package com.example.asynctask;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
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.support.v7.app.ActionBarActivity;
import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
private Button button;
private ImageView imageView;
private final String IMAGE_PATH = "http://www.baidu.com/img/bdlogo.gif";
private ProgressDialog dialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)this.findViewById(R.id.button1);
imageView = (ImageView)this.findViewById(R.id.imageView1);
dialog = new ProgressDialog(this);
dialog.setTitle("提示");
dialog.setMessage("请耐心等候......");
dialog.setCancelable(false);
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
new MyTask().execute(IMAGE_PATH);
}
});
}
public class MyTask extends AsyncTask<String, Integer, byte[]>{
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
dialog.show();
}
@Override
protected byte[] doInBackground(String... params) {
// TODO Auto-generated method stub
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(params[0]);
byte[] result =null;
InputStream inputStream = null;
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try{
HttpResponse httpResponse = httpClient.execute(httpGet);
long file_length = httpResponse.getEntity().getContentLength();
int total_length = 0;
byte[] data = new byte[1024];
int len = 0;
if(httpResponse.getStatusLine().getStatusCode()==200){
//result = EntityUtils.toByteArray(httpResponse.getEntity());
inputStream = httpResponse.getEntity().getContent();
while((len=inputStream.read(data))!=-1){
total_length +=len;
int progress_value = (int)((total_length/(float)file_length)*100);
publishProgress(progress_value);
outputStream.write(data,0,len);
}
}
result = outputStream.toByteArray();
}catch (Exception e){
e.printStackTrace();
} finally{
httpClient.getConnectionManager().shutdown();
}
return result;
}
@Override
protected void onProgressUpdate(Integer... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
dialog.setProgress(values[0]);
}
@Override
protected void onPostExecute(byte[] result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
Bitmap bitmap = BitmapFactory.decodeByteArray(result, 0, result.length);
imageView.setImageBitmap(bitmap);
dialog.dismiss();
}
}
@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);
}
}