这篇文章给大家介绍怎么在Android应用中添加一个欢迎界面，内容非常详细，感兴趣的小伙伴们可以参考借鉴，希望对大家能有所帮助。
main_activity.xml文件代码如下：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@color/white" android:orientation="vertical" ><com.qianmo.xiaohongshuwelcome.parallaxpager.ParallaxContainer android:id="@+id/parallax_container" android:layout_width="match_parent" android:layout_height="match_parent"/> <ImageView android:id="@+id/iv_man" android:layout_width="67dp" android:layout_height="202dp" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="10dp"android:background="@drawable/intro_item_manrun_1" android:visibility="visible" /></RelativeLayout>可以看到我们主界面的布局文件主要是两个控件，一个是包含上面小人行走效果的ImageView，然后是一个自定义ParallaxContainer控件，这个自定义控件的具体是什么我们先不要管，后面再和大家来慢慢解释
第二步：看一下我们主界面的MainActivity的代码
MainActivity.java
package com.qianmo.xiaohongshuwelcome;import android.app.Activity;import android.content.ActivityNotFoundException;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.view.View;import android.view.Window;import android.view.WindowManager;import android.widget.ImageView;import com.qianmo.xiaohongshuwelcome.parallaxpager.ParallaxContainer;public class MainActivity extends Activity { ImageView iv_man; ImageView rl_weibo; ParallaxContainer parallaxContainer; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //获取当前窗体 final Window window = getWindow(); window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); setContentView(R.layout.activity_main); if (android.os.Build.VERSION.SDK_INT > 10) { iv_man = (ImageView) findViewById(R.id.iv_man); parallaxContainer = (ParallaxContainer) findViewById(R.id.parallax_container); if (parallaxContainer != null) { parallaxContainer.setImage(iv_man); parallaxContainer.setLooping(false); iv_man.setVisibility(View.VISIBLE); parallaxContainer.setupChildren(getLayoutInflater(), R.layout.view_intro_1, R.layout.view_intro_2, R.layout.view_intro_3, R.layout.view_intro_4, R.layout.view_intro_5, R.layout.view_intro_6 ,R.layout.view_login); } } else{ setContentView(R.layout.view_login); } }}我们看到代码很简单，主要是这几句有用的代码：
if (parallaxContainer != null) { parallaxContainer.setImage(iv_man); parallaxContainer.setLooping(false); iv_man.setVisibility(View.VISIBLE); parallaxContainer.setupChildren(getLayoutInflater(), R.layout.view_intro_1, R.layout.view_intro_2, R.layout.view_intro_3, R.layout.view_intro_4, R.layout.view_intro_5, R.layout.view_intro_6 ,R.layout.view_login);}① 将我们小人走路的那个ImageView添加到自定义控件ParallaxContainer中
② 将我们每一个的布局文件set到ParallaxContainer控件中去
这里给出R.layout.view_intro_1.xml文件代码，其他的类似，就不给出来了（这里的x_in、x_out、y_in等属性注意一下）
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="fill_parent" android:layout_height="fill_parent" > <ImageView android:id="@+id/iv_0" android:layout_width="103dp" android:layout_height="19dp" android:layout_centerInParent="true" android:src="@drawable/intro1_item_0" app:x_in="1.2" app:x_out="1.2" /> <ImageView android:id="@+id/iv_1" android:layout_width="181dp" android:layout_height="84dp" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" android:layout_marginLeft="13dp" android:layout_marginTop="60dp" android:src="@drawable/intro1_item_1" app:x_in="0.8" app:x_out="0.8" /> <ImageView android:id="@+id/iv_2" android:layout_width="143dp" android:layout_height="58dp" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_marginTop="109dp" android:src="@drawable/intro1_item_2" app:x_in="1.1" app:x_out="1.1" /> <ImageView android:id="@+id/iv_3" android:layout_width="48dp" android:layout_height="48dp" android:src="@drawable/intro1_item_3" app:x_in="0.8" app:x_out="0.8" app:a_in="0.8" app:a_out="0.8" android:layout_below="@+id/iv_0" android:layout_toRightOf="@+id/iv_5" android:layout_toEndOf="@+id/iv_5" android:layout_marginLeft="21dp" android:layout_marginStart="21dp" android:layout_marginTop="12dp"/> <ImageView android:id="@+id/iv_4" android:layout_width="fill_parent" android:layout_height="128dp" android:layout_alignParentBottom="true" android:layout_marginBottom="29dp" android:background="@drawable/intro1_item_4" app:a_in="0.8" app:a_out="0.8" app:x_in="0.8" app:x_out="0.8" /> <ImageView