ViewPager实现可以自动滚动的广告展示

来源：互联网发布：什么叫绿鞋机制知乎编辑：程序博客网时间：2024/05/18 09:07

广告展示用 ViewPager + PagerAdapter 实现，自动滚动直接用postDelayed实现。

指示器用的是系统的RadioButton，不是很和谐，可以自己重写一个。

要注意的是：postDelayed不要重复new Runnable，不然手动滑动的时候会产生很多个runnable，会出现乱滚动。

不知道RadioGroup为什么不能这check(1)，这里只能默认选择最后一个。

效果图如下：

MainActivity.java

package myviewpager.xiaopan.com.myviewpager;import android.support.v4.view.ViewPager;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.MotionEvent;import android.view.View;import android.widget.RadioButton;import android.widget.RadioGroup;import java.util.ArrayList;public class MainActivity extends AppCompatActivity {    private ViewPager vpShow ;    private ShowViewPagerAdapter showAdapter;    private ArrayList<AdBean> arr_Ads;    private RadioGroup rgCursor;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        arr_Ads = new ArrayList<>();        arr_Ads.add(new AdBean("第一幅广告图",R.drawable.pic1));        arr_Ads.add(new AdBean("第二幅广告图",R.drawable.pic2));        arr_Ads.add(new AdBean("第三幅广告图",R.drawable.pic3));        initView();    }    private void initView(){        vpShow = (ViewPager) findViewById(R.id.vp_show);        showAdapter = new ShowViewPagerAdapter(this,arr_Ads);        vpShow.setAdapter(showAdapter);        rgCursor = (RadioGroup) findViewById(R.id.rg_cursor);        for(int i = 0; i < arr_Ads.size(); i++){            RadioButton rb = new RadioButton(this);            rb.setId(i); rb.setClickable(false);            rgCursor.addView(rb);            rgCursor.check(i);        }        vpShow.setOnTouchListener(new View.OnTouchListener() {            @Override            public boolean onTouch(View view, MotionEvent motionEvent) {                if(motionEvent.getAction()== MotionEvent.ACTION_DOWN){                    doAutoScroll(false);                }else if(motionEvent.getAction()== MotionEvent.ACTION_UP){                    doAutoScroll(true);                }                return false; // 不能消费掉，还要响应滑动等其它事件            }        });        vpShow.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {//                Log.d("onPageScrolled","="+position);            }            @Override            public void onPageSelected(final int position) {                Log.d("OnPageSelected","="+position);                rgCursor.check(position);                doAutoScroll(true);            }            @Override            public void onPageScrollStateChanged(int state) {//                Log.d("PageScrollStateChanged","="+state);            }        });        doAutoScroll(true);    }    Runnable autoScroll = new Runnable() {        @Override        public void run() {            int currPos = vpShow.getCurrentItem();            vpShow.setCurrentItem(currPos>=arr_Ads.size()-1?0:currPos+1);        }    };    private void doAutoScroll(boolean bAuto){        Log.d("doAutoScroll"," = "+bAuto);        vpShow.removeCallbacks(autoScroll);        if(bAuto){            vpShow.postDelayed(autoScroll,6000);        }    }    class AdBean{        public String strTitle;        public int resId;        public AdBean(String strTitle, int resId){            this.strTitle = strTitle;            this.resId = resId;        }    }}

适配器
ShowViewPagerAdapter.java

package myviewpager.xiaopan.com.myviewpager;import android.content.Context;import android.support.v4.view.PagerAdapter;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import java.util.ArrayList;/** * Created by Pansing on 2015/7/13. */public class ShowViewPagerAdapter extends PagerAdapter {    private Context context;    private ArrayList<MainActivity.AdBean> arr_Ads;    public ShowViewPagerAdapter(Context context, ArrayList<MainActivity.AdBean> arr_Ads){        this.context = context;        this.arr_Ads = arr_Ads;    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView((View)object);    }    @Override    public int getItemPosition(Object object) {        return super.getItemPosition(object);    }    @Override    public void notifyDataSetChanged() {        super.notifyDataSetChanged();    }    @Override    public int getCount() {        if(arr_Ads==null){            return 0;        }        return arr_Ads.size();    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        View view = View.inflate(context,R.layout.view_show_item,null);        ImageView ivShow = (ImageView) view.findViewById(R.id.iv_show_item);        TextView tvTitle = (TextView) view.findViewById(R.id.tv_title_item);        ivShow.setImageResource(arr_Ads.get(position).resId);        tvTitle.setText(arr_Ads.get(position).strTitle);        container.addView(view);        return view;    }    @Override    public boolean isViewFromObject(View view, Object obj) {        return view == obj;    }}

布局文件activity_main.xml

<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" android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">    <android.support.v4.view.ViewPager        android:id="@+id/vp_show"        android:layout_width="match_parent"        android:layout_height="200dp">    </android.support.v4.view.ViewPager>    <RadioGroup        android:id="@+id/rg_cursor"        android:layout_width="wrap_content"        android:layout_height="20dp"        android:padding="5dp"        android:layout_alignBottom="@id/vp_show"        android:layout_alignRight="@id/vp_show"        android:orientation="horizontal">    </RadioGroup></RelativeLayout>

Item布局文件

<?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">    <ImageView        android:id="@+id/iv_show_item"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:scaleType="fitXY" />    <TextView        android:id="@+id/tv_title_item"        android:layout_alignParentBottom="true"        android:layout_width="match_parent"        android:layout_height="34dp"        android:gravity="center"        android:textColor="@android:color/white"        android:background="#A0333333" /></RelativeLayout>

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