android 学习笔记4——post请求+线程控制

由于网络访问需要时间，故放入子线程，并通过handler在UI线程（主线程）中进行显示的更新：

MainActivity.java:

package com.example.isns;import android.app.Activity;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.text.Html;import android.text.method.ScrollingMovementMethod;import android.widget.TextView;import java.io.IOException;import java.util.ArrayList;import java.util.List;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;import org.apache.http.protocol.HTTP;import org.apache.http.util.EntityUtils;public class MainActivity extends Activity {private static final int MSG_SUCCESS = 0;private static final int MSG_FAILURE = 1;private TextView t;private String result;private Handler handler = new Handler(){public void handleMessage(Message msg){switch(msg.what){case MSG_SUCCESS:t.setMovementMethod(ScrollingMovementMethod.getInstance());t.setText(Html.fromHtml(result));break;case MSG_FAILURE:t.setText("fail");break;}}};    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        t = (TextView)findViewById(R.id.tv);    Post();    }    private void Post(){    new Thread(){    public void run(){    String url = "http://www.w3school.com.cn/example/php/demo_php_global_post.php";        HttpPost httpPost = new HttpPost(url);        List<NameValuePair> params = new ArrayList<NameValuePair>();        params.add(new BasicNameValuePair("fname","ISNS"));        HttpResponse httpResponse = null;        try{        httpPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));        httpResponse = new DefaultHttpClient().execute(httpPost);        if(httpResponse.getStatusLine().getStatusCode() == 200){        result = EntityUtils.toString(httpResponse.getEntity());        handler.obtainMessage(MSG_SUCCESS).sendToTarget();        }        }catch(ClientProtocolException e){        e.printStackTrace();        }catch(IOException e){        e.printStackTrace();        }    }    }.start();    }}

activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="${relativePackage}.${activityClass}" >    <TextView        android:id="@+id/tv"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="@string/hello_world" /></RelativeLayout>

要记得在manifest中加入网络访问权限：

<uses-permission           android:name="android.permission.INTERNET"/>

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