Android技巧一之启动屏+新功能左右导航逻辑

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;/*** @desc 启动屏* Created by devilwwj on 16/1/23.*/public class SplashActivity extends Activity {@Overrideprotected 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() {@Overridepublic void run() {enterHomeActivity();}}, 2000);}private void enterHomeActivity() {Intent intent = new Intent(this, MainActivity.class);startActivity(intent);finish();}}代码解析：使用SharedPreference来保存app启动状态，如果为true，则进入功能导航，否则延迟2秒之后进入主页面。WelcomeGuideActivity.javapackage 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;/*** 欢迎页* * @author wwj_748* */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;@Overrideprotected 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adapteradapter = new GuideViewPagerAdapter(views);vp.setAdapter(adapter);vp.setOnPageChangeListener(new PageChangeListener());initDots();}@Overrideprotected void onResume() {super.onResume();}@Overrideprotected 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();}@Overrideprotected void onStop() {super.onStop();}@Overrideprotected 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;}@Overridepublic 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@Overridepublic 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@Overridepublic 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@Overridepublic void onPageSelected(int position) {// 设置底部小点选中状态setCurDot(position);}}}