是否在JavaFx…线程中将项目添加到ListView？

Question

I'm trying to add a string to ListView in JavaFX whilst processing, but it keeps freezing my GUI.

I've tried the following threading - but can't seem to get it to work for a ListView.
Does anybody know how/have an example of how I can update a ListView in JavaFX whilst processing data?

new Thread(new Runnable() {
    @Override public void run() {
        for (int i=1; i<=1000000; i++) {
            final int counter = i;
            Platform.runLater(new Runnable() {
                @Override public void run() {
                    recentList.getItems().add(Integer.toString(counter));
                }
            });
        }
    }}).start();

Answer 1

Using Platform.runLater() is the correct way to go. You could, also, store the String result from Integer.toString(counter) in the background thread (not the UI one). By the way, you should use String.valueOf (there is a thread on StackOverflow which talks about it).

I assume your UI is freezing because of the execution speed of the (very simple) loop.

You should also have a look at Concurrency in JavaFX

Answer 2

Your GUI hangs because you are blocking the JavaFX application thread by calling Platform.runLater() continuously in your Thread.

You can perform a quick fix by adding a sleep statement inside your for-loop to avoid it.

for (int i=1; i<=1000000; i++) {
     final int counter = i;
     Platform.runLater(new Runnable() {
        @Override public void run() {
            recentList.getItems().add(Integer.toString(counter));
        }
     });
     // Add Sleep Time
     Thread.sleep(some milli seconds);
}

To use a more proper and advisable way, use an AnimationTimer , as shown in

JavaFX - Concurrency and updating label

Answer 3

You can do the animation / ui update after adding those strings in the list or use Platform.runLater only once (not advisable):

Platform.runLater(new Runnable() {
  for (int i=1; i<=1000000; i++) {
        final int counter = i;

            @Override public void run() {
                recentList.getItems().add(Integer.toString(counter));
            }
     }
});