引导页ViewPager当滑动到最后一页,再继续滑动切换页面的效果实现

/**
*
* 引导页界面(viewpager)
* */
public class IntroActivity extends Activity implements View.OnClickListener{

//TODO 图片资源(测试用小绿机器人,正式后要替换)
int[] image={R.mipmap.ic_launcher,R.mipmap.ic_launcher,R.mipmap.ic_launcher};

List<View> images=new ArrayList<>();
private ViewPager vp;
private Button bt;

private int currentPage;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//      根据版本号判断是不是第一次使用
PackageInfo info=null;
try {
info=getPackageManager().getPackageInfo(getPackageName(),0);

} catch (PackageManager.NameNotFoundException e) {
e.printStackTrace();
}
final int currentVersion = info.versionCode;
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);

Float lastVersion = sp.getFloat("VERSION_KEY", 0);

if (currentVersion>lastVersion){
//            第一次启动将当前版本进行存储
sp.edit().putFloat("VERSION_KEY",currentVersion).commit();
setContentView(R.layout.activity_intro);
//将图片添加到list<view>集合中
for (int i = 0; i < image.length; i++) {
ImageView iv=new ImageView(this);
iv.setImageResource(image[i]);
iv.setScaleType(ImageView.ScaleType.FIT_XY);
images.add(iv);

}

vp = (ViewPager) findViewById(R.id.vp);
bt = (Button) findViewById(R.id.gointo_app_bt);

GuildPagerAdapter adapter=new GuildPagerAdapter(images);
vp.setAdapter(adapter);

vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

}

@Override
public void onPageSelected(int position) {
//currentpage后面要用
currentPage=position;
if(position==2){
//设置可见,如果用按钮也可以实现activity的跳转,两种跳转功能都具备
bt.setVisibility(View.VISIBLE);
bt.setOnClickListener(IntroActivity.this);
}else {
bt.setVisibility(View.GONE);
}
}

@Override
public void onPageScrollStateChanged(int state) {

}
});
//设置ViewPager的滑动监听,为了滑动到最后一页,继续滑动实现页面的跳转
vp.setOnTouchListener(new View.OnTouchListener() {
float startX;

float endX;

@Override
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startX = event.getX();

break;
case MotionEvent.ACTION_UP:
endX = event.getX();
//获取屏幕的宽度
int width = ScreenUtils.getScreenWidth(getApplicationContext());
//根据滑动的距离来切换界面
if (currentPage == 2 && startX - endX >= (width / 5)) {

startApp();//切换界面
}

break;
}
return false;
}
});

}else {
//            非第一次启动直接跳转
startApp();
}

}

private void startApp() {
Intent intent=new Intent(this,SplashActivity.class);
startActivity(intent);
finish();
}

//button 点击事件
public void onClick(View view) {
startApp();

}

/**
*@author Administrator
*@date 2016/12/2 0002  上午 9:26
*@Description viewpager 的适配器,内容不多直接写内部类了
*@param
*@retrun
*/
public class GuildPagerAdapter extends PagerAdapter{
List<View> list;

public GuildPagerAdapter(List<View> list) {
this.list = list;
}

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

@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(list.get(position));
return list.get(position);
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView(list.get(position));

}

@Override
public boolean isViewFromObject(View view, Object object) {
return view==object;
}
}

}

<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/vp"></android.support.v4.view.ViewPager>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/gointo_app_bt"
android:background="@drawable/gointo_app_bg"
android:text="点击进入App"
android:textSize="28sp"
android:onClick="onClick"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:visibility="gone"/>