imageloader圖片載入+將圖片快取到sd卡
阿新 • • 發佈：2018-11-22
1.mainActivity頁面
package com.example.guoxinyu20181108; 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); //賦值給listview listView.setAdapter(mAdaper); infoData(); } private String urlStr = "http://api.expoon.com/AppNews/getNewsList/type/1/p/1"; private void infoData() { NetUtil.getInstance().getResult(urlStr, NewsBean.class, new NetUtil.CallBack<NewsBean>() { @Override public void onSuccess(NewsBean o) { mAdaper.setmData(o.getData()); } }); } }
2.Bean類
package com.example.guoxinyu20181108; 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.guoxinyu20181108; 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.display.BitmapDisplayer; import com.nostra13.universalimageloader.core.display.CircleBitmapDisplayer; 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){ convertView = LayoutInflater.from(mContext).inflate(R.layout.item,parent,false); //例項化 holder = new ViewHolder(convertView); }else{ //複用 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) //讓圖片進行sdcard快取 .cacheOnDisk(true) //讓圖片進行記憶體快取 .cacheInMemory(true) //顯示圓形 .displayer(new CircleBitmapDisplayer()) .build(); ImageLoader.getInstance().displayImage(item.getPic_url(),image,options); } } }
4.工具類
package com.example.guoxinyu20181108;
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.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
public class NetUtil {
private static NetUtil instance;
//私有構造
public NetUtil() {
}
//定義方法獲取物件
public static NetUtil getInstance() {
if(instance == null){
instance = new NetUtil();
}
return instance;
}
//載入網路資料 返回string
public String getResult(String urlStr){
String result = null;
try {
//定義url地址
URL url = new URL(urlStr);
//開啟連線
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
//設定請求方式
urlConnection.setRequestMethod("GET");
//設定超時
urlConnection.setConnectTimeout(5000);
urlConnection.setReadTimeout(5000);
//獲取請求嗎
int responseCode = urlConnection.getResponseCode();
if(responseCode == 200){
result = stream2String(urlConnection.getInputStream());
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
//將位元組流轉換為字元流
private String stream2String(InputStream inputStream) throws IOException {
InputStreamReader isr = new InputStreamReader(inputStream);
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 getResult(String urlStr,Class clazz){
String result = getResult(urlStr);
E e = (E) new Gson().fromJson(result,clazz);
return e;
}
//定義一個介面
public interface CallBack<E>{
void onSuccess(E e);
}
//通過介面回撥
@SuppressLint("StaticFieldLeak")
public void getResult(String urlStr, final Class clazz, final CallBack callBack){
new AsyncTask<String,Void,Object>(){
@Override
protected Object doInBackground(String... strings) {
return getResult(strings[0],clazz);
}
@Override
protected void onPostExecute(Object o) {
callBack.onSuccess(o);
}
}.execute(urlStr);
}
}
5.Application頁面初始化imageloader
package com.example.guoxinyu20181108;
import android.app.Application;
import android.os.Environment;
import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiskCache;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import java.io.File;
public class App extends Application {
@Override
public void onCreate() {
String path = Environment.getExternalStorageDirectory()+ "/image";
File file = new File(path);
ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(this)
//配置記憶體快取
.memoryCacheSizePercentage(10)
//配置磁碟快取
.diskCache(new UnlimitedDiskCache(file))//UnlimitedDiskCache 限制這個圖片的快取路徑
.diskCacheFileCount(50)//配置sdcard快取檔案的數量
.diskCacheFileNameGenerator(new Md5FileNameGenerator())//MD5這種方式生成快取檔案的名字
.diskCacheSize(50 * 1024 * 1024)//在sdcard快取50MB
.build();
//初始化imageload
ImageLoader.getInstance().init(configuration);
super.onCreate();
}
}
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.guoxinyu20181108">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<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>