android:id="@+id/iv_5" android:layout_width="260dp" android:layout_height="18dp" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" android:layout_marginBottom="16dp" android:layout_marginLeft="15dp" android:src="@drawable/intro1_item_5" app:a_in="0.9" app:a_out="0.9" app:x_in="0.9" app:x_out="0.9" /> <ImageView android:id="@+id/iv_6" android:layout_width="24dp" android:layout_height="116dp" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" android:layout_marginBottom="35dp" android:layout_marginLeft="46dp" android:src="@drawable/intro1_item_6" app:x_in="0.6" app:x_out="0.6" /> <ImageView android:id="@+id/iv_7" android:layout_width="45dp" android:layout_height="40dp" android:layout_alignParentBottom="true" android:layout_alignParentLeft="true" android:layout_marginBottom="23dp" android:layout_marginLeft="76dp" android:src="@drawable/intro1_item_7" app:a_in="0.3" app:a_out="0.3" app:x_in="0.5" app:x_out="0.5" /></RelativeLayout>第三步：好了现在我们一定很好奇ParallaxContainer里面的内容，那我们从上面的方法慢慢去看，首先看一下ParallaxContainer中的setImage（）方法，代码如下：
ImageView iv;//将小人图片添加进来public void setImage(ImageView iv) { this.iv = iv;}貌似没有什么，只是将它赋值给成员变量iv，我们接着看下一个setUpChildren()方法
//添加子viewpublic void setupChildren(LayoutInflater inflater, int... childIds) { if (getChildCount() > 0) { throw new RuntimeException("setupChildren should only be called once when ParallaxContainer is empty"); } //创建打气筒 ParallaxLayoutInflater parallaxLayoutInflater = new ParallaxLayoutInflater( inflater, getContext()); //将所有的view添加到本控件上去 for (int childId : childIds) { View view = parallaxLayoutInflater.inflate(childId, this); viewlist.add(view); } //添加视觉view pageCount = getChildCount(); for (int i = 0; i < pageCount; i++) { View view = getChildAt(i); addParallaxView(view, i); } //更新ViewPagerAdapter的数量 updateAdapterCount(); //创建viewpager viewPager = new ViewPager(getContext()); viewPager.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); viewPager.setId(R.id.parallax_pager); //给viewpager添加滑动监听 attachOnPageChangeListener(); //设置适配器 viewPager.setAdapter(adapter); //将viewpager添加到主控件中 addView(viewPager, 0);}让我们一行行代码慢慢分析
if (getChildCount() > 0) { throw new RuntimeException("setupChildren should only be called once when ParallaxContainer is empty"); }//创建打气筒 ParallaxLayoutInflater parallaxLayoutInflater = new ParallaxLayoutInflater( inflater, getContext());首先看一下这段代码只是if判断是否已经调用过setUpChildren()方法，没什么重要的，在看创建ParallaxLayoutInflater打气筒对象，我们来看看ParallaxLayoutInflater的具体代码，没什么重要的，只是里面有一个ParallaxFactory类我们没见过，留心一下！
package com.qianmo.xiaohongshuwelcome.parallaxpager;import android.content.Context;import android.view.LayoutInflater;public class ParallaxLayoutInflater extends LayoutInflater { protected ParallaxLayoutInflater(LayoutInflater original, Context newContext) { super(original, newContext); setUpLayoutFactory(); } private void setUpLayoutFactory() { if (!(getFactory() instanceof ParallaxFactory)) { setFactory(new ParallaxFactory(this, getFactory())); } } @Override public LayoutInflater cloneInContext(Context newContext) { return new ParallaxLayoutInflater(this, newContext); }}再看下面一段代码，主要是将所有的布局文件添加到viewList集合中去，并填充到我们的布局中，我们继续往下看
//将所有的view添加到本控件上去 for (int childId : childIds) { View view = parallaxLayoutInflater.inflate(childId, this); viewlist.add(view); }下面一段代码主要是看拿到对应所有的子view，关键是我们的addParallaxView（）方法，具体代码如下：
//添加视觉view pageCount = getChildCount(); for (int i = 0; i < pageCount; i++) { View view = getChildAt(i); addParallaxView(view, i); } private void addParallaxView(View view, int pageIndex) { //通过递归方法拿到最小单元的view if (view instanceof ViewGroup) { ViewGroup viewGroup = (ViewGroup) view; for (int i = 0, childCount = viewGroup.getChildCount(); i < childCount; i++) { addParallaxView(viewGroup.getChildAt(i), pageIndex); } } //创建视觉差view绑定，并添加到集合中去 ParallaxViewTag tag = (ParallaxViewTag) view.getTag(R.id.parallax_view_tag); if (tag != null) { tag.index = pageIndex; parallaxViews.add(view); } }通过递归将每个布局文件中的最小单元view保存到parallaxView集合中去，但是等等，这里我们又发现了一个新的类ParallaxViewTag，让我们来具体代码
