private volatile boolean mStopped = false; private int i; TextView tv1; TextView tv2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main3); tv1 = (TextView) findViewById(R.id.tv1); tv2 = (TextView) findViewById(R.id.tv2); Button button4 = (Button) findViewById(R.id.button4); //获取“开始”按钮 Button button5 = (Button) findViewById(R.id.button5); //获取“停止”按钮 //开始按钮 button4.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if( mStopped = true) { mStopped = false; Log.i("主线程ID", String.valueOf(Thread.currentThread().getId())); Log.i("主线程var", String.valueOf(Thread.currentThread().getName())); fgetsum(String.valueOf("mytv1"), 1); fgetsum(String.valueOf("mytv2"), 2); } } }); //结束线程按钮 button5.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mStopped = true; } }); } //定义Handler 消息处理类,Handler 允许发送和处理 Message 或 Rannable 对像到其所在线程的 MessageQueue中 //Handler接收Message通知,并刷新tv1 //一般在这里刷新UI final Handler handler2 = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what){ case 0x101: tv1.setText(String.valueOf(msg.obj.toString())); break; case 0x102: tv2.setText(String.valueOf(msg.obj.toString())); break; default: tv1.setText(String.valueOf("未知msg.what")); break; } } }; //定义Runnable接口 //在子线程中发送Message给Handler //Runnable不会在UI运行,所以在这里不能直接修改UI对象属性 private void fgetsum(final String strname, final int tvid) { Thread thread = new Thread() { @Override public void run() { while (mStopped == false) { i++; try { Thread.sleep(1000); Log.i("子线程ID" + strname, String.valueOf(Thread.currentThread().getId())); Log.i("子线程名" + strname, String.valueOf(Thread.currentThread().getName())); Message message = handler2.obtainMessage(); message.arg1 = tvid; //如果tvid=1传入时间,否则传入i if(tvid==1){ SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss", Locale.getDefault()); message.what=0x101; message.obj = String.valueOf(sdf.format(new Date())); }else{ message.what=0x102; message.obj =i; } handler2.sendMessage(message); } catch (InterruptedException e) { e.printStackTrace(); } } } }; thread.start(); thread = null; }
Android 跟winform一样,,主线程上不能直接更新UI上的控件,否则界面会假死(比如进度条、下载等任务)
在ASP.NET下有BackgroundWorker,而Android一般用Handler+Thread+Message来实现,对于用惯了.net的人说,看JAVA程序会很不习惯,很多功能实现起来比.NET麻烦多了。。。。。
另外查了一下JAVA资料,如果要创建N个线程,建议用线程序池(ExecutorService)更好.