網路載入圖片 展示圖片 樣式
阿新 • • 發佈：2018-11-19
MainActivity
package com.example.imageloader; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.ListView; import com.nostra13.universalimageloader.core.ImageLoader; public class MainActivity extends AppCompatActivity { private ListView news; private MyBaseAdafter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); news = findViewById(R.id.news); mAdapter = new MyBaseAdafter(this); news.setAdapter(mAdapter); findViewById(R.id.left).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //載入資料 NetUtil.getInstance().getRequest("http://api.expoon.com/AppNews/getNewsList/type/1/p/1", Bean.class, new NetUtil.Callbak<Bean>() { @Override public void onSuccess(Bean o) { mAdapter.setListData(o.getData()); } }); } }); } }
BaseAdapter頁面
package com.example.imageloader; import android.content.Context; import android.graphics.Bitmap; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.ImageView; import android.widget.TextView; import com.nostra13.universalimageloader.core.DisplayImageOptions; import com.nostra13.universalimageloader.core.ImageLoader; import com.nostra13.universalimageloader.core.assist.FailReason; import com.nostra13.universalimageloader.core.assist.ImageScaleType; import com.nostra13.universalimageloader.core.display.BitmapDisplayer; import com.nostra13.universalimageloader.core.display.CircleBitmapDisplayer; import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer; import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer; import com.nostra13.universalimageloader.core.listener.ImageLoadingListener; import java.util.ArrayList; import java.util.List; public class MyBaseAdafter extends BaseAdapter { private Context context; private List<Bean.DataBean>mlist; public MyBaseAdafter(Context context) { this.context = context; mlist = new ArrayList<>(); } public void setListData(List<Bean.DataBean> list){ this.mlist = list; notifyDataSetChanged(); } @Override public int getCount() { return mlist.size(); } @Override public Bean.DataBean getItem(int position) { return mlist.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { final ViewHoder viewHoder; if(convertView==null){ convertView = LayoutInflater.from(context).inflate(R.layout.item,parent,false); viewHoder = new ViewHoder(); viewHoder.textView1 = convertView.findViewById(R.id.textview1); viewHoder.textView2 = convertView.findViewById(R.id.textview2); viewHoder.imageView = convertView.findViewById(R.id.imageview); convertView.setTag(viewHoder); }else{ viewHoder = (ViewHoder) convertView.getTag(); } viewHoder.textView1.setText(mlist.get(position).getNews_title()); viewHoder.textView2.setText(mlist.get(position).getNews_summary()); // 1280 * 720 -> 1280 * 720 * 每個畫素佔用位元組數16 // //RGB_565 red green blue 紅綠藍 的顏色 r佔5byte g佔6byte b佔5byte //A RGB_4444 A RGB_8888 //ALPHA_8 //BitmapDisplayer DisplayImageOptions options = new DisplayImageOptions.Builder() //配置色彩模式 .bitmapConfig(Bitmap.Config.RGB_565) //配置 是否快取 .cacheInMemory(true) .cacheOnDisk(true) //配置 預設顯示 .showImageOnLoading(R.mipmap.ic_launcher) .showImageOnFail(R.mipmap.ic_launcher) .showImageForEmptyUri(R.mipmap.ic_launcher) //配置圖片如何縮放 .imageScaleType(ImageScaleType.EXACTLY) //顯示效果:圓形 //.displayer(new CircleBitmapDisplayer()) //圓角 //.displayer(new RoundedBitmapDisplayer(8)) .displayer(new FadeInBitmapDisplayer(2000)) .build(); //載入圖片 ImageLoader .getInstance() .displayImage(getItem(position).getPic_url(), viewHoder.imageView, options); //只加載圖片 //回撥返回bitmap //ImageLoader.getInstance().loadImage(); return convertView; } class ViewHoder{ private TextView textView1,textView2; private ImageView imageView; } }
工具類NetUtil
