首先看一下運作效果
主要目的:使用ImageLoader加載網絡圖檔資源進行展示圖檔首頁實作無限自動輪播的功能還有小圓點通過這一篇部落格可以學到很多東西
目錄結構隻能說清晰啊
話不多說直接上代碼
1首先使用GsonFormat插件直接封裝好bean
2主布局
<?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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.yamade.alongstorm.testmontha.MainActivity">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="200dp">
<android.support.v4.view.ViewPager
android:id="@+id/vp"
android:layout_width="match_parent"
android:layout_height="200dp"></android.support.v4.view.ViewPager>
<LinearLayout
android:id="@+id/ll"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_alignParentBottom="true"
android:layout_marginBottom="5dp"
android:orientation="horizontal"
android:padding="8dp" />
</RelativeLayout>
</RelativeLayout>
然後做一個小圓點的幫助類,裡邊需要傳四個參數
1上下文
2需要小圓點的viewpager
3繪制小圓點所在的線性布局
4小圓點的長度
package com.yamade.alongstorm.testmontha;
import android.content.Context;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Alongstorm on 2017/8/23,0023.
*/
public class ViewPagerIndicator implements ViewPager.OnPageChangeListener {
private Context context;
private ViewPager viewPager;
private LinearLayout dotLayout;
private int size;
private int img1 = R.mipmap.gouwuzy_16, img2 = R.mipmap.gouwuzy_17;
private int imgSize = 15;
private List<ImageView> dotViewLists = new ArrayList<>();
public ViewPagerIndicator(Context context, ViewPager viewPager, LinearLayout dotLayout, int size) {
this.context = context;
this.viewPager = viewPager;
this.dotLayout = dotLayout;
this.size = size;
for (int i = 0; i < size; i++) {
ImageView imageView = new ImageView(context);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
//為小圓點左右添加間距
params.leftMargin = 10;
params.rightMargin = 10;
//手動給小圓點一個大小
params.height = imgSize;
params.width = imgSize;
if (i == 0) {
imageView.setBackgroundResource(img1);
} else {
imageView.setBackgroundResource(img2);
}
//為LinearLayout添加ImageView
dotLayout.addView(imageView, params);
dotViewLists.add(imageView);
}
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
for (int i = 0; i < size; i++) {
//選中的頁面改變小圓點為選中狀态,反之為未選中
if ((position % size) == i) {
((View) dotViewLists.get(i)).setBackgroundResource(img1);
} else {
((View) dotViewLists.get(i)).setBackgroundResource(img2);
}
}
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
下面是主Activity,這個就比較厲害了
package com.yamade.alongstorm.testmontha;
import android.os.AsyncTask;
import android.os.Handler;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import com.google.gson.Gson;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.yamade.alongstorm.testmontha.bean.DataBean;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
ViewPager vp;
DataBean db;
List<DataBean> datas;
MyAdapter adapter;
List<String> pic;
int lun;
private boolean isAutoPlay;
private LinearLayout ll;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
initData();
final Handler handler=new Handler();
lun=0;
handler.postDelayed(new Runnable() {
@Override
public void run() {
vp.setCurrentItem(lun);
lun++;
handler.postDelayed(this,1000);
}
}, 1000);
vp.setOnPageChangeListener(new ViewPagerIndicator(this,vp,ll,6));
}
private void initData() {
new AsyncTask<String, String, String>() {
@Override
protected String doInBackground(String... strings) {
String res=getData();
return res;
}
@Override
protected void onPostExecute(String s) {
Gson gson=new Gson();
db=gson.fromJson(s,DataBean.class);
datas.add(db);
for(int j=0;j<datas.get(0).getResult().getAdvs().size();j++) {
String pict=datas.get(0).getResult().getAdvs().get(j).getPic();
pic.add(pict);
}
adapter=new MyAdapter();
vp.setAdapter(adapter);
adapter.notifyDataSetChanged();
super.onPostExecute(s);
}
}.execute("");
}
class MyAdapter extends PagerAdapter{
@Override
public int getCount() {
return Integer.MAX_VALUE;
//return pic.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view==object;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
//若position超過mDataList.size(),會發生越界異常,是以這裡每次超過size又從0開始計算位置
position = position % pic.size();
ImageView img=new ImageView(MainActivity.this);
ImageLoader.getInstance().displayImage(pic.get(position),img);
container.addView(img);
return img;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
position = position % datas.size();
container.removeView((View)object);
// super.destroyItem(container, position, object);
}
}
private void initView() {
vp= (ViewPager) findViewById(R.id.vp);
ll = (LinearLayout) findViewById(R.id.ll);
datas=new ArrayList<DataBean>();
pic=new ArrayList<String>();
}
public String getData() {
String result="";
String path="http://www.babybuy100.com/API/getShopOverview.ashx";
try {
URL url=new URL(path);
HttpURLConnection conn= (HttpURLConnection) url.openConnection();
conn.setConnectTimeout(5000);
conn.setReadTimeout(5000);
conn.setRequestMethod("GET");
if (conn.getResponseCode()==200) {
InputStream is = conn.getInputStream();
ByteArrayOutputStream bos=new ByteArrayOutputStream();
int len=-1;
byte[] buff=new byte[1024];
while((len=is.read(buff))!=-1){
bos.write(buff,0,len);
}
byte[] bytes=bos.toByteArray();
result=new String(bytes);
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
}
肯定還會有人問這個這個ImageLoader怎麼用啊
直接對你們說了
package com.yamade.alongstorm.testmontha;
import android.app.Application;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
/**
* Created by Alongstorm on 2017/8/23,0023.
*/
public class MyApplication extends Application {
@Override
public void onCreate() {
//初始化imageloader
//1 使用一個預設的圖檔顯示配置
DisplayImageOptions options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.mipmap.ic_launcher)
.displayer(new FadeInBitmapDisplayer(3000))
.build();
//2 初始化config配置
ImageLoaderConfiguration configs=new ImageLoaderConfiguration.Builder(this)
.threadPoolSize(4)//線程池的數量
.memoryCacheExtraOptions(480,800)
.defaultDisplayImageOptions(options)
.build();
ImageLoader.getInstance().init(configs);
super.onCreate();
}
}
如果覺得對你有幫助,不妨小額打賞一下呗,錢多少無所謂,我看看有多少人支援