java 查看寻呼机设计模式与片段。

Posted 2021-05-08

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.techpalle.karan.personaldictionary.MainActivity">

    <android.support.v7.widget.Toolbar
        style="@style/Toolbar"
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"/>

    <android.support.design.widget.TabLayout
        style="@style/Toolbar"
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>


</LinearLayout>

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:24.0.0'
    compile 'com.android.support:design:24.0.0'
    compile 'com.android.support:support-v4:24.0.0'
}

public class MainActivity extends AppCompatActivity {


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

        initializeScreen();
    }

    private void initializeScreen() {
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
        ViewPager pager = (ViewPager) findViewById(R.id.pager);

        setSupportActionBar(toolbar);

        SectionPagerAdapter adapter = new SectionPagerAdapter(getSupportFragmentManager());
        pager.setOffscreenPageLimit(3);
        pager.setAdapter(adapter);
        tabLayout.setupWithViewPager(pager);
    }

    private class SectionPagerAdapter extends FragmentStatePagerAdapter{
        public SectionPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            switch (position){
                case 0: return new FirstFragment();
                case 1: return new SecondFragment();
                case 2: return new ThirdFragment();
                default: return new FirstFragment();
            }
        }

        @Override
        public CharSequence getPageTitle(int position) {
            switch (position){
                case 0: return "First";
                case 1: return "Second";
                case 2: return "Third";
                default: return "First";
            }
        }

        @Override
        public int getCount() {
            return 3;
        }


    }
}