package com.qianmo.xiaohongshuwelcome.parallaxpager;public class ParallaxViewTag { //绑定每一个view对应的是哪一个下标的 protected int index; //x轴进入的速度 protected float xIn; protected float xOut; protected float yIn; protected float yOut; protected float alphaIn; protected float alphaOut;}貌似很简单，xIn、xOut貌似很熟悉和我们之前的布局文件属性app:x_in等属性对应了， 这样我们就懂了，这个类是相当于一个tag类，用于记录我们设置的特殊一些属性，然是我们这里有一个疑问，下面这个代码是get到tag，那我们是在哪里set里面的属性呢？
ParallaxViewTag tag = (ParallaxViewTag) view.getTag(R.id.parallax_view_tag);
这时候我们要看看我们前面提到过的一个陌生类ParallaxFactory，看一下具体代码
package com.qianmo.xiaohongshuwelcome.parallaxpager;import android.content.Context;import android.content.res.TypedArray;import android.util.AttributeSet;import android.view.LayoutInflater;import android.view.View;import com.qianmo.xiaohongshuwelcome.R;public class ParallaxFactory implements LayoutInflater.Factory { private final LayoutInflater.Factory factory; private ParallaxLayoutInflater mInflater; private static final String[] sClassPrefixList = { "android.widget.", "android.webkit.", "android.view." }; public ParallaxFactory(ParallaxLayoutInflater inflater, LayoutInflater.Factory factory) { mInflater = inflater; this.factory = factory; } @Override public View onCreateView(String name, Context context, AttributeSet attrs) { View view = null; if (context instanceof LayoutInflater.Factory) { view = ((LayoutInflater.Factory) context).onCreateView(name, context, attrs); } if (factory != null && view == null) { view = factory.onCreateView(name, context, attrs); } if (view == null) { view = createViewOrFailQuietly(name, context, attrs); } if (view != null) { onViewCreated(view, context, attrs); } return view; } protected View createViewOrFailQuietly(String name, Context context, AttributeSet attrs) { if (name.contains(".")) { return createViewOrFailQuietly(name, null, context, attrs); } for (final String prefix : sClassPrefixList) { final View view = createViewOrFailQuietly(name, prefix, context, attrs); if (view != null) { return view; } } return null; } protected View createViewOrFailQuietly(String name, String prefix, Context context,AttributeSet attrs) { try { return mInflater.createView(name, prefix, attrs); } catch (Exception ignore) { return null; } } protected void onViewCreated(View view, Context context, AttributeSet attrs) { int[] attrIds = {R.attr.a_in, R.attr.a_out, R.attr.x_in, R.attr.x_out, R.attr.y_in, R.attr.y_out,}; TypedArray a = context.obtainStyledAttributes(attrs, attrIds); if (a != null) { if (a.length() > 0) { ParallaxViewTag tag = new ParallaxViewTag(); tag.alphaIn = a.getFloat(0, 0f); tag.alphaOut = a.getFloat(1, 0f); tag.xIn = a.getFloat(2, 0f); tag.xOut = a.getFloat(3, 0f); tag.yIn = a.getFloat(4, 0f); tag.yOut = a.getFloat(5, 0f); view.setTag(R.id.parallax_view_tag, tag); } a.recycle(); } }}主要看onViewCreated（）方法，可以看到，这里我们将对应的每个属性的值都set到了我们ParallaxViewTag中，我们接着看下面的代码，调用updateAdapterCount（）方法让适配器去更新adapter的数量，这里我们可以看到适配器是继承PagerAdapter类，用于ViewPager的适配器，这里使用LinkedList来存储View，这个方法很好，赞一下
//更新ViewPagerAdapter的数量 updateAdapterCount();//具体代码//被调用的时候好像是0 private void updateAdapterCount() { adapter.setCount(isLooping ? Integer.MAX_VALUE : pageCount); }//下面是adapter的具体代码package com.qianmo.xiaohongshuwelcome.parallaxpager;import android.content.Context;import android.support.v4.view.PagerAdapter;import android.view.View;import android.view.ViewGroup;import java.util.LinkedList;import static android.view.ViewGroup.LayoutParams;import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;public class ParallaxPagerAdapter extends PagerAdapter { private int count = 0; private final Context context; private final LinkedList<View> recycleBin = new LinkedList<View>(); public ParallaxPagerAdapter(Context context) { this.context = context; } public void setCount(int count) { this.count = count; } @Override public int getCount() { return count; } @Override public Object