如何在java fx中每2秒更新一次标签框？ [英] How to update the label box every 2 seconds in java fx?

问题描述

我正在尝试在应用程序GUI中模拟基本恒温器。

I'm trying to simulate a basic thermostat in an application GUI.

我想用新的温度值每2秒更新一个标签盒值。

I want to update a label box value every 2 secs with the new temperature value.

例如，我的初始温度将显示为68度并更新为69，至70等等，每2秒更新75次。

For example, my intial temperature will be displayed as 68 degrees and updated to 69, to 70, etc. till 75 every 2 seconds.

这是我在Java fx中编写的一段代码。 controlpanel 是te形式的对象，其中存在标签框。它仅将最终值更新为75.它不会每2秒更新一次。我写了一个方法暂停导致2秒的延迟。所有标签都会更新其最终值，但不会每2秒更新一次。当我调试时，我可以看到值每2秒增加一个。此代码在按钮onClick事件中编写

This is a piece of code I wrote in Java fx. controlpanel is object of te form where the label box is present. It updates only the final value as 75. It doesnt update it every 2 secs. I have written a method pause to cause a 2 secs delay. All labels are updated with their final values but not updated every 2 secs. When I debug, I can see that the values are increased by one every 2 secs. This code is written in button onClick event

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    int i=0;
    Timer asd = new Timer(1000,null);

    asd.setDelay(1000);

    while(i < 10)
    {
         jTextField1.setText(Integer.toString(i));
         i++;

         asd.start();
    }
 }  

推荐答案

到使用Timer解决你的任务需要用你的代码实现 TimerTask 并使用 Timer＃scheduleAtFixedRate 方法重复运行该代码：

To solve your task using Timer you need to implement TimerTask with your code and use Timer#scheduleAtFixedRate method to run that code repeatedly:

Timer timer = new Timer();
    timer.scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
            System.out.print("I would be called every 2 seconds");
        }
    }, 0, 2000);

另请注意，调用任何UI操作必须在Swing UI线程（或FX UI线程，如果您）上完成正在使用JavaFX）：

Also note that calling any UI operations must be done on Swing UI thread (or FX UI thread if you are using JavaFX):

private int i = 0;
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
    Timer timer = new Timer();
    timer.scheduleAtFixedRate(new TimerTask() {
        @Override
        public void run() {
            SwingUtilities.invokeLater(new Runnable() {
                @Override
                public void run() {
                    jTextField1.setText(Integer.toString(i++));
                }
            });
        }
    }, 0, 2000);
}

如果是JavaFX，您需要在FX UI线程上更新FX控件而不是摆动一个。要实现这一点，请使用 javafx.application.Platform＃runLater 方法而不是 SwingUtilities

In case of JavaFX you need to update FX controls on "FX UI thread" instead of Swing one. To achieve that use javafx.application.Platform#runLater method instead of SwingUtilities

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