一:
在android中有两种实现线程thread的方法:
一种是,扩展java.lang.Thread类
另一种是,实现Runnable接口
二:
Thread类代表线程类,它的两个最主要的方法是:
run()——包含线程运行时所执行的代码
Start()——用于启动线程
三:
Handler 机制,它是Runnable和Activity交互的桥梁,在run方法中发送Message,在Handler里,通过不同的Message执行不同的任务。
下面分别给出两种线程的实现方法,其一,扩展java.lang.Thread类,也就是把run()方法写到线程里面:
package com.my;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class Demo_For_Copy extends Activity
{
public Button button;
public Handler mHandler=new Handler()
{
public void handleMessage(Message msg)
{
switch(msg.what)
{
case 1:
button.setText(R.string.text2);
break;
default:
break;
}
super.handleMessage(msg);
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button=(Button)findViewById(R.id.button);
Thread thread=new Thread(new Runnable()
{
@Override
public void run()
{
Log.e("1111", "111111111");
// TODO Auto-generated method stub
Message message=new Message();
message.what=1;
mHandler.sendMessage(message);
}
});
thread.start();
}
}
其二,实现Runnable接口,让类实现Runnable接口,然后把run方法单独提出来:
package com.my;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
public class Title_Change_Demo extends Activity implements Runnable
{
public Button button;
public LinearLayout my_layout;
public Handler mHandler=new Handler()
{
public void handleMessage(Message msg)
{
switch(msg.what)
{
case 1:
button.setText(R.string.text2);
break;
default:
break;
}
my_layout.invalidate();
super.handleMessage(msg);
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button=(Button)findViewById(R.id.button);
my_layout=(LinearLayout)findViewById(R.id.my_layout);
Thread thread=new Thread(this);
thread.start();
}
@Override
public void run()
{
Log.e("ok", "111111111");
// TODO Auto-generated method stub
Message message=new Message();
message.what=1;
mHandler.sendMessage(message);
}
}