handler刷新主界面

Android中主线程的职责是创建、显示和更新UI控件、处理UI事件、启动子线程、停止子线程。

子线程的职责是处理后台逻辑，向主线程发送UI更新。

实例化一个Handler对象，并重写handleMessage方法调用invalidate()实现界面刷新；而在线程中通过sendMessage发送界面更新消息。

 

       // 在onCreate()中开启线程

       new Thread(new GameThread()).start();、

 

       // 实例化一个handler

       Handler myHandler   = new Handler()

       {

              //接收到消息后处理

              public void handleMessage(Message msg)

              {

                     switch (msg.what)

                     {

                     case Activity01.REFRESH:

                            mGameView.invalidate();        //刷新界面

                            break;

                     }

                     super.handleMessage(msg);

              }                  

       };

 

       class GameThread implements Runnable

       {

              public void run()

              {

                     while (!Thread.currentThread().isInterrupted())

                     {

                            Message message = new Message();

                            message.what = Activity01.REFRESH;

                            //发送消息

                            Activity01.this.myHandler.sendMessage(message);

                            try

                            {

                                   Thread.sleep(100);

                            }

                            catch (InterruptedException e)

                            {

                                   Thread.currentThread().interrupt();

                            }

                     }

              }

       }