异步加载图片--狸菇凉_

简单的异步加载图片只需要两个类就可以，一个mainactivity类，一个自己建的ImageloaderAsyncTask类。

ImageLoadAsyncTask类

public class ImageLoadAsyncTask extends AsyncTask<String,Void,Bitmap>{

 

    /**

     * 定义一个图片的接口回调

     */

    public interface ImageCallBack{

        void callBitmap(Bitmap bitmap);

    }

 

    //定义变量记住调用者所传递进来的回调监听对象

    private ImageCallBack imageCallBack;

    //构造方法

    public ImageLoadAsyncTask(ImageCallBack imageCallBack){

        this.imageCallBack = imageCallBack;

 

    }

 

    @Override

    protected void onPostExecute(Bitmap bitmap) {

        super.onPostExecute(bitmap);

 

        if(bitmap != null){

            //设置图片 回调回去

            imageCallBack.callBitmap(bitmap);

        }

 

 

    }

 

    @Override

    protected Bitmap doInBackground(String... params) {

 

        try {

            String path = params[0];

            URL url = new URL(path);

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();

            connection.setRequestMethod("GET");

            connection.setConnectTimeout(5*1000);

            connection.setReadTimeout(5*1000);

            //服务器响应

            int code = connection.getResponseCode();

            if(code == HttpURLConnection.HTTP_OK){//判断服务器是否连接成功并相应

                //图片流

                InputStream is = connection.getInputStream();

                //将图片流转化成Bitmap位图，返回

                return BitmapFactory.decodeStream(is);

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        return null;

    }

Mainactivity类

private ImageView ivIcon;

 

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

 

        ivIcon = (ImageView) findViewById(R.id.ivIcon);

 

 

    }

 

    public  void btnLoadImage(View v){

 

        loadImg("http://20.1.3.46:8080/tomcat.png");

 

    }

 

    /**

     * 加载图片

     * @param url  图片地址

     */

    private void loadImg(String url){

 

 

        ImageLoadAsyncTask imageLoadAsyncTask = new ImageLoadAsyncTask(new ImageLoadAsyncTask.ImageCallBack() {

            @Override

            public void callBitmap(Bitmap bitmap) {

 

                if(bitmap != null){

                    ivIcon.setImageBitmap(bitmap);

                }

 

            }

        });

        //执行图片请求

        imageLoadAsyncTask.execute(url);

 

 

    }

这就可以加载出来特别简单的图片了。