ViewPager手指滑动转换界面

1.首先把ViewPager里的library包导入项目中，生成库文件。

2.在layout里加入ViewPager

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

3.在代码中写出逻辑

package com.example.kaoshi;


import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.app.Activity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Menu;
import android.widget.Button;


public class MainActivity extends FragmentActivity implements OnPageChangeListener {


    private Fragment1 fragment1;
private Fragment2 fragment2;
private Fragment4 fragment4;
private ViewPager vp;
private List<Fragment>list=new ArrayList<Fragment>();
private Fragment3 f1;
private FragmentManager fragment;
private int arg;
private boolean b1=false;
private boolean b2=true;
private int index=0;


@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.aaa);
        iniView();
        iniList();
    }
private void iniList() {
list.add(new Fragment2());
list.add(new Fragment1());
list.add(new Fragment4());
f1=new Fragment3(getSupportFragmentManager());
f1.setList(list);

//创建适配器
vp.setAdapter(f1);
}

private void iniView() {
fragment1 = new Fragment1();
fragment2 = new Fragment2();
fragment4 = new Fragment4();
vp=(ViewPager) findViewById(R.id.vp);

//改变接受者
vp.setOnPageChangeListener(this);

//得到支持Fragment的控件
fragment = getSupportFragmentManager();

//创建事务
FragmentTransaction ft=fragment.beginTransaction();
fragment1 = new Fragment1();
ft.add(R.id.vp, fragment1);
ft.commit();
}
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
if(arg0==ViewPager.SCROLL_STATE_IDLE){
b1 = false;
}else {
b1=true;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub

}
@Override
public void onPageSelected(int arg0) {
FragmentTransaction f1 = fragment.beginTransaction();
switch (arg0) {
case 0:
qinglingfr();
f1.show(fragment1);
f1.commit();
break;
case 1:
qinglingfr();
if(fragment2==null){
fragment2=new Fragment2();
f1.add(R.id.vp, fragment2);
}else {
f1.show(fragment2);
}
f1.commit();
break;
case 2:
qinglingfr();
if(fragment4==null){
fragment4=new Fragment4();
f1.add(R.id.vp, fragment4);
}else {
f1.show(fragment4);
}
f1.commit();
break;
default:
break;
}
}

//清零  
private void qinglingfr(){
android.support.v4.app.FragmentTransaction ft=fragment.beginTransaction();
if(fragment1!=null){
ft.hide(fragment1);
}
if(fragment2!=null){
ft.hide(fragment2);
}
if(fragment4!=null){
ft.hide(fragment4);
}
ft.commit();
} 


}

//Fragment3 的类

public class Fragment3 extends FragmentPagerAdapter {
private List<Fragment>list;
public Fragment3(FragmentManager fm) {
super(fm);
}
public void setList(List<Fragment>list){
this.list=list;
}
@Override
public Fragment getItem(int arg0) {
return list.get(arg0);
}


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


}