Android测试AsyncTask下载图片

时间:2023-03-08 19:41:42
 package com.example.myact8_async;

 import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
/**
* 测试AsyncTask异步任务进行下载图片
* @Describe:
* @package: com.example.myact8_async
* @author shaobn
* @date 2015-9-11 下午4:03:24
*/
public class MainActivity extends ActionBarActivity {
private Button button;
private ImageView iv;
private ProgressDialog pd;
private final static String URLPATH = "http://d.hiphotos.baidu.com/image/pic/item/f3d3572c11dfa9ec919c6f1960d0f703918fc109.jpg";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv = (ImageView) this.findViewById(R.id.imageView1);
pd = new ProgressDialog(this);
pd.setTitle("下载提示");
pd.setMessage("正在下载,请稍后...");
button = (Button) this.findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() { @Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
new MyAsync().execute(MainActivity.URLPATH);
}
});
}
/**
* 自定义异步任务类
* @Describe:
* @package: com.example.myact8_async
* @author shaobn
* @date 2015-9-11 下午4:27:09
*/
public class MyAsync extends AsyncTask<String, Void, Bitmap>{
//下载进程
@Override
protected Bitmap doInBackground(String... arg0) {
// TODO Auto-generated method stub
HttpClient hClient = new DefaultHttpClient();
HttpGet hGet = new HttpGet(MainActivity.URLPATH);
Bitmap bitmap = null;
try {
//实现图片下载
HttpResponse hResponse = hClient.execute(hGet);
if(hResponse.getStatusLine().getStatusCode()==200){
HttpEntity hEntity = hResponse.getEntity();
byte[] byt = EntityUtils.toByteArray(hEntity);
bitmap = BitmapFactory.decodeByteArray(byt, 0, byt.length);
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return bitmap; }
//下载后执行操作
@Override
protected void onPostExecute(Bitmap result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
MainActivity.this.iv.setImageBitmap(result);
MainActivity.this.pd.dismiss();
}
//下载前动作
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
MainActivity.this.pd.show();
} } @Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
} @Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}

自己写的小程序,方便保存一下。