一、新建PictureLoader public class PictureLoader {private ImageView loadImg;private String imgUrl;private byte[] picByte;Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {super.handleMessage(msg);if (msg.what == 0x123) {if (picByte != null) {Bitmap bitmap = BitmapFactory.decodeByteArray(picByte, 0, picByte.length);loadImg.setImageBitmap(bitmap);}}}};public void load(ImageView loadImg, String imgUrl) {this.loadImg = loadImg;this.imgUrl = imgUrl;Drawable drawable = loadImg.getDrawable();if(drawable != null && drawable instanceof BitmapDrawable) {Bitmap bitmap = ((BitmapDrawable)drawable).getBitmap();if(bitmap != null && !bitmap.isRecycled()) {bitmap.recycle();}}new Thread(runnable).start();}Runnable runnable = new Runnable() {@Overridepublic void run() {try {URL url = new URL(imgUrl);HttpURLConnection conn = (HttpURLConnection) url.openConnection();conn.setRequestMethod("GET");conn.setReadTimeout(10000);if (conn.getResponseCode() == 200) {InputStream in = conn.getInputStream();ByteArrayOutputStream out = new ByteArrayOutputStream();byte[] bytes = new byte[1024];int length = -1;while ((length = in.read(bytes)) != -1) {out.write(bytes, 0, length);}picByte = out.toByteArray();in.close();out.close();handler.sendEmptyMessage(0x123);}} catch (IOException e) {e.printStackTrace();}}};}

  二、新建Activity界面

public class MainActivity extends AppCompatActivity implements View.OnClickListener {private Button showBtn;private ImageView showImg;private ArrayList<String> urls;private  int curPos=0;private PictureLoader loader;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);showBtn=(Button)findViewById(R.id.showBtn);showImg=(ImageView)findViewById(R.id.img_show);loader=new PictureLoader();showBtn.setOnClickListener(this);urls=new ArrayList<>();urls.add("https://img1.baidu.com/it/u=2613963793,934854936&fm=253&fmt=auto&app=120&f=JPEG?w=1280&h=800");urls.add("https://img2.baidu.com/it/u=2453741982,2770329727&fm=253&fmt=auto&app=120&f=JPEG?w=1280&h=800");urls.add("https://img0.baidu.com/it/u=494561658,4056512075&fm=253&fmt=auto&app=138&f=JPEG?w=800&h=500");urls.add("https://img2.baidu.com/it/u=2389087729,70628867&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=750");urls.add("https://k.sinaimg.cn/n/sinakd10100/50/w660h990/20240323/d50c-5faa98beb0d96d35c6ae9444d98b3c0d.jpg/w700d1q75cms.jpg");urls.add("https://img0.baidu.com/it/u=2673688411,90488494&fm=253&fmt=auto&app=138&f=JPEG?w=480&h=800");urls.add(" https://img1.baidu.com/it/u=1682400140,1262357671&fm=253&fmt=auto&app=138&f=JPEG?w=500&h=500");urls.add("https://img1.baidu.com/it/u=2064828371,3291434219&fm=253&fmt=auto&app=138&f=JPEG?w=360&h=360");urls.add("https://img2.baidu.com/it/u=2148980033,2323997411&fm=253&fmt=auto&app=138&f=JPEG?w=759&h=500");}@Overridepublic void onClick(View v) {switch (v.getId()){case R.id.showBtn:if(curPos>9){curPos=0;}Logger.d(urls.get(curPos));loader.load(showImg,urls.get(curPos));curPos++;break;}}
}