Java 如果要在多个活动中添加选项卡，是否需要多个Pager（viewpager）类？

我必须使项目包括3个活动。第一个和第二个活动由2个选项卡组成，而第三个活动需要3个选项卡。我需要为每个活动制作3个传呼机分类吗？或者如果一个Pager.class可以处理所有选项卡，那么我们如何对其排序？？

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提前感谢大家

您可以使用相同的类。只需确保重写的方法可以区分它所在的活动。因此，以

FragmentPagerAdapter

中的

getCount（）

为例，在第一个和第二个活动中返回两个，但在第三个活动中返回三个。布局也是如此。

是的，您可以为每个活动使用此pageradapter类。它将在活动中创建所需的大小

public class ExamplePagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

    public ExamplePagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

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

    @Override
   public CharSequence getPageTitle(int position) {
       return mFragmentTitleList.get(position);
    }

   public void addFragment(Fragment fragment) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }
}

公共类ExamplePagerAdapter扩展了FragmentPagerAdapter{
私有最终列表MFFragmentList=new ArrayList（）；
私有最终列表MFFragmentTitleList=new ArrayList（）；
公共示例页面编辑器（碎片管理器）{
高级经理；
}
@凌驾
公共片段getItem（int位置）{
返回MFFragmentList.get（位置）；
}
@凌驾
public int getCount（）{
返回MFFragmentList.size（）；
}
@凌驾
公共字符序列getPageTitle（int位置）{
返回MFFragmentTitleList.get（位置）；
}
公共void addFragment（片段片段）{
添加（片段）；
MFFragmentTitleList.add（标题）；
}
}

您可以使用相同的

PagerAdapter

类。下面是一个示例

PagerAdapter

TabsPagerAdapter.java

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;

import java.util.ArrayList;
import java.util.List;

public class TabsPagerAdapter extends FragmentPagerAdapter {

    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

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

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

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

    public void addFrag(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitleList.get(position);
    }
}

从您的

SecondActivity.java

：

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 2 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 2 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 3 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");
    mAdapter.addFrag(new FragmentThree(), "THREE");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

来自您的

ThirdActivity.java

：

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 2 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 2 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

TabLayout mTabLayout;
ViewPager mViewPager;
TabsPagerAdapte mAdapter;

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

    // Tab layout
    mTabLayout = (TabLayout) findViewById(R.id.tabs);

    // View pager
    mViewPager  = (ViewPager) findViewById(R.id.view_pager);

    // Adapter
    mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

    // 3 Tabs
    mAdapter.addFrag(new FragmentOne(), "ONE");
    mAdapter.addFrag(new FragmentTwo(), "TWO");
    mAdapter.addFrag(new FragmentThree(), "THREE");

    mViewPager.setAdapter(mAdapter);

    mTabLayout.setupWithViewPager(mViewPager);
    mTabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            mViewPager.setCurrentItem(tab.getPosition());
        }

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

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

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希望这会有所帮助~

我是Android studio的新手，因为我是大三学生！我想知道我必须在哪里添加我的片段？？怎么办？？因为你的代码几乎和我的代码一样，但我正试图找出在哪里添加片段？？在“addFragment”函数中？？寻呼机班？如果是，那么如何？？？从activity onCreate（）方法中，您可以使用adapter.addFrag（）方法>>>//2个选项卡mAdapter.addFrag（new FragmentOne（），“ONE”）；addfragment（新的FragmentTwo（），“TWO”）；请看我的回答。非常感谢。这很有帮助！很荣幸……：）