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); } }}