Handelr（二上）-- MarsChen Android 开发教程学习笔记

在XML 文件中的代码：

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.shumin.lbs08.MainActivity" >

    <TextView 
        android:id="@+id/textview"
        android:layout_height="25dp"
        android:layout_width="match_parent"
        android:text="还没接受信息。"/>
    
    <Button 
        android:id="@+id/button"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:layout_below="@id/textview"
        android:text="BUTTON"/>
    
    

</RelativeLayout>

在JAVA 文件中的代码：

package com.shumin.lbs08;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
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.TextView;


public class MainActivity extends ActionBarActivity {

private Button button;
private Handler handler;
private TextView textview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textview=(TextView)findViewById(R.id.textview);
        button=(Button)findViewById(R.id.button);
        ButtonListener listener=new ButtonListener();
        button.setOnClickListener(listener);
        handler=new MyHandler();
    }

    
    class ButtonListener implements OnClickListener{

@Override
public void onClick(View v) {
Thread t=new NetworkeThread();
t.start();
}
    
    }
    class NetworkeThread extends Thread{
    public void run(){
    try{
    Thread.sleep(5000);
    }catch(InterruptedException e){
    e.printStackTrace();
    }
    String s="接收到了数据！";
    Message msg=handler.obtainMessage();
    msg.obj=s;
    handler.sendMessage(msg);
    }
    
    }
    class MyHandler extends Handler{

@Override
public void handleMessage(Message msg) {
String s=(String)msg.obj;
textview.setText(s);
}
    
    }
    
    
    @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);
    }
}