android中viewPager+fragment实现的屏幕左右切换(进阶篇)

Fragment支持在不同的Activity中使用并且可以处理自己的输入事件以及生命周期方法等。可以看做是一个子Activity。

先看一下布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ViewPagerActivity" >

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center" >
    </android.support.v4.view.ViewPager>

</LinearLayout>

主文件：ViewPagerActivity继承FragmentActivity

package com.example.viewpagerdemo;

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

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;

import com.example.adapter.fragmentAdapter;

public class ViewPagerActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_view_pager);
        List<Fragment> fragments = new ArrayList<Fragment>();
        for (int i = 0; i < 3; i++) {
            Fragment f = new ButtonFragment();
            fragments.add(f);
        }
        ViewPager vp = (ViewPager) findViewById(R.id.viewpager);
        fragmentAdapter fa = new fragmentAdapter(getSupportFragmentManager(),
                fragments);
        vp.setAdapter(fa);
        vp.setCurrentItem(0);
    }
}

新建fragmentAdapter继承FragmentPagerAdapter并未写出实现的方法

package com.example.adapter;

import java.util.List;

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

public class fragmentAdapter extends FragmentPagerAdapter {
    private List<Fragment> fragments;
    private FragmentManager fm;

    public fragmentAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;

    }

    public fragmentAdapter(FragmentManager fm) {
        super(fm);
        this.fm = fm;
    }

    @Override
    public Fragment getItem(int arg0) {
        return fragments.get(arg0);
    }

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

}

定义要展示的fragment内容，在这只放一个Button

package com.example.viewpagerdemo;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class ButtonFragment extends Fragment {11     private View rootView;
12
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        rootView = inflater.inflate(R.layout.guide1, container, false);
        return rootView;
18     }
19 }

至此实现3个含有Button可以左右切换了