用ImageView展示数据,并使用handler每过3秒钟切换一张图片

添加的依赖:

implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'

------------------- MainActivity --------------------

package com.example.image;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;

import com.nostra13.universalimageloader.core.ImageLoader;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private List imgs;
    int time=3;
    private ImageView image;
    Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

            ImageLoader.getInstance().displayImage(imgs.get(time%imgs.size()),image);
            time++;
            sendEmptyMessageDelayed(1,3000);
        }
    };


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        image = (ImageView)findViewById(R.id.iv);


        imgs = new ArrayList<>();
        imgs.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1508910683617&di=73f055f2e18ad010b60f29bda13ca3a8&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fimage%2Fc0%253Dshijue1%252C0%252C0%252C294%252C40%2Fsign%3Da8e6763e61600c33e474d68b72253b7a%2F8644ebf81a4c510f1a7c57306a59252dd42aa564.jpg");
        imgs.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1508910757462&di=9e24a3cd1f6d00b3c373690b8b3ceb4e&imgtype=0&src=http%3A%2F%2Fpic.qiantucdn.com%2F58pic%2F19%2F75%2F71%2F571227cc578f2_1024.jpg");
        imgs.add("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1508910757460&di=461ac91bd572b862fff5c13a50b90f95&imgtype=0&src=http%3A%2F%2Fimgsrc.baidu.com%2Fimgad%2Fpic%2Fitem%2F5d6034a85edf8db1074e8e5d0223dd54564e74a3.jpg");

        handler.sendEmptyMessageDelayed(1,1000);
    }
}

 -------------------- MyApp -----------------------

package com.example.image;

import android.app.Application;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

/**
 * Created by Earl on 2017/10/26.
 */
public class Myapp extends Application {
    public void onCreate() {
        super.onCreate();
        ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(this).
                memoryCache(new LruMemoryCache(2 * 1024 * 1024))//设置内存缓存区大小
                .memoryCacheSize(2 * 1024 * 1024)//设置缓存区大小
                .memoryCacheExtraOptions(320, 320)//缓存图片最大的宽度与高度 px
                .diskCacheSize(50 * 1024 * 1024)//设置sd卡缓存的空间大小 
                .diskCacheFileNameGenerator(new Md5FileNameGenerator())//sd卡缓存图片的命名 使用md5加密方式
                .diskCacheFileCount(100)//缓存文件的最大数量
                .writeDebugLogs()//写入日志
                .build(); //对imageLoader进行初使化 ImageLoader.getInstance().init(configuration); 

    }
} 

 ---------------------- activity_main.xml ----------------------

   ---------------------------- AndroidManifest.xml -------------------------