imageloder使用

本文主要是介绍imageloder使用，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

//工具类

package com.example.imageloader;import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.Log;
import android.util.LruCache;
import android.widget.ImageView;import com.google.gson.Gson;import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;public class NetUtil {//单例private static NetUtil instance;//私有构造方法private NetUtil() {}//提供方法,获取对象public static NetUtil getInstance() {if(instance == null) {instance = new NetUtil();}return instance;}///普通get请求public interface Callbak<T>{void onSuccess(T t);}///执行一个网络请求,通过回调返回结果public void getRequest(final String urlStr, final Class clazz, final Callbak callbak) {new AsyncTask<String, Void, Object>(){@Overrideprotected Object doInBackground(String... strings) {return getRequest(urlStr, clazz);}@Overrideprotected void onPostExecute(Object o) {callbak.onSuccess(o);}}.execute(urlStr);}//执行一个网络请求,返回beanpublic <T> T getRequest(String urlStr, Class clazz) {return (T) new Gson().fromJson(getRequest(urlStr), clazz);}//执行一个网络请求,返回String结果public String getRequest(String urlStr) {String result = "";try {URL url = new URL(urlStr);HttpURLConnection 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;}private String stream2String(InputStream is) throws IOException {StringBuilder sb = new StringBuilder();BufferedReader br = new BufferedReader(new InputStreamReader(is));for (String tmp = br.readLine(); tmp != null; tmp = br.readLine()) {sb.append(tmp);}return sb.toString();}
}

//listview适配器

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();
}@Overridepublic int getCount() {return mlist.size();}@Overridepublic Bean.DataBean getItem(int position) {return mlist.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic 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   *   每个像素占用字节数16////RGB_565       red green blue     红绿蓝 的颜色      r占5byte   g占6byte    b占5byte//A RGB_4444 A RGB_8888//ALPHA_8//BitmapDisplayerDisplayImageOptions options = new DisplayImageOptions.Builder()//配置色彩模式.bitmapConfig(Bitmap.Config.RGB_565)//配置  是否缓存.cacheInMemory(true).cacheOnDisk(true)//配置 默认显示.showImageOnLoading(R.mipmap.ic_launcher).showImageOnFail(R.mipmap.ic_launcher).showImageForEmptyUri(R.mipmap.ic_launcher)//配置图片如何缩放.imageScaleType(ImageScaleType.EXACTLY)//显示效果:圆形//.displayer(new CircleBitmapDisplayer())//圆角//.displayer(new RoundedBitmapDisplayer(8)).displayer(new FadeInBitmapDisplayer(2000)).build();//加载图片ImageLoader.getInstance().displayImage(getItem(position).getPic_url(), viewHoder.imageView, options);//只加载图片//回调返回bitmap//ImageLoader.getInstance().loadImage();return convertView;}class ViewHoder{private TextView textView1,textView2;private ImageView imageView;}
}

//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;@Overrideprotected 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() {@Overridepublic void onClick(View v) {//加载数据NetUtil.getInstance().getRequest("http://api.expoon.com/AppNews/getNewsList/type/1/p/1", Bean.class, new NetUtil.Callbak<Bean>() {@Overridepublic void onSuccess(Bean o) {mAdapter.setListData(o.getData());}});}});}
}

继承AppCompatActivity,初始化imageloder

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;//优先于所有页面(Activity)创建
//主要负责应用全局初始化
//该对象也是一个context
public class App extends Application {@Overridepublic void onCreate() {super.onCreate();//ctrl + h 查看累的继承结构//MemoryCache//DiskCache//FileNameGenerator//怎么调用api//要什么参数//怎么给这个参数//Builder//构建模式//链式调用//全局配置ImageLoaderConfiguration configuration = null;DisplayImageOptions options = new DisplayImageOptions.Builder().build();//try {//configuration = new ImageLoaderConfiguration.Builder(this)//配置:内存 磁盘 缓存//.memoryCache(new LruMemoryCache())//.memoryCacheSize()//内存缓存大小.memoryCacheSizePercentage(10)//配置磁盘缓存:目录 文件名生成  大小//.diskCache(new LruDiskCache(getCacheDir(), new HashCodeFileNameGenerator(), 10*1024*1024)).diskCacheSize(50*1024*1024)//线程配置//任务优先级配置//FIFO//加载图片1   2  3  4  5//LIFO//.tasksProcessingOrder(QueueProcessingType.)//默认显示配置//.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);//无效果//ImageLoader.getInstance().init(null);/* ImageLoader.getInstance().init(new ImageLoaderConfiguration.Builder(this).diskCacheSize(50 * 1024 * 1024).memoryCacheSizePercentage(10).defaultDisplayImageOptions(new DisplayImageOptions.Builder().cacheInMemory(true).cacheOnDisk(true).showImageOnLoading(R.mipmap.ic_launcher).showImageOnFail(R.mipmap.ic_launcher).showImageForEmptyUri(R.mipmap.ic_launcher).build()).build()*/}
}

这篇关于imageloder使用的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

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