fragment与viewPager的结合

ゝ一世哀愁。 2022-08-20 15:11 194阅读 0赞

通过fragment与viewPager实现如下的效果（可以手指滑动切换界面，也可以点击按钮切换界面）：  
![这里写图片描述][20160303233024944]

1、创建好项目后，再创建四个继承了Fragment的子类，OneFragment、TwoFragment、ThreeFragment、FourFragment，及其对应的layout布局文件，因代码差不多，这里只给出其中一个：  
OneFragment 的代码：

package com.lu.fragmeng;
    
    import android.support.v4.app.Fragment;
    import android.os.Bundle;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    
    public class OneFragment extends Fragment { 
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) 
        {
            return inflater.inflate(R.layout.one_fragment, null);
        }
    
    }

OneFragment 的布局文件one\_fragment：

<?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#f00" >
        <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="1" android:textSize="28sp" android:layout_gravity="center_vertical|center_horizontal" />
    
    </FrameLayout>

MainActivity继承的是FragmengActivity，代码如下：

package com.lu.fragmeng;
    
    import java.util.ArrayList;
    
    import android.support.v4.app.Fragment;
    import android.support.v4.app.FragmentManager;
    import android.os.Bundle;
    import android.support.v4.app.FragmentActivity;
    import android.support.v4.app.FragmentPagerAdapter;
    import android.support.v4.view.ViewPager;
    import android.support.v4.view.ViewPager.OnPageChangeListener;
    import android.view.View;
    import android.widget.Button;
    
    public class MainActivity extends FragmentActivity { 
        OneFragment oneFragment;
        TwoFragment twoFragment;
        ThreeFragment threeFragment;
        FourFragment fourFragment;
    
        Button btn1, btn2, btn3, btn4;
        ViewPager viewPager;
        ArrayList<Fragment> fragmentList;       //集合用于存放四个Fragment对象；
        OnPageChangeListener pageChangeListener;//viewPager的事件监听；
    
        @Override
        protected void onCreate(Bundle savedInstanceState) 
        {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            loadUI();
            viewPager.setAdapter(new MyAdapter(getSupportFragmentManager()));
            viewPager.setCurrentItem(0);
            changeItem();
            viewPager.setOnPageChangeListener(pageChangeListener);//viewPager的事件监听；
        }
    
        private void loadUI()
        {
            btn1 = (Button)findViewById(R.id.btn1);
            btn2 = (Button)findViewById(R.id.btn2);
            btn3 = (Button)findViewById(R.id.btn3);
            btn4 = (Button)findViewById(R.id.btn4);
            viewPager = (ViewPager)findViewById(R.id.viewPager);
    
            fragmentList = new ArrayList<Fragment>();
            oneFragment = new OneFragment();
            twoFragment = new TwoFragment();
            threeFragment = new ThreeFragment();
            fourFragment = new FourFragment();
    
            fragmentList.add(oneFragment);
            fragmentList.add(twoFragment);
            fragmentList.add(threeFragment);
            fragmentList.add(fourFragment);
        }
    
        //viewPager的事件监听；
        private void changeItem()
        {
            pageChangeListener = new OnPageChangeListener() 
            {           
                @Override
                public void onPageSelected(int position) 
                {
                    viewPager.setCurrentItem(position);
                }
    
                @Override
                public void onPageScrolled(int arg0, float arg1, int arg2) 
                {               
                }
    
                @Override
                public void onPageScrollStateChanged(int arg0) 
                {               
                }
            };
        }
    
        public void changeView(View view)
        {
            switch(view.getId())
            {
            case R.id.btn1:
                viewPager.setCurrentItem(0);
                break;
            case R.id.btn2:
                viewPager.setCurrentItem(1);
                break;
            case R.id.btn3:
                viewPager.setCurrentItem(2);
                break;
            case R.id.btn4:
                viewPager.setCurrentItem(3);
                break;
            }
        }
    
        class MyAdapter extends FragmentPagerAdapter
        {
    
            public MyAdapter(FragmentManager fm) 
            {
                super(fm);
            }
    
            @Override
            public Fragment getItem(int position) 
            {
                return fragmentList.get(position);
            }
    
            @Override
            public int getCount() 
            {
                return fragmentList.size();
            }       
        }
    }

布局代码：

[20160303233024944]: /images/20220731/c8a4e9acd590460bacce509d2e89a972.png