instantiateItem(ViewGroup container, int position) { View view; if (!recycleBin.isEmpty()) { view = recycleBin.pop(); } else { view = new View(context); view.setLayoutParams(new LayoutParams(MATCH_PARENT, MATCH_PARENT)); } container.addView(view); return view; } @Override public void destroyItem(ViewGroup container, int position, Object object) { View view = (View) object; container.removeView(view); recycleBin.push(view); } @Override public boolean isViewFromObject(View view, Object object) { return view.equals(object); }}我们继续往下看，后面的就是创建viewpager对象，并addview到主控件上，在attachOnPagerChangeListener（）方法中添加viewpager的滑动监听
/创建viewpagerviewPager = new ViewPager(getContext());viewPager.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));viewPager.setId(R.id.parallax_pager);//给viewpager添加滑动监听attachOnPageChangeListener();//设置适配器viewPager.setAdapter(adapter);//将viewpager添加到主控件中addView(viewPager, 0);这里我们在onPageScrollStateChanged（）方法判断是否开启下面小人行走的动画，通过onPageScrolled（）方法监听滑动的具体偏移量，通过view.setTranslationX（）方法来改变对应的属性
protected void attachOnPageChangeListener() { mCommonPageChangeListener = new ViewPager.OnPageChangeListener() { @Override public void onPageScrollStateChanged(int state) { Log.v(TAG, "onPageScrollStateChanged" + state); iv.setBackgroundResource(R.drawable.man_run); final AnimationDrawable animationDrawable = (AnimationDrawable) iv.getBackground(); switch (state) { case 0: //处于展示阶段 finishAnim(animationDrawable); break; case 1: //正在滑动 isEnd = false; animationDrawable.start(); break; case 2: //滑动完毕 finishAnim(animationDrawable); break; } } //判断是否还是在左边 boolean isleft = false; @Override public void onPageScrolled(int pageIndex, float offset, int offsetPixels) {// Log.v(TAG, "onPageScrolled" + pageIndex + " offset" + offset + " offsetPixels" + offsetPixels); if (offsetPixels < 10) { isleft = false; } if (pageCount > 0) { pageIndex = pageIndex % pageCount; } if (pageIndex == 3) { if (isleft) { } else { iv.setX(iv.getLeft() - offsetPixels); } } ParallaxViewTag tag; for (View view : parallaxViews) { tag = (ParallaxViewTag) view.getTag(R.id.parallax_view_tag); if (tag == null) { continue; } if ((pageIndex == tag.index - 1 || (isLooping && (pageIndex == tag.index - 1 + pageCount))) && containerWidth != 0) { // make visible view.setVisibility(VISIBLE); // slide in from right view.setTranslationX((containerWidth - offsetPixels) * tag.xIn); // slide in from top view.setTranslationY(0 - (containerWidth - offsetPixels) * tag.yIn); // fade in view.setAlpha(1.0f - (containerWidth - offsetPixels) * tag.alphaIn / containerWidth); } else if (pageIndex == tag.index) { // make visible view.setVisibility(VISIBLE); // slide out to left view.setTranslationX(0 - offsetPixels * tag.xOut); // slide out to top view.setTranslationY(0 - offsetPixels * tag.yOut); // fade out view.setAlpha(1.0f - offsetPixels * tag.alphaOut / containerWidth); } else { view.setVisibility(GONE); } } } @Override public void onPageSelected(int position) { Log.v(TAG, "onPageSelected" + position); currentPosition = position; } }; viewPager.setOnPageChangeListener(mCommonPageChangeListener); }4，这里基本上就把源码分析完了，so，既然分析完别人的源码了下面就是结合到自己项目中去用了，当我们，想要实现一个翻页从顶部斜飞入的view，那我们的布局文件代码可以如下：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="fill_parent" android:layout_height="fill_parent"android:background="@color/transparent"> <ImageView android:id="@+id/iv_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_centerHorizontal="true" android:layout_marginLeft="133dp" android:layout_marginTop="39dp" android:src="@drawable/ic_launcher" app:x_in="1" app:x_out="1" app:y_in="0.6" app:y_out="0.9"/> <ImageView android:id="@+id/iv_11" android:layout_width="44dp" android:layout_height="47dp" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="66dp" android:layout_marginLeft="140dp" android:src="@drawable/ic_launcher" app:x_in="1" app:x_out="1" app:y_in="-1.3" app:y_out="-1.3"/></RelativeLayout>关于怎么在Android应用中添加一个欢迎界面就分享到这里了，希望以上内容可以对大家有一定的帮助，可以学到更多知识。如果觉得文章不错，可以把它分享出去让更多的人看到。
