TabLayout+频道管理

在本项目的Gradle文件中注册:maven {url “https://jitpack.io”}

allprojects {

        repositories {
           jcenter()
           maven {url \"https://jitpack.io\"}

        }
    }

在本项目的Gradle文件中导入依赖:design(tabLayout).频道管理.Gson

    implementation \'com.android.support:design:27.1.1\'
    implementation \'com.github.andyoom:draggrid:v1.0.1\'
    implementation \'org.kie.modules:com-google-code-gson:6.5.0.Final\'

MainActivity布局:

<LinearLayout  ns:android=\"http://schemas.android.com/apk/res/android\"
     ns:app=\"http://schemas.android.com/apk/res-auto\"
     ns:tools=\"http://schemas.android.com/tools\"
    android:layout_width=\"match_parent\"
    android:layout_height=\"match_parent\"
    tools:context=\".MainActivity\"
    android:orientation=\"vertical\">

    <LinearLayout
        android:layout_width=\"match_parent\"
        android:layout_height=\"wrap_content\"
        android:orientation=\"horizontal\"
        >
      <android.support.design.widget.TabLayout
          android:layout_width=\"0dp\"
          android:layout_weight=\"1\"
          android:layout_height=\"wrap_content\"
          android:id=\"@+id/tabLayout\"
          app:tabSelectedTextColor=\"#ff00\"
          app:tabGravity=\"fill\">


      </android.support.design.widget.TabLayout>

        <Button
            android:layout_alignParentRight=\"true\"

            android:layout_width=\"wrap_content\"
            android:layout_height=\"wrap_content\"
            android:text=\"+\"
            android:background=\"#666\"
            android:id=\"@+id/button\"/>

    </LinearLayout>

    <android.support.v4.view.ViewPager
        android:layout_width=\"match_parent\"
        android:layout_height=\"0dp\"
        android:layout_weight=\"1\"
        android:id=\"@+id/pager\">

    </android.support.v4.view.ViewPager>

</LinearLayout>

全局定义变量:fragment集合.全局UI组件.频道(标题)集合.适配器

频道管理给我们提供了ChannelBean这个封装类,这个封装类中有两个属性
1.name(String) 频道名称
2.isSelect(boolean) 是否选中频道

    private ViewPager pager;
    private TabLayout tabLayout;
    private Button button;
    List<Fragment> fraglist=  new ArrayList<Fragment>();
    ArrayList<ChannelBean>  list = new ArrayList<ChannelBean>();
    private MyFragmentPagerAdapter myFragmentPagerAdapter;

MainActivity–onCreate方法:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //加载组件
        pager = findViewById(R.id.pager);
        tabLayout = findViewById(R.id.tabLayout);
        button = findViewById(R.id.button);
        //tablayout绑定pager
        tabLayout.setupWithViewPager(pager);
        //适配器
        myFragmentPagerAdapter = new MyFragmentPagerAdapter(getSupportFragmentManager());
        pager.setAdapter(myFragmentPagerAdapter);
        //创建标题and fragment集合
        initData();
        //点击+监听
        getClickListener();
    }

适配器:

class MyFragmentPagerAdapter extends FragmentPagerAdapter{

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

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

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

        @Nullable
        @Override
        //返回频道给tab
        public CharSequence getPage (int position) {
            return  list.get(position).getName();
        }
    }

初始化数据initData():

private void initData() {
        //创建频道(标题)
         list.add(new ChannelBean(\"热点\",true));
         list.add(new ChannelBean(\"军事\",true));
         list.add(new ChannelBean(\"八卦\",true));
         list.add(new ChannelBean(\"游戏\",true));
         list.add(new ChannelBean(\"宠物\",false));
         list.add(new ChannelBean(\"汽车\",false));
         list.add(new ChannelBean(\"热卖\",false));
         list.add(new ChannelBean(\"外卖\",false));
        //将选择的标签添加到tagLayout
        for (int i = 0; i < list.size() ; i++) {
            //判断此频道是否被选中
            if( list.get(i).isSelect()){
                //新建tab 将集合中的名称赋值给tab
                tabLayout.addTab(tabLayout.newTab().setText( list.get(i).getName()));
                //创建fragment, Fragment是我自己创建,继承了Fragment
                fraglist.add(new  Fragment());
            }
        }
        //刷新适配器
        myFragmentPagerAdapter.notifyDataSetChanged();
    }

getClickListener()方法:

频道管理还给我们提供了ChannelActivity(频道管理的Activity)

private void getClickListener() {

        button.set Listener(new View. Listener() {
            @Override
            public void  (View view) {
                //启动管理,跳转(进入频道管理),将频道集合传过去
                ChannelActivity.startChannelActivity(MainActivity.this, list);
            }
        });

重写onActivityResult方法接收回传值

最后进入频道管理操作频道,返回MainActivity接收回传值(选择的新频道)

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        //判断是否是频道管理的回传值
        if(requestCode==ChannelActivity.REQUEST_CODE&&resultCode==ChannelActivity.RESULT_CODE){
            //得到回传值,键为RESULT_JSON_KEY
            String stringExtra = data.getStringExtra(ChannelActivity.RESULT_JSON_KEY);
            //先清空之前tablayout上的频道
            tabLayout.removeAllTabs();
            //清空fragment
            fraglist.clear();
            //解析
            Gson gson = new Gson();
            //得到List<ChannelActivity>类型type
            Type type = new TypeToken<ArrayList<ChannelBean>>() {}.getType();
            //解析成List<ChannelActivity>类型
             list = gson.fromJson(stringExtra,type);

            //循环遍历,添加到taglayout(新频道),和fragment
            for (int i = 0; i < list.size(); i++) {
                //判断是否是选中的频道
                if( list.get(i).isSelect()){
                    tabLayout.addTab(tabLayout.newTab().setText( list.get(i).getName()));
                    fraglist.add(new  Fragment());
                }
            }
            //刷新适配器
            myFragmentPagerAdapter.notifyDataSetChanged();
        }
    }

效果图: