轮播图Banner实现-优快云博客

本文介绍了一种基于Android平台的轮播图Banner实现方式，包括布局文件、主要逻辑处理、自定义ViewPager及图片加载等关键技术细节。

//主要逻辑处理的布局（mybanner_layout）

<?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="200dp"> <android.support.v4.view.ViewPager android:layout_width="match_parent" android:layout_height="200dp" android:id="@+id/viewpager"></android.support.v4.view.ViewPager> <LinearLayout android:orientation="horizontal" android:gravity="center" android:id="@+id/ll_points" android:layout_width="match_parent" android:layout_height="30dp" android:layout_alignParentBottom="true"></LinearLayout></RelativeLayout>

//主要的逻辑处理

package com.example.lenovo.day0609_monizhoukao1.view.LunBo;

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;

import com.example.lenovo.day0609_monizhoukao1.R;
import com.example.lenovo.day0609_monizhoukao1.bean.LunBoBean;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by lenovo on 2018/6/9.
 */

public class MyBanner extends RelativeLayout {

    private LinearLayout linearLayout;
    private ViewPager viewPager;
    private MyHandler myHandler = new MyHandler();
    private List<ImageView> points;
    private List<LunBoBean.DataBean> lists;
    private String url;
    private static final String TAG = "MyBanner";

    public MyBanner(Context context) {
        this(context, null);
    }

    public MyBanner(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyBanner(final Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        View view = View.inflate(context, R.layout.mybanner_layout, this);
        viewPager = (ViewPager) view.findViewById(R.id.viewpager);
        linearLayout = (LinearLayout) view.findViewById(R.id.ll_points);
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageSelected(int position) {
                viewPager.setOnTouchListener(new View.OnTouchListener() {
                    @Override
                    public boolean onTouch(View v, MotionEvent event) {
                        Intent in = new Intent(context, DetailActivity.class);
                        in.putExtra("url", url);
                        context.startActivity(in);
                        return false;
                    }
                });

                position = position % points.size();
                for (int i = 0; i < points.size(); i++) {
                    if (i == position) {
                        points.get(i).setSelected(true);
                    } else {
                        points.get(i).setSelected(false);
                    }
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
    } //设置适配器

    public void setMyAdapter(Context context, List<ImageView> list, String url) {
        this.url = url;
        Log.d(TAG, "setMyAdapter: ==============" + url);
        MyAdapter myAdapter = new MyAdapter(context, list);
        viewPager.setAdapter(myAdapter);
        //设置小圆点
        points = new ArrayList<>();
        for (int i = 0; i < list.size(); i++) {
            ImageView point = new ImageView(context);
            point.setImageResource(R.drawable.circle_selector);
            linearLayout.addView(point);
            points.add(point);
        }
        //默认第一个选中
        points.get(0).setSelected(true);
    }

    //开启自动轮播
    public void startPlay() {
        myHandler.sendEmptyMessageDelayed(0, 1000);
    }

    //关闭自动轮播
    public void stopPlay() {
        myHandler.removeCallbacksAndMessages(null);
    }

    class MyAdapter extends PagerAdapter {
        private Context context;
        private List<ImageView> list;

        public MyAdapter(Context context, List<ImageView> list) {
            this.context = context;
            this.list = list;
        }

        @Override
        public int getCount() {
            return Integer.MAX_VALUE;
        }

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

        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            position = position % list.size();
            ImageView imageView = list.get(position);
            container.addView(imageView);
            return imageView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            container.removeView((ImageView) object);
        }
    }

    class MyHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            int currentItem = viewPager.getCurrentItem();
            currentItem++;
            viewPager.setCurrentItem(currentItem);
            myHandler.sendEmptyMessageDelayed(0, 1000);
        }
    }
}

//外部取地址的方法

package com.example.zhoukao_moni;/** * Created by lenovo on 2018/4/13. */public class HttpConfig { public static String url = "http://120.27.23.105/ad/getAd";}

//主方法的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent" tools:context="com.example.zhoukao_moni.MainActivity">

