使用AsyncTask 自定义加载图片（接口回调）

来源：互联网发布：深圳市网络诈骗编辑：程序博客网时间：2024/06/03 21:26
package com.example.viewpagerbanner.utils;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.os.AsyncTask;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;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;    }}//Activity 中调用public class MainActivity extends AppCompatActivity {    private ImageView imageView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        imageView = (ImageView) findViewById(R.id.image);    getasynctask("http://img.juhe.cn/cookbook/s/1/45_b6d7329b703f6e85.jpg");    }    public void getasynctask(String url){        LoadAsynctask loadAsynctask=new LoadAsynctask(new LoadAsynctask.Loadimage() {            @Override            public void image(Bitmap bitmap) {                imageView.setImageBitmap(bitmap);            }        });        loadAsynctask.execute(url);    }}
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