Android启动屏实现左右滑动切换查看功能

package com.devilwwj.featureguide;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

import com.devilwwj.featureguide.global.AppConstants;
import com.devilwwj.featureguide.utils.SpUtils;

public class SplashActivity extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 // 判断是否是第一次开启应用
 boolean isFirstOpen = SpUtils.getBoolean(this, AppConstants.FIRST_OPEN);
 // 如果是第一次启动，则先进入功能引导页
 if (!isFirstOpen) {
  Intent intent = new Intent(this, WelcomeGuideActivity.class);
  startActivity(intent);
  finish();
  return;
 }

 // 如果不是第一次启动app，则正常显示启动屏
 setContentView(R.layout.activity_splash);

 new Handler().postDelayed(new Runnable() {

  @Override
  public void run() {
  enterHomeActivity();
  }
 }, 2000);
 }

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

package com.devilwwj.featureguide;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;

import com.devilwwj.featureguide.global.AppConstants;
import com.devilwwj.featureguide.utils.SpUtils;

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

public class WelcomeGuideActivity extends Activity implements OnClickListener {

 private ViewPager vp;
 private GuideViewPagerAdapter adapter;
 private List<View> views;
 private Button startBtn;

 // 引导页图片资源
 private static final int[] pics = { R.layout.guid_view1,
  R.layout.guid_view2, R.layout.guid_view3, R.layout.guid_view4 };

 // 底部小点图片
 private ImageView[] dots;

 // 记录当前选中位置
 private int currentIndex;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_guide);

 views = new ArrayList<View>();

 // 初始化引导页视图列表
 for (int i = 0; i < pics.length; i++) {
  View view = LayoutInflater.from(this).inflate(pics[i], null);

  if (i == pics.length - 1) {
  startBtn = (Button) view.findViewById(R.id.btn_login);
  startBtn.setTag("enter");
  startBtn.setOnClickListener(this);
  }

  views.add(view);

 }

 vp = (ViewPager) findViewById(R.id.vp_guide);
 // 初始化adapter
 adapter = new GuideViewPagerAdapter(views);
 vp.setAdapter(adapter);
 vp.setOnPageChangeListener(new PageChangeListener());

 initDots();

 }

 @Override
 protected void onResume() {
 super.onResume();
 }

 @Override
 protected void onPause() {
 super.onPause();
 // 如果切换到后台，就设置下次不进入功能引导页
 SpUtils.putBoolean(WelcomeGuideActivity.this, AppConstants.FIRST_OPEN, true);
 finish();
 }

 @Override
 protected void onStop() {
 super.onStop();
 }

 @Override
 protected void onDestroy() {
 super.onDestroy();
 }

 private void initDots() {
 LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
 dots = new ImageView[pics.length];

 // 循环取得小点图片
 for (int i = 0; i < pics.length; i++) {
  // 得到一个LinearLayout下面的每一个子元素
  dots[i] = (ImageView) ll.getChildAt(i);
  dots[i].setEnabled(false);// 都设为灰色
  dots[i].setOnClickListener(this);
  dots[i].setTag(i);// 设置位置tag，方便取出与当前位置对应
 }

 currentIndex = 0;
 dots[currentIndex].setEnabled(true); // 设置为白色，即选中状态

 }

 /**
 * 设置当前view
 * 
 * @param position
 */
 private void setCurView(int position) {
 if (position < 0 || position >= pics.length) {
  return;
 }
 vp.setCurrentItem(position);
 }

 /**
 * 设置当前指示点
 * 
 * @param position
 */
 private void setCurDot(int position) {
 if (position < 0 || position > pics.length || currentIndex == position) {
  return;
 }
 dots[position].setEnabled(true);
 dots[currentIndex].setEnabled(false);
 currentIndex = position;
 }

 @Override
 public void onClick(View v) {
 if (v.getTag().equals("enter")) {
  enterMainActivity();
  return;
 }

 int position = (Integer) v.getTag();
 setCurView(position);
 setCurDot(position);
 }


 private void enterMainActivity() {
 Intent intent = new Intent(WelcomeGuideActivity.this,
  SplashActivity.class);
 startActivity(intent);
 SpUtils.putBoolean(WelcomeGuideActivity.this, AppConstants.FIRST_OPEN, true);
 finish();
 }

 private class PageChangeListener implements OnPageChangeListener {
 // 当滑动状态改变时调用
 @Override
 public void onPageScrollStateChanged(int position) {
  // arg0 ==1的时辰默示正在滑动，arg0==2的时辰默示滑动完毕了，arg0==0的时辰默示什么都没做。

 }

 // 当前页面被滑动时调用
 @Override
 public void onPageScrolled(int position, float arg1, int arg2) {
  // arg0 :当前页面，及你点击滑动的页面
  // arg1:当前页面偏移的百分比
  // arg2:当前页面偏移的像素位置

 }

 // 当新的页面被选中时调用
 @Override
 public void onPageSelected(int position) {
  // 设置底部小点选中状态
  setCurDot(position);
 }

 }
}