    <com.example.zhoukao_moni.MyBanner
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:id="@+id/banner"></com.example.zhoukao_moni.MyBanner>

</LinearLayout>

//主方法

package com.example.lenovo.day0609_monizhoukao1.view;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.ImageView;

import com.bumptech.glide.Glide;
import com.example.lenovo.day0609_monizhoukao1.R;
import com.example.lenovo.day0609_monizhoukao1.bean.LunBoBean;
import com.example.lenovo.day0609_monizhoukao1.http.HttpConig;
import com.example.lenovo.day0609_monizhoukao1.view.LunBo.MyBanner;
import com.google.gson.Gson;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private MyBanner myBanner;
    private MyHandler myHandler = new MyHandler();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initViews();
        initDatas();
    }

    private void initDatas() {
        OkHttpClient okHttpClient = new OkHttpClient();
        Request request = new Request.Builder().url(HttpConig.goods_url).build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String json = response.body().string();
                Message message = myHandler.obtainMessage();
                message.obj = json;
                myHandler.sendMessage(message);
            }
        });
    }

    private void initViews() {
        myBanner = (MyBanner) findViewById(R.id.banner);
    }

    class MyHandler extends Handler {
        private String url;

        @Override
        public void handleMessage(Message msg) {
            String json = (String) msg.obj;
            Gson gson = new Gson();
            LunBoBean lunBoBean =gson.fromJson(json, LunBoBean.class);
            List<LunBoBean.DataBean> list = lunBoBean.getData();
            List<ImageView> images = new ArrayList<>();
            for (int i = 0; i < list.size(); i++) {
                int type = list.get(i).getType();
                if (type == 0) {
                    url = list.get(i).getUrl();
                }
                Log.d(TAG, "handleMessage:-------------------******** " + url);
                String icon = list.get(i).getIcon();
                ImageView imageView = new ImageView(MainActivity.this);
                Glide.with(MainActivity.this).load(icon).into(imageView);
                images.add(imageView);
            }
            //Log.d(TAG, "handleMessage:------******-------------******** "+urlStr);
            myBanner.setMyAdapter(MainActivity.this, images, url);
            myBanner.startPlay();
        }
    }
}

//跳转的页面布局（activity_detail）

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

//跳转的页面

package com.example.zhoukao_moni;import android.content.Intent;import android.os.Bundle;import android.support.annotation.Nullable;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.webkit.WebView;/** * Created by lenovo on 2018/4/13. */public class DetailActivity extends AppCompatActivity{ private static final String TAG = "DetailActivity"; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_detail); Intent intent = getIntent(); String url = intent.getStringExtra("url"); Log.d(TAG, "onCreate:========= "+url); /*List<Bean.DataBean> list=new ArrayList<>(); for (int i = 0 ; i<list.size();i++) { String url1 = list.get(i).getUrl(); //Toast.makeText(DetailActivity.this,url1, Toast.LENGTH_LONG).show();// Log.d() }*/ WebView wv = (WebView) findViewById(R.id.wv); wv.getSettings().setJavaScriptEnabled(true); wv.loadUrl(url); }}

//圆点等的布局

//circle_selector

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/circle_press" android:state_selected="true" />
    <item android:drawable="@drawable/circle_normal" android:state_selected="false" />

</selector>

//circle_press

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">

    <size
        android:width="20dp"
        android:height="20dp" />
    <solid android:color="#00ff00" />

</shape>

//circle_normal

<?xml version="1.0" encoding="utf-8"?>
<shape
    android:shape="oval"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <size android:width="20dp" android:height="20dp"/>
    <solid android:color="#55999999"/>

</shape>

//权限配置

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.zhoukao_moni"> <uses-permission android:name="android.permission.INTERNET"></uses-permission> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".DetailActivity"></activity> </application></manifest>

//需要添加的依赖

compile 'com.google.code.gson:gson:2.6.2'

compile 'com.squareup.okhttp3:okhttp:3.3.0'

compile 'com.github.bumptech.glide:glide:3.7.0'

轮播图的点击跳转