Tab系列 01 ViewPager+PagerAdapter(传统方式)

ViewPager :  左右切换屏幕

PagerAdapter:   ViewPager的适配器， 加载ViewPager内容显示的View

　　实现四个方法：

　　　　　isViewFromObject();

　　　　　getCount();

　　　　　instantiateItem();添加视图

　　　　　destroyItem（）销毁视图

pagerAdapter = new PagerAdapter() {
             @Override
            public boolean isViewFromObject(View arg0, Object arg1) {
                // TODO Auto-generated method stub
                return arg0 == arg1;
            }

            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return views.size();
            }
            @Override
            public Object instantiateItem(ViewGroup container, int position) {
                View view = views.get(position);
                container.addView(view);
                return view;
            }
            @Override
            public void destroyItem(ViewGroup container, int position,
                    Object object) {
                container.removeView(views.get(position));
            }
        };
        

Viewpager 设置滚动的事件监听：

　　onPageSelected（int arg0）;//滚动到了那个界面　　进行相应处理

viewPager.setAdapter(pagerAdapter);
        viewPager.setOnPageChangeListener(new OnPageChangeListener() {

            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub
                switch (arg0) {
                case 0:
                    tv_header.setText("微信");
                    break;
                case 1:
                    tv_header.setText("好友");
                    break;
                case 2:
                    tv_header.setText("联系人");
                    break;
                case 3:
                    tv_header.setText("我的");
                    break;
                default:
                    break;
                }
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub

            }
        });
        

视图的数据初始化， 加载视图：

inflater = LayoutInflater.from(this);
        views = new ArrayList<View>();
        View one = inflater.inflate(R.layout.tab01_content_layout, null);
        View two = inflater.inflate(R.layout.tab02_content_layout, null);
        View three = inflater.inflate(R.layout.tab03_content_layout, null);
        View four = inflater.inflate(R.layout.tab04_content_layout, null);
        views.add(one);
        views.add(two);
        views.add(three);
        views.add(four);

代码如下：

package com.example.tabdemo01;

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

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends Activity {
    private ViewPager viewPager;
    private PagerAdapter pagerAdapter;
    private LayoutInflater inflater;
    TextView tv_header;
    private List<View> views;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        viewPager.setAdapter(pagerAdapter);
        viewPager.setOnPageChangeListener(new OnPageChangeListener() {

            @Override
            public void onPageSelected(int arg0) {
                // TODO Auto-generated method stub
                switch (arg0) {
                case 0:
                    tv_header.setText("微信");
                    break;
                case 1:
                    tv_header.setText("好友");
                    break;
                case 2:
                    tv_header.setText("联系人");
                    break;
                case 3:
                    tv_header.setText("我的");
                    break;
                default:
                    break;
                }
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub

            }
        });

    }

    public void initView() {
        tv_header = (TextView) findViewById(R.id.tv_headr);
        viewPager = (ViewPager) findViewById(R.id.viewPager);
        inflater = LayoutInflater.from(this);
        views = new ArrayList<View>();
        View one = inflater.inflate(R.layout.tab01_content_layout, null);
        View two = inflater.inflate(R.layout.tab02_content_layout, null);
        View three = inflater.inflate(R.layout.tab03_content_layout, null);
        View four = inflater.inflate(R.layout.tab04_content_layout, null);
        views.add(one);
        views.add(two);
        views.add(three);
        views.add(four);

        pagerAdapter = new PagerAdapter() {
             @Override
            public boolean isViewFromObject(View arg0, Object arg1) {
                // TODO Auto-generated method stub
                return arg0 == arg1;
            }

            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return views.size();
            }
            @Override
            public Object instantiateItem(ViewGroup container, int position) {
                View view = views.get(position);
                container.addView(view);
                return view;
            }
            @Override
            public void destroyItem(ViewGroup container, int position,
                    Object object) {
                container.removeView(views.get(position));
            }
        };

    }
    public void onweixin(View view){
        viewPager.setCurrentItem(0);

    }
    public void onFriend(View view){
        viewPager.setCurrentItem(1);

    }
    public void onContacts(View view){
        viewPager.setCurrentItem(2);

    }
    public void onMyself(View view){
        viewPager.setCurrentItem(3);
    }

}