这篇文章中有三点需要提前说明一下,
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:
代码如下 | 复制代码 |
packagecom.my; importandroid.app.Activity; importandroid.os.Bundle; importandroid.os.Handler; importandroid.os.Message; importandroid.util.Log; importandroid.view.View; importandroid.view.View.OnClickListener; importandroid.widget.Button; publicclassDemo_For_CopyextendsActivity { publicButton button;
publicHandler mHandler=newHandler() { publicvoidhandleMessage(Message msg) { switch(msg.what) { case1: button.setText(R.string.text2); break; default: break; } super.handleMessage(msg); } };
/** Called when the activity is first created. */ @Override publicvoidonCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); button=(Button)findViewById(R.id.button);
Thread thread=newThread(newRunnable() { @Override publicvoidrun() { Log.e("1111","111111111"); // TODO Auto-generated method stub Message message=newMessage(); 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:
代码如下 | 复制代码 |
packagecom.my; importandroid.app.Activity; importandroid.os.Bundle; importandroid.os.Handler; importandroid.os.Message; importandroid.util.Log; importandroid.view.View; importandroid.view.View.OnClickListener; importandroid.widget.Button; importandroid.widget.LinearLayout; publicclassTitle_Change_DemoextendsActivityimplementsRunnable { publicButton button; publicLinearLayout my_layout;
publicHandler mHandler=newHandler() { publicvoidhandleMessage(Message msg) { switch(msg.what) { case1: button.setText(R.string.text2); break; default: break; } my_layout.invalidate(); super.handleMessage(msg); } };
/** Called when the activity is first created. */ @Override publicvoidonCreate(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=newThread(this); thread.start(); }
@Override publicvoidrun() { Log.e("ok","111111111"); // TODO Auto-generated method stub Message message=newMessage(); message.what=1; mHandler.sendMessage(message); } } |