JavaFX延迟绘制形状

Question

如何延迟绘制形状？ 例如，在开始时绘制几个矩形，1秒钟后绘制fillOval，3秒后绘制另一个椭圆形等等。

Answer 1

您正在描述动画。为此，您应该使用Animation API。

例如，使用Timeline：

import java.util.ArrayList; 
import java.util.List; 
import java.util.Random; 

import javafx.animation.KeyFrame; 
import javafx.animation.Timeline; 
import javafx.application.Application; 
import javafx.scene.Scene; 
import javafx.scene.layout.Pane; 
import javafx.scene.paint.Color; 
import javafx.scene.shape.Ellipse; 
import javafx.scene.shape.Rectangle; 
import javafx.stage.Stage; 
import javafx.util.Duration; 

public class ShapeAnimationExample extends Application { 

    private final Random rng = new Random(); 


    @Override 
    public void start(Stage primaryStage) { 


     List<Rectangle> fewRectangles = new ArrayList<>(); 
     for (int i = 0 ; i < 5 ; i++) { 
      Rectangle r = new Rectangle(rng.nextInt(300)+50, rng.nextInt(300)+50, rng.nextInt(100)+50, rng.nextInt(100)+50); 
      r.setFill(randomColor()); 
      fewRectangles.add(r); 
     } 

     List<Ellipse> ovals = new ArrayList<>(); 
     for (int i = 0 ; i < 5 ; i++) { 
      Ellipse e = new Ellipse(rng.nextInt(400)+50, rng.nextInt(400)+50, rng.nextInt(50)+50, rng.nextInt(50)+50); 
      e.setFill(randomColor()); 
      ovals.add(e); 
     } 

     Pane pane = new Pane(); 
     pane.setMinSize(600, 600); 

     Timeline timeline = new Timeline(); 
     Duration timepoint = Duration.ZERO ; 
     Duration pause = Duration.seconds(1); 

     KeyFrame initial = new KeyFrame(timepoint, e -> pane.getChildren().addAll(fewRectangles)); 
     timeline.getKeyFrames().add(initial); 

     for (Ellipse oval : ovals) { 
      timepoint = timepoint.add(pause); 
      KeyFrame keyFrame = new KeyFrame(timepoint, e -> pane.getChildren().add(oval)); 
      timeline.getKeyFrames().add(keyFrame); 
     } 

     Scene scene = new Scene(pane); 
     primaryStage.setScene(scene); 
     primaryStage.show(); 

     timeline.play(); 
    } 

    private Color randomColor() { 
     return new Color(rng.nextDouble(), rng.nextDouble(), rng.nextDouble(), 1.0); 
    } 

    public static void main(String[] args) { 
     launch(args); 
    } 
}