package com.example.yu.zixun01; import android.annotation.SuppressLint; import android.os.AsyncTask; import com.google.gson.Gson; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.util.List; public class NetUtil { private static NetUtil netUtil; public static NetUtil getInstance(){ if(netUtil==null){ netUtil=new NetUtil(); } return netUtil; } public interface CallBack<T>{ void onsuccess(T t); } @SuppressLint("StaticFieldLeak") public void getRequest(final String strurl, final Class bean, final CallBack callBack) { new AsyncTask<String, Void, Object>() { @Override protected Object doInBackground(String... strings) { return getRequest(strurl,bean); } @Override protected void onPostExecute(Object o) { callBack.onsuccess(o); } }.execute(strurl, ""); } public <T> T getRequest(String urlStr,Class clazz){ return (T) new Gson().fromJson(getRequest(urlStr),clazz); } public String getRequest(String strurl){ String result = ""; try { URL url = new URL(strurl); HttpURLConnection urlConnection = null; urlConnection = (HttpURLConnection) url.openConnection(); urlConnection.setRequestMethod("GET"); urlConnection.setConnectTimeout(5000); urlConnection.setReadTimeout(5000); int responseCode = urlConnection.getResponseCode(); if (responseCode == 200) { result = stream2String(urlConnection.getInputStream()); } } catch (IOException e) { e.printStackTrace(); } return result; } public String stream2String(InputStream inputStream) throws IOException { StringBuilder sb = new StringBuilder(); BufferedReader br = new BufferedReader(new InputStreamReader(inputStream)); for (String tmp = br.readLine(); tmp != null; tmp = br.readLine()) { sb.append(tmp); } return sb.toString(); } }
Bean類
package com.example.imageloader;
import java.util.List;
public class Bean {
/**
* status : 1
* info : 獲取內容成功
* data : [{"news_id":"13811","news_title":"深港澳臺千里連線，嘉年華會今夏入川","news_summary":"6月17\u201420日，\u201c2016成都深港澳臺嘉年華會\u201d(簡稱嘉年華會)將在成都世紀城國際會展中心舉辦。其主辦方勵展華博借力旗","pic_url":"http://f.expoon.com/sub/news/2016/01/21/887844_230x162_0.jpg"},]
*/
private List<DataBean> data;
public List<DataBean> getData() {
return data;
}
public void setData(List<DataBean> data) {
this.data = data;
}
public static class DataBean {
/**
* news_id : 13811
* news_title : 深港澳臺千里連線，嘉年華會今夏入川
* news_summary : 6月17—20日，“2016成都深港澳臺嘉年華會”(簡稱嘉年華會)將在成都世紀城國際會展中心舉辦。其主辦方勵展華博借力旗
* pic_url : http://f.expoon.com/sub/news/2016/01/21/887844_230x162_0.jpg
*/
private String news_title;
private String news_summary;
private String pic_url;
public String getNews_title() {
return news_title;
}
public void setNews_title(String news_title) {
this.news_title = news_title;
}
public String getNews_summary() {
return news_summary;
}
public void setNews_summary(String news_summary) {
this.news_summary = news_summary;
}
public String getPic_url() {
return pic_url;
}
public void setPic_url(String pic_url) {
this.pic_url = pic_url;
}
}
}
App頁面
package com.example.imageloader;
import android.app.Application;
import android.os.Environment;
import com.nostra13.universalimageloader.cache.disc.DiskCache;
import com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiskCache;
import com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator;
import com.nostra13.universalimageloader.cache.disc.naming.HashCodeFileNameGenerator;
import com.nostra13.universalimageloader.cache.memory.MemoryCache;
import com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
import java.io.IOException;
//優先於所有頁面(Activity)建立
//主要負責應用全域性初始化
//該物件也是一個context
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
//ctrl + h 檢視累的繼承結構
//MemoryCache
//DiskCache
//FileNameGenerator
//怎麼呼叫api
//要什麼引數
//怎麼給這個引數
//Builder
//構建模式
//鏈式呼叫
//全域性配置
ImageLoaderConfiguration configuration = null;
DisplayImageOptions options = new DisplayImageOptions.Builder()
.build();
//try {
//
configuration = new ImageLoaderConfiguration.Builder(this)
//配置:記憶體 磁碟 快取
//.memoryCache(new LruMemoryCache())
//.memoryCacheSize()
//記憶體快取大小
.memoryCacheSizePercentage(10)
//配置磁碟快取:目錄 檔名生成 大小
//.diskCache(new LruDiskCache(getCacheDir(), new HashCodeFileNameGenerator(), 10*1024*1024))
.diskCacheSize(50*1024*1024)
//執行緒配置
//任務優先順序配置
//FIFO
//載入圖片1 2 3 4 5
//LIFO
//.tasksProcessingOrder(QueueProcessingType.)
//預設顯示配置
//.defaultDisplayImageOptions(options)
.build();
//} catch (IOException e) {
// e.printStackTrace();
//}
//初始化:只有第一次初始化有效果
ImageLoader.getInstance().init(configuration);
//無效果
//ImageLoader.getInstance().init(null);
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.imageloader">
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:name=".App"//註冊activity
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>
</application>
</manifest>
需要第三方jar包 gson , image-loader