());
    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);

    mViewPager.addOnPageChangeListener(new 
    TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.addOnTabSelectedListener(new 
    TabLayout.ViewPagerOnTabSelectedListener(mViewPager));

    CreateButtonListener();
}

在这里我定义了适配器本身。公共类SectionsPagerAdapter扩展 FragmentPagerAdapter { 片段tab1; 片段tab2; 片段tab3;

    public SectionsPagerAdapter(FragmentManager fm, Fragment tab1, Fragment 
    tab2, Fragment tab3){
        super(fm);
        this.tab1 = tab1;
        this.tab2 = tab2;
        this.tab3 = tab3;
    }

    @Override
    public Fragment getItem(int position){
        switch(position){
            case 0:
                return tab1;
            case 1:
                return tab2;
            case 2:
                return tab3;
            default:
                return null;
        }
    }

    @Override
    public int getCount(){
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position){
        switch(position){
            case 0:
                return getString(R.string.InformationsTabTitle);
            case 1:
                return getString(R.string.EventsTabTitle);
            case 2:
                return getString(R.string.TestsTabTitle);
            default:
                return null;
        }
    }
}`

Answer 1

如果不使用视图寻呼机

    //..............

tabLayoutMain = (TabLayout) findViewById(R.id.tabLayoutMain);
tabLayoutMain.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
  @Override
  public void onTabSelected(TabLayout.Tab tab) {
    selectTab(tab);
  }

  private void selectTab(TabLayout.Tab tab) {
    // do something
    tabText = "" + tab.getText();
    handelTabsSelection(tabText);
  }

  @Override
  public void onTabReselected(TabLayout.Tab tab) {
    if (tab.getPosition() == 0) {
      selectTab(tab);

      tabLayoutMain.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {

        @Override
        public void onTabSelected(TabLayout.Tab tab) {
          selectTab(tab);
        }

        @Override
        public void onTabReselected(TabLayout.Tab arg0) {
        }

        @Override
        public void onTabUnselected(TabLayout.Tab arg0) {
        }
      });

    }
  }


  @Override
  public void onTabUnselected(TabLayout.Tab tab) {
  }

});

和

private void handelTabsSelection(String tabText) {
switch (tabText) {
  case "news":
        FragmentTransaction fragmentTransaction =getFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.placeholder, new NewsFragment());
        fragmentTransaction.commit();

    break;
  default:
        FragmentTransaction fragmentTransaction =getFragmentManager().beginTransaction();
        fragmentTransaction.replace(R.id.placeholder, new HomeFragment());
        fragmentTransaction.commit();



}

}

在运行时期间更改tablayout中选项卡中的片段

1 个答案: