android 多线程2：thread

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前面已经介绍了AsyncTask，现在介绍Thread。

继承Thread捕捉run()异常避免因为线程中出现异常导致程序崩溃

/**安全线程抽象类 * Description:安全线程抽象类，此线程类已经封闭run函数，添加抽象函数runs，后者只需将业务代码放入runs中即可，可有效防止在线程中出现未捕获的异常而导致程序崩溃 * @author 爱吃鱼的cat * @date 2013-1-18 */public abstract class Thread extends java.lang.Thread{/** * 线程 实际执行函数，已被封闭，请实现runs方法将业务处理相关动作放在里面 */@Overridepublic final void run(){try{runs();} catch (Exception e){Log.e("Thread","-----------------线程执行出现未捕获异常------------------");e.printStackTrace();}}/** * 线程执行函数，里面执行业务代码 */public abstract void runs();}

使用Thread创建子线程与界面交互有两种方式第一种使用runOnUiThread

new Thread(){@Overridepublic void runs(){DisplayMetrics dm = new DisplayMetrics();context.getWindowManager().getDefaultDisplay().getMetrics(dm); String strOpt = "手机屏幕分辨率为：" + dm.widthPixels + " × " + dm.heightPixels; runOnUiThread(new Runnable(){public void run(){mTextView.setText((String)extra);}});}}.start();

第二种方式是使用Handle,Handler来根据接收的消息，处理UI更新。Thread线程发出Handler消息，通知更新UI。

@SuppressLint("ValidFragment")public static class PlaceholderFragment extends Fragment{private TextView mTextView;private Button mbtnGet;private MainActivity context;Handler myHandler = new Handler(){public void handleMessage(Message msg){switch (msg.what){case 0x01:mTextView.setText((String) msg.obj);break;}super.handleMessage(msg);}};public PlaceholderFragment()         {super();}public PlaceholderFragment(MainActivity context){this.context = context;}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState){View rootView = inflater.inflate(R.layout.fragment_main, container,false); mbtnGet = (Button)rootView.findViewById(R.id.myButton) mTextView = (TextView) rootView.findViewById(R.id.myTextView);  mbtnGet.setOnClickListener(new View.OnClickListener(){@Overridepublic void onClick(View v){new Thread(){@Overridepublic void runs(){DisplayMetrics dm = new DisplayMetrics();context.getWindowManager().getDefaultDisplay().getMetrics(dm); String strOpt = "手机屏幕分辨率为：" + dm.widthPixels + " × " +dm.heightPixels; Message message = new Message(); message.what = 0x01;message.obj = strOpt;myHandler.sendMessage(message); }}.start();}}); return rootView;}}

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