Question

我在我的Android应用中使用MainActivity和PagerSlidingTabStrip库的ViewPager有三个标签。

问题是如何在片段发生变化时更改MainActivity的菜单（即Tab更改）。

每个标签都有不同的菜单。我怎么能这样做？

Answer 1

您应该在ViewPager中使用的每个片段中覆盖 onCreateOptionsMenu ，并在扩充菜单资源之前使用menu.clear（）。

您可以在此link

中查看如何使用此功能

尝试＆＃34;在运行时更改菜单项＆＃34;章。

Answer 2

在我的情况下，我正在使用2个片段......你只是要添加一个

片段

...

 public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {


    final View rootView = inflater.inflate(R.layout.login, container, false);

...

它连接到布局登录

片段基本相同
... public View onCreateView（LayoutInflater inflater，ViewGroup容器，Bundle savedInstanceState）{
```
    View rootView = inflater.inflate(R.layout.register, container, false);
...
```
它连接到布局注册

然后我们有TabsPagerAdapter

public class TabsPagerAdapter extends FragmentPagerAdapter {

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

    @Override
    public Fragment getItem(int index) {

        switch (index) {
        case 0:
            // 1 fragment activity
            return new LoginFragment();
        case 1:
            // 2 fragment activity
            return new RegisterFragment();

        }

        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 2;
    }

}

你在MainActivity中所称的所有内容

    public class MainActivity extends FragmentActivity implements ViewPager.OnPageChangeListener, TabHost.OnTabChangeListener,ActionBar.TabListener {

    private ViewPager mViewPager;
    private TabsPagerAdapter mAdapter;
    private TabHost mTabHost;
    private String[] tabs = { "1.Fragment", "2.Fragment"};

    private TabHost.TabContentFactory mTabFactory = new TabHost.TabContentFactory() {
        @Override
        public View createTabContent(String tag) {
            View v = new View(MainActivity.this);
            v.setMinimumHeight(0);
            v.setMinimumWidth(0);
            return v;
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.view_bottomtabs);
        mViewPager = (ViewPager) findViewById(R.id.viewPager);
        mViewPager.setOnPageChangeListener(this);

        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());
        mViewPager.setAdapter(mAdapter);
        mTabHost = (TabHost) findViewById(android.R.id.tabhost);
        mTabHost.setup();
        mTabHost.setOnTabChangedListener(this);
        for (String tab_name : tabs){
            TabHost.TabSpec spec =mTabHost.newTabSpec(tab_name);
            spec.setIndicator(tab_name);
            spec.setContent(mTabFactory);
            mTabHost.addTab(spec);
        }

    }



    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        mTabHost.setCurrentTab(position);
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }

    @Override
    public void onTabChanged(String tabId) {
        int position = -1;
        if (tabId.contains("1.Fragment")) {
            position = 0;
        } else if (tabId.contains("2.Fragment")) {
            position = 1;
        }
        mViewPager.setCurrentItem(position);
    }

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

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

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


}

我希望这有帮助

片段更改时更改活动菜单

2 个答案: