闪屏界面的实现分析

来源：互联网发布：佳能dpp mac 编辑：程序博客网时间：2024/06/04 23:30

实现的效果：

主要代码及分析：

1.引导界面整体布局，在布局文件中首先加入ViewPager 这个组件，然后加入四个ImageView 组件，代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".GuideActivit<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".GuideActivity" >    <android.support.v4.view.ViewPager       android:id="@+id/vpGuide"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_alignParentLeft="true"       android:layout_alignParentTop="true"        >        </android.support.v4.view.ViewPager>    <LinearLayout        android:id="@+id/linearLayout1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="40dp" >        <ImageView        android:id="@+id/guide_dot1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/bg_point_selected"         />        <ImageView            android:id="@+id/guide_2"             android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"                         />        <ImageView            android:id="@+id/guide_3"            android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"             />        <ImageView            android:id="@+id/guide_4"             android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"            />    </LinearLayout></RelativeLayout>y" >    <android.support.v4.view.ViewPager       android:id="@+id/vpGuide"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_alignParentLeft="true"       android:layout_alignParentTop="true"        >        </android.support.v4.view.ViewPager>    <LinearLayout        android:id="@+id/linearLayout1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentBottom="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="40dp" >        <ImageView        android:id="@+id/guide_dot1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="@drawable/bg_point_selected"         />        <ImageView            android:id="@+id/guide_2"             android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"            />        <ImageView            android:id="@+id/guide_3"            android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"             />        <ImageView            android:id="@+id/guide_4"             android:layout_marginLeft="10dp"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:background="@drawable/bg_point"            />    </LinearLayout></RelativeLayout>

其中bg_point_selected的代码：

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >    <solid android:color="#427AB7" /><sizeandroid:height="8dp"android:width="8dp" /></shape>

bg_point文件如下：

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"><!-- 未被选中 --><solid android:color="@android:color/black" /><sizeandroid:height="8dp"android:width="8dp" />    </shape>

2.切换布局文件：

view1_of_pager.xml:

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@drawable/guide_2"    android:orientation="vertical" >    </LinearLayout>

view2_of_pager.xml文件、view3_of_pager.xml文件与上的代码相同，只是图片不同。
view4_of_pager.xml文件：

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@drawable/guide_1"    android:orientation="vertical" >  <TextView       android:id="@+id/tvGO"      android:layout_width="wrap_content"      android:layout_height="wrap_content"      android:layout_alignParentBottom="true"      android:layout_alignParentRight="true"      android:layout_marginBottom="16dp"      android:layout_marginRight="19dp"      android:background="@drawable/start_select"      android:gravity="center"      android:text="GO"      android:textColor="#ffffff"      android:textSize="30sp"      /></RelativeLayout>

3.编写GuideAdapter类：

package com.example.cl;import java.util.List;import android.support.v4.view.PagerAdapter;import android.util.Log;import android.view.View;import android.view.ViewGroup;public class GuideAdapter extends PagerAdapter {private List<View> views;public GuideAdapter(List<View> views) {this.views = views;}@Overridepublic int getCount() {return  views.size();}@Overridepublic boolean isViewFromObject(View view, Object object) {return view==object;}@Overridepublic void destroyItem(ViewGroup container, int position, Object object) {View view=views.get(position);container.removeView(view);}@Overridepublic Object instantiateItem(ViewGroup container, int position) {container.addView(views.get(position));return views.get(position);}    }<span style="color:#ff0000;"></span>

这里特别讲一下PageAdapter——PageView的适配器：

适配器想必大家都不莫生，在ListView中也有适配器，listView通过重写GetView（）函数来获取当前要加载的Item。而PageAdapter不太相同，毕竟PageAdapter是单个VIew的合集。

PageAdapter 必须重写的四个函数：

boolean isViewFromObject(View arg0, Object arg1)
int getCount()
void destroyItem(ViewGroup container, int position,Object object)
Object instantiateItem(ViewGroup container, int position)

先看看各个函数，我们上面都做了什么吧：

@Overridepublic int getCount() {return  views.size();}

getCount():返回要滑动的VIew的个数

@Overridepublic void destroyItem(ViewGroup container, int position, Object object) {View view=views.get(position);container.removeView(view);}

destroyItem（）：从当前container中删除指定位置（position）的View;

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

这样重写

4.修改GuideActivity：

public class GuideActivity extends Activity {   private List<View> guideViews;   private ViewPager vpGuide;   private int[]guide_dots={R.id.guide_dot1,R.id.guide_2,R.id.guide_3,R.id.guide_4};   private ImageView[] dots;   private TextView tvGO;   @Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_guide);initGuideViews();initDots();setListeners();}private void setListeners() {vpGuide.setOnPageChangeListener(new OnPageChangeListener() {@Overridepublic void onPageSelected(int position) {for(int i=0;i<guide_dots.length;i++){if(position==i){dots[i].setImageResource(R.drawable.bg_point_selected);}else{dots[i].setImageResource(R.drawable.bg_point);}}}@Overridepublic void onPageScrolled(int arg0, float arg1, int arg2) {// TODO Auto-generated method stub}@Overridepublic void onPageScrollStateChanged(int arg0) {}});tvGO.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubIntent intent=new Intent(GuideActivity.this,LoginActivity.class);    startActivity(intent);}});}private void initDots() {dots=new ImageView[4];for(int i=0;i<dots.length;i++){dots[i]=(ImageView) findViewById(guide_dots[i]);}}private void initGuideViews() {vpGuide=(ViewPager) findViewById(R.id.vpGuide);//准备好切换的viewguideViews=new ArrayList<View>();LayoutInflater layoutInfalter=LayoutInflater.from(this);guideViews.add(layoutInfalter.inflate(R.layout.view1_of_pager, null));guideViews.add(layoutInfalter.inflate(R.layout.view2_of_pager, null));guideViews.add(layoutInfalter.inflate(R.layout.view3_of_pager, null));<strong><span style="color:#ff0000;">View view4=layoutInfalter.inflate(R.layout.view4_of_pager, null);       guideViews.add(view4);       tvGO=(TextView) view4.findViewById(R.id.tvGO);</span></strong>

GuideAdapter guideAdapter=new GuideAdapter(guideViews);vpGuide.setAdapter(guideAdapter);}}

以上为实现闪屏界面的主要代码，还不完善，继续加油！！！！

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