ImageLoader載入圖片

1主佈局

<android.support.constraint.ConstraintLayout xmlns:android=“http://schemas.android.com/apk/res/android”
xmlns:app=“http://schemas.android.com/apk/res-auto”
xmlns:tools=“http://schemas.android.com/tools”
android:layout_width=“match_parent”
android:layout_height=“match_parent”
tools:context=".MainActivity">

<Button
    android:id="@+id/left"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="url con"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toLeftOf="@id/right"/>

<Button
    android:id="@+id/right"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="client"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintLeft_toRightOf="@id/left"/>

<ListView
    android:id="@+id/news"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@id/left"
    app:layout_constraintBottom_toBottomOf="parent"/>

</android.support.constraint.ConstraintLayout>
 

2 、 listview子佈局

<android.support.constraint.ConstraintLayout xmlns:android=“http://schemas.android.com/apk/res/android”
android:layout_width=“match_parent”
android:layout_height=“wrap_content”
xmlns:app=“http://schemas.android.com/apk/res-auto”>

<ImageView
    android:id="@+id/imageview"
    android:layout_width="140dp"
    android:layout_height="100dp"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"/>

<TextView
    android:id="@+id/textview1"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    app:layout_constraintTop_toTopOf="@id/imageview"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toLeftOf="@id/imageview"/>

<TextView
    android:id="@+id/textview2"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="@id/imageview"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toLeftOf="@id/imageview"/>

</android.support.constraint.ConstraintLayout>
 

3//MainActivity主函式

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());
                }
            });
        }
    });
}
}

4Bean類

package com.example.imageloader;

import java.util.List;

public class Bean {

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_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;
    }
}
}

5 adapter介面卡

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;
}
}

6工具類**

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 {
  
//單例
private static NetUtil instance;

//私有構造方法
private NetUtil() {
}

//提供方法,獲取物件
public static NetUtil getInstance() {
    if(instance == null) {
        instance = new NetUtil();
    }
    return instance;
}

///////////////////普通get請求

public interface Callbak<T>{
    void onSuccess(T t);
}

///執行一個網路請求,通過回撥返回結果
public void getRequest(final String urlStr, final Class clazz, final Callbak callbak) {
    new AsyncTask<String, Void, Object>(){
        @Override
        protected Object doInBackground(String... strings) {
            return getRequest(urlStr, clazz);
        }

        @Override
        protected void onPostExecute(Object o) {
            callbak.onSuccess(o);
        }
    }.execute(urlStr);
}


//執行一個網路請求,返回bean
public <T> T getRequest(String urlStr, Class clazz) {
    return (T) new Gson().fromJson(getRequest(urlStr), clazz);
}

//執行一個網路請求,返回String結果
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();
}
}

初始化介面
//此頁面初始化所有頁面中載入圖片的的格式但是要註冊

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);
}
}

在androidMainfest中註冊

<?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"
    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>

APP全域性配置

@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);
}