JavaFX Node.snapshot（）从工作线程调用时冻结线程，想法？

Question

I need to write a javafx.scene.canvas.Canvas to a javafx.scene.image.WritableImage . I am aware that the snapshot() method in javafx.scene.Node will perform this, and it works great when I'm on the JavaFX Application thread.

But I need to perform this write from a worker thread that utilizes the javafx.concurrent package. So I have a javafx.concurrent.Task<V> that attempts to call the snapshot() method from within its call() method. When attempting to do this, the thread freezes when it calls snapshot() .

So my question is am I allowed to call snapshot() from a worker thread from that utilizes the javafx.concurrent package?

Answer 1

Try Platfrom#runLater() which was introduced exactly for this kind of tasks: http://docs.oracle.com/javafx/2/api/javafx/application/Platform.html#runLater(java.lang.Runnable)

Platform.runLater(new Runnable() {
    public void run() {
        myNode.snapshot(...)
    }
}

You can run this code from the any thread, but snapshot() method would be called on FX App Thread as required.