Banner 的使用（网络请求图片无线轮播demo）

记得在 Gradle  文件中  添加依赖

compile 'com.youth.banner:banner:1.4.9'

compile 'com.google.code.gson:gson:2.2.4'   //gson 的jra 包compile files('libs/universal-image-loader-1.9.3.jar')  //ImagerLoader 的依赖

还有就是权限了   各种权限  在这里就不一一说了。。。

首先是  XML 文件

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"    android:layout_width="match_parent" android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.bawei.bannerdemo.MainActivity"><com.youth.banner.Banner    android:layout_width="match_parent"    android:layout_height="150dp"    android:id="@+id/bnn"></com.youth.banner.Banner></RelativeLayout>

 Activity  代码

package com.bawei.bannerdemo;import android.os.AsyncTask;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import com.google.gson.Gson;import com.youth.banner.Banner;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private Banner bnn;    List<String> imglist;     String jsonurl="http://www.yulin520.com/a2a/impressApi/news/mergeList?pageSize=10&page=1";    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }    private void initView() {        bnn = (Banner) findViewById(R.id.bnn);        new AsyncTask<String, Integer, String>() {            @Override            protected String doInBackground(String... strings) {                String getjsonstr = new Utlis().getjsonstr(jsonurl);                return getjsonstr;            }            @Override            protected void onPostExecute(String s) {                super.onPostExecute(s);                List<User.DataBean> list = new Gson().fromJson(s, User.class).getData();                imglist=new ArrayList<String>();                for (int i=0;i<list.size();i++){                    imglist.add(list.get(i).getImg());                }                bnn.setDelayTime(1000);                bnn.setImageLoader(new getimg());                bnn.setImages(imglist);               bnn.start();            }        }.execute();      //  bnn.setDelayTime(100)    }}

Utlis  类 封装了  网络请求的工具类

package com.bawei.bannerdemo;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;/** * Created by  on 2017/12/15. */public class Utlis {    public  String getjsonstr(String name){        String jsonstr="";        try {            URL url=new URL(name);           HttpURLConnection conn= (HttpURLConnection) url.openConnection();            conn.setConnectTimeout(5000);            conn.setReadTimeout(5000);            int code = conn.getResponseCode();            if(code==200){                InputStream is = conn.getInputStream();                byte arr[]=new byte[1024];                int len=0;                while((len=is.read(arr))!=-1){                    String s = new String(arr, 0, len);                    jsonstr+=s;                }            }        } catch (MalformedURLException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return jsonstr;    }}