ImageLoader圖片載入
阿新 • • 發佈:2018-11-22
1.MainActivity頁面
package com.example.day07_imageloader01; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.widget.ListView; public class MainActivity extends AppCompatActivity { private ListView listView; private NewsAdaper mAdaper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //獲取資源id listView = findViewById(R.id.listview); //建立介面卡 mAdaper = new NewsAdaper(MainActivity.this); //賦給listview listView.setAdapter(mAdaper); infoData(); } private String urlStr = "http://api.expoon.com/AppNews/getNewsList/type/1/p/1"; //獲取資料的方法 private void infoData() { NetUtil.getInstance().getRequest(urlStr, NewsBean.class, new NetUtil.CallBack<NewsBean>() { @Override public void onSuccess(NewsBean o) { mAdaper.setmData(o.getData()); } }); } }
2.Bean類
package com.example.day07_imageloader01; import java.util.List; public class NewsBean { private List<DataBean> data; public List<DataBean> getData() { return data; } public void setData(List<DataBean> data) { this.data = data; } public static class DataBean { private String news_id; private String news_title; private String news_summary; private String pic_url; public String getNews_id() { return news_id; } public void setNews_id(String news_id) { this.news_id = news_id; } 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; } } }
3.介面卡類
package com.example.day07_imageloader01; 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.ImageScaleType; import com.nostra13.universalimageloader.core.display.CircleBitmapDisplayer; import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer; import com.nostra13.universalimageloader.core.display.RoundedBitmapDisplayer; import java.util.ArrayList; import java.util.List; public class NewsAdaper extends BaseAdapter { private List<NewsBean.DataBean> mData; private Context mContext; public NewsAdaper(Context mContext) { this.mContext = mContext; //初始化 mData = new ArrayList<>(); } public void setmData(List<NewsBean.DataBean> datas){ this.mData = datas; notifyDataSetChanged(); } @Override public int getCount() { return mData.size(); } @Override public NewsBean.DataBean getItem(int position) { return mData.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder; if(convertView == null){ //載入子佈局 convertView = LayoutInflater.from(mContext).inflate(R.layout.item,parent,false); //例項化 holder = new ViewHolder(convertView); }else{ holder = (ViewHolder) convertView.getTag(); } holder.bind(getItem(position)); return convertView; } //建立暫存器 class ViewHolder{ ImageView image; TextView title; TextView summary; //獲取資源id public ViewHolder(View convertView) { image = convertView.findViewById(R.id.image); title = convertView.findViewById(R.id.title); summary = convertView.findViewById(R.id.summary); //convertView.setTag(this); } //賦值 public void bind(NewsBean.DataBean item) { title.setText(item.getNews_title()); summary.setText(item.getNews_summary()); 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) //顯示圓形 // .displayer(new CircleBitmapDisplayer()) //顯示圓角 // .displayer(new RoundedBitmapDisplayer(10)) .displayer(new FadeInBitmapDisplayer(200)) .build(); ImageLoader.getInstance().displayImage(item.getPic_url(),image,options); } } }
4.工具類
package com.example.day07_imageloader01;
import android.annotation.SuppressLint;
import android.content.Context;
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.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class NetUtil {
//單例
private static NetUtil instance;
//私有構造方法
public NetUtil() {
}
//提供方法,獲得物件
public static NetUtil getInstance() {
if(instance == null){
instance = new NetUtil();
}
return instance;
}
//執行一個網路請求 返回string
public String getRequest(String urlStr){
String json = "";
try {
//定義url地址
URL url = new URL(urlStr);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//設定請求格式
urlConnection.setRequestMethod("GET");
//設定超時
urlConnection.setReadTimeout(5000);
urlConnection.setConnectTimeout(5000);
//獲取狀態碼
int responseCode = urlConnection.getResponseCode();
if(responseCode == 200){
json = stream2String(urlConnection.getInputStream());
}
} catch (Exception e) {
e.printStackTrace();
}
return json;
}
//將位元組流轉換為字元流
private String stream2String(InputStream is) throws IOException {
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
StringBuilder builder = new StringBuilder();
for (String tmp = br.readLine();tmp != null;tmp = br.readLine()){
builder.append(tmp);
}
return builder.toString();
}
//執行一個網路請求 返回bean
public <E> E getRequest(String urlStr,Class clazz){
String request = getRequest(urlStr);
E e = (E) new Gson().fromJson(request,clazz);
return e;
}
//定義一個介面
public interface CallBack<E>{
void onSuccess(E e);
}
//執行一個網路請求,通過回撥返回結果
@SuppressLint("StaticFieldLeak")
public void getRequest(String urlStr, final Class clazz, final CallBack callBack){
new AsyncTask<String,Void,Object>(){
@Override
protected Object doInBackground(String... strings) {
return getRequest(strings[0],clazz);
}
@Override
protected void onPostExecute(Object o) {
callBack.onSuccess(o);
}
}.execute(urlStr);
}
}
5.Application頁面初始化載入imageloader
package com.example.day07_imageloader01;
import android.app.Application;
import com.nostra13.universalimageloader.cache.disc.DiskCache;
import com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiskCache;
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 java.io.IOException;
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
//DiskCache
//MemoryCache
//DisplayImageOptions options = new DisplayImageOptions.Builder().build();
ImageLoaderConfiguration configuration = null;
configuration = new ImageLoaderConfiguration.Builder(App.this)
//配置磁碟快取
//.diskCache(new LruDiskCache(getCacheDir(),new HashCodeFileNameGenerator(),10*1024*1024))
.diskCacheSize(50*1204*1024)
//記憶體快取大小
// .memoryCache(new LruMemoryCache(10))
//.memoryCacheSize()
.memoryCacheSizePercentage(10)
//執行緒配置
// .tasksProcessingOrder()
//預設顯示設定
//.defaultDisplayImageOptions(options)
.build();
//初始化imageloder:只有第一次初始化有效果
ImageLoader.getInstance().init(configuration);
}
}
6.AndroidManifest.xml頁面
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.day07_imageloader01">
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:name=".App"
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>