AsyncTask的代码

package com.example.asynctask1409g;

import com.example.asynctask1409g.net.HttpUtils;

import android.app.Activity;

import android.app.ProgressDialog;

import android.graphics.Bitmap;

import android.os.AsyncTask;

import android.os.Bundle;

import android.widget.ImageView;

public class MainActivity extends Activity {

private ImageView mIv;

private ProgressDialog mDlg;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initViews();

//图片地址

String url = "http://101.200.142.201:8080/tqyb/images/top1.png";

new AsyncTask<String, Void, Bitmap>() {

@Override

protected Bitmap doInBackground(String... params) {

//后台耗时操作

Bitmap bm = null;

try {

//休眠３秒

Thread.sleep(3000);

bm = HttpUtils.readImage(params[0]);

} catch (Exception e) {

e.printStackTrace();

}

return bm;

}

protected void onPostExecute(Bitmap result) {

//更新ＵＩ

mIv.setImageBitmap(result);

//关闭加载框

mDlg.dismiss();

};

protected void onPreExecute() {

//请求前

mDlg = ProgressDialog.show(MainActivity.this, "提示", "加载中...");

};

}.execute(url);

}

private void initViews() {

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

}

}