Android多线程——Handler(一)实现图片下载-创新互联
在UI线程中创建子线程——》在子线程中获取网络图片--》在线程中通过Message 传递二进制图片给Handler,--》Handler在handleMessage()中处理消息

package com.example.android_handler_message;
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
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.Handler;
import android.os.Message;
import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
private static int IS_FINISHED = 1;
private Button button = null;
private ImageView p_w_picpathView = null;
private String p_w_picpath_path = "http://i1.juyouqu.com/uploads/content//2014/04/1396611698344.jpg!w598";
private ProgressDialog dialog = null;
private Handler handle = new Handler(){
public void handleMessage(android.os.Message msg)
{
Bitmap bitmap = null;
byte[] data = (byte[])msg.obj;
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
if(msg.what == IS_FINISHED)
{
dialog.dismiss();
p_w_picpathView.setImageBitmap(bitmap);
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)findViewById(R.id.button1);
p_w_picpathView = (ImageView)findViewById(R.id.p_w_picpathView1);
dialog = new ProgressDialog(this);
dialog.setTitle("提示");
dialog.setMessage("正在下载..........");
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
new Thread(new MyTask()).start();
dialog.show();
}
});
}
public class MyTask implements Runnable
{
@Override
public void run() {
// TODO Auto-generated method stub
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(p_w_picpath_path);
try {
HttpResponse httpResponse = httpClient.execute(httpGet);
if(httpResponse.getStatusLine().getStatusCode() == 200)
{
byte[] data = EntityUtils.toByteArray(httpResponse.getEntity());
Message message = Message.obtain();
message.obj = data;
message.what = IS_FINISHED;
handle.sendMessage(message);
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}另外有需要云服务器可以了解下创新互联scvps.cn,海内外云服务器15元起步,三天无理由+7*72小时售后在线,公司持有idc许可证,提供“云服务器、裸金属服务器、高防服务器、香港服务器、美国服务器、虚拟主机、免备案服务器”等云主机租用服务以及企业上云的综合解决方案,具有“安全稳定、简单易用、服务可用性高、性价比高”等特点与优势,专为企业上云打造定制,能够满足用户丰富、多元化的应用场景需求。
标题名称:Android多线程——Handler(一)实现图片下载-创新互联
链接分享:http://www.scyingshan.cn/article/cophdg.html


咨询
建站咨询
