Question

我正在编写一个Android应用程序，我需要设置一个Timer，每隔一秒执行一次方法，然后一旦布尔变量（由前面提到的方法设置）变为真，就停止。

以下是我正在尝试做的事情的概述：

boolean done = false;    

public void someMethod() {
    if(done == false) {
       myTimer = new Timer(); //Set up a timer, to execute TimerMethod repeatedly
       myTimer.schedule(new TimerTask() {
            @Override
            public void run() {
               TimerMethod();
            }
        }, 0, 1000);
    }

    if(done == true) { 
        //TimerMethod will eventually set 'done' to true. When this happen, do layout modifying stuff here. Causes error as non-UI thread is executing the layout modifying stuff. Do I spawn a new UI thread here to do it? If so, how? :/
    }
}

TimerMethod() {
   String result = someServerMethod();
   if(result == "theResultWeWant") {
         myTimer.cancel(); //stop the timer - we're done!
         done = true; //set 'done' to true so the line of code in someMethod() will now run
         someMethod();
   }
}

编辑：我已更新上面的代码以反映我想要做的事情。我希望我可以将完成的flash设置为true，然后继续执行someMethod，但我确定它不是那么简单！我是否需要从TimerMethod（）生成一个新线程来执行done == true行的代码？

Answer 1

所有UI交互都需要从主（UI）线程完成。在你的情况下，你从TimerTask调用someMethod（），这是一个单独的线程。处理程序用于与辅助线程中的主线程交互。

    public void someMethod() {

          myTimer = new Timer(); //Set up a timer, to execute TimerMethod repeatedly
          myTimer.schedule(new TimerTask() {
               @Override
               public void run() {
                  TimerMethod();
               }
           }, 0, 1000);
       }

    }

    TimerMethod() {
       String result = someServerMethod();
       if(result.equals("theResultWeWant")) {
             myTimer.cancel(); //stop the timer - we're done!
             mHandler.sendEmptyMessage(0): //send message to handler to update UI
       }
    }

private Handler mHandler = new Handler(){
    public void handleMessage(Message msg) {
        doUIMethod();
    }

};

Android计时器线程以“真实”状态退出

1 个答案: