TabLayout 便捷实现标签

淩亂°似流年 2024-02-17 16:22 23阅读 0赞

核心：1tablayout和viewpager的关联

2.fragment嵌套在viewpager中

代码片段：

activity.xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/tabs_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
    
        <android.support.design.widget.TabLayout
            android:id="@+id/tabs_ex"
            android:layout_width="fill_parent"
    
            app:tabMode="scrollable"
            android:layout_height="wrap_content">
    
        </android.support.design.widget.TabLayout>
    
        <android.support.v4.view.ViewPager
            android:id="@+id/viewpager_ex"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"></android.support.v4.view.ViewPager>
    
    </LinearLayout>

fragment.xml

核心activity的代码：

package com.example.administrator.myapplication;
    
    import android.app.Activity;
    import android.os.Bundle;
    import android.support.design.widget.TabLayout;
    import android.support.v4.app.Fragment;
    import android.support.v4.app.FragmentActivity;
    import android.support.v4.view.ViewPager;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     * Created by Administrator on 2015/10/18.
     * <p/>
     * tab  viewpager配合使用
     * 1 xml中绘制布局，在oncreate()方法中实例化2个控件
     * 2 定义Fragment对象继承自v4包下的Fragment,在构造器中传入需要的参数
     * 3.在activity中声明数据源
     * 4.定义适配器继承自FragmentStatePagerAdapter(Fragment填充到viewpager中和tab无关)
     */
    public class TabsWithViewPagerActivity extends FragmentActivity {
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_tabswithviewpager);
            TabLayout tab = (TabLayout) findViewById(R.id.tabs_ex);
            List<String> titles = new ArrayList<>();
            List<Fragment> fragments = new ArrayList<>();
    
            for (int i = 0; i < 10; i++) {
                String title = "tabs" + i;
                tab.addTab(tab.newTab().setText(title));
                //作为fragment的数据源
                titles.add(title);
                Fragment frag = new MyFragment(title);
                fragments.add(frag);
            }
            /**
             * viewpager装填适配器
             */
            ViewPager vp = (ViewPager) this.findViewById(R.id.viewpager_ex);
            FragmentAdapter mAdapter = new FragmentAdapter(getSupportFragmentManager(), titles, fragments);
            vp.setAdapter(mAdapter);
            /**
             * 关联的核心方法
             */
            tab.setupWithViewPager(vp);  //vp
            tab.setTabsFromPagerAdapter(mAdapter);  //adapter
        }
    
    
    }

Fragment的代码：

package com.example.administrator.myapplication;
    
    import android.os.Bundle;
    import android.support.annotation.Nullable;
    import android.support.v4.app.Fragment;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    
    /**
     * Created by Administrator on 2015/10/18.
     */
    public class MyFragment extends Fragment {
    
        private String mtitle;
        private View view;
    
        public MyFragment(String title) {
            super();
            mtitle = title;
        }
    
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            view = inflater.inflate(R.layout.fragment_blank,container,false);
            TextView txt = (TextView) view.findViewById(R.id.txt);
            txt.setText(mtitle);
            return view;
        }
    }

适配器的代码：

package com.example.administrator.myapplication;
    
    import android.support.v4.app.Fragment;
    import android.support.v4.app.FragmentManager;
    import android.support.v4.app.FragmentStatePagerAdapter;
    
    import java.util.List;
    
    /**
     * Created by Administrator on 2015/10/18.
     * 适配器：
     * 1构造方法中传递需要的数据参数
     * 2.注意另外重写getPageTitle方法
     */
    public class FragmentAdapter extends FragmentStatePagerAdapter {
        List<String> mTitles;
        List<Fragment> mFrags;
    
        public FragmentAdapter(FragmentManager fm, List<String> titles, List<Fragment> frags) {
            super(fm);
            mTitles = titles;
            mFrags = frags;
        }
    
        @Override
        public Fragment getItem(int position) {
            return mFrags.get(position);
        }
    
        @Override
        public int getCount() {
            return mFrags.size();
        }
    
        @Override
        public CharSequence getPageTitle(int position) {
            return mTitles.get(position);
        }
    }