Android--多线程之进程与线程

package com.example.workthreaddemo;

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.os.Bundle;
import android.os.Message;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v4.widget.SimpleCursorAdapter.ViewBinder;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class MainActivity extends Activity {
private Button  btnError2,btnRunOnUiThread,btnPost;
private ImageView imageView1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

imageView1=(ImageView)findViewById(R.id.imageView1);
btnRunOnUiThread = (Button) findViewById(R.id.btnRunOnUiThread);
btnError2 = (Button) findViewById(R.id.btnError2);
btnPost = (Button) findViewById(R.id.btnPost);

btnError2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 增加一个线程访问网络
new Thread(new Runnable() {
@Override
public void run() {
// 获取地址下的图片
Bitmap btm=loadImageFromNetwork("http://ww4.sinaimg.cn/bmiddle/786013a5jw1e7akotp4bcj20c80i3aao.jpg");
imageView1.setImageBitmap(btm);
}
}).start();

}
});

btnRunOnUiThread.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
new Thread(new Runnable() {

@Override
public void run() {
final Bitmap btm=loadImageFromNetwork("http://ww4.sinaimg.cn/bmiddle/786013a5jw1e7akotp4bcj20c80i3aao.jpg");
MainActivity.this.runOnUiThread(new Runnable() {
@Override
public void run() {
imageView1.setImageBitmap(btm);
}
});
}
}).start();
}
});

btnPost.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
new Thread(new Runnable() {

@Override
public void run() {
final Bitmap btm=loadImageFromNetwork("http://ww1.sinaimg.cn/bmiddle/88ff29e8jw1e7pjnpfxbrj20dp0a90tb.jpg");
imageView1.post(new Runnable() {

@Override
public void run() {
// TODO Auto-generated method stub
imageView1.setImageBitmap(btm);
}
});
}
}).start();

}
});
}

@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;
}

private Bitmap loadImageFromNetwork(String uri)
{
Bitmap bitmap=null;
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(uri);
HttpResponse httpResponse = null;
try {
httpResponse = httpClient.execute(httpGet);
if (httpResponse.getStatusLine().getStatusCode() == 200) {
byte[] data = EntityUtils.toByteArray(httpResponse
.getEntity());
bitmap=BitmapFactory.decodeByteArray(data, 0, data.length);

}
} catch (Exception e) {
e.printStackTrace();
}
return bitmap;
}

}