每个堆栈窗格都应该具有两个节点。但是,底部的节点在堆栈窗格阵列中的前两个索引的for循环外消失。
public class Main extends Application {
GridPane images;
StackPane[] stackPane;
ImageView cardBack;
ImageView[] cardImages;
@Override
public void start(Stage stage) throws FileNotFoundException {
images = new GridPane(); images.setAlignment(Pos.CENTER);
images.setVgap(5); images.setHgap(5);
cardBack = new ImageView(new Image(new FileInputStream("images/b1fv.gif")));
cardImages = new ImageView[]{
new ImageView(new Image(new FileInputStream("images/c1.gif"))),
new ImageView(new Image(new FileInputStream("images/c2.gif"))),
new ImageView(new Image(new FileInputStream("images/c3.gif")))
};
final Button[] flip = new Button[cardImages.length];
stackPane = new StackPane[cardImages.length];
for (int i = 0; i < cardImages.length; i++) {
stackPane[i] = new StackPane();
stackPane[i].getChildren().addAll(cardBack, cardImages[i]);
images.add(stackPane[i], i, 0, 1, 1);
flip[i] = new Button("Flip");
GridPane.setHalignment(flip[i], HPos.CENTER);
images.add(flip[i], i, 1, 1, 1);
// Debug
System.out.println(stackPane[i].getChildren().toString());
final int j = i;
flip[j].setOnAction(event -> doFlip(j));
}
// Debug
System.out.println("");
for (StackPane pane : stackPane)
System.out.println(pane.getChildren().toString());
stage.setTitle("Assignment 11");
stage.setScene(new Scene(images, 500,200));
stage.show();
}
void doFlip(int loc) {
// Debug
System.out.println("");
for (StackPane pane : stackPane)
System.out.println(pane.getChildren().toString());
ObservableList<Node> children = stackPane[loc].getChildren();
Node topNode = children.get(children.size()-1);
topNode.toBack();
}
public static void main(String[] args) {
launch(args);
}
}
[ImageView@5e1bc54a[styleClass=image-view], ImageView@25389181[styleClass=image-view]]
[ImageView@5e1bc54a[styleClass=image-view], ImageView@ff7cf97[styleClass=image-view]]
[ImageView@5e1bc54a[styleClass=image-view], ImageView@18b8669d[styleClass=image-view]]
[ImageView@25389181[styleClass=image-view]]
[ImageView@ff7cf97[styleClass=image-view]]
[ImageView@5e1bc54a[styleClass=image-view], ImageView@18b8669d[styleClass=image-view]]
[ImageView@25389181[styleClass=image-view]]
[ImageView@ff7cf97[styleClass=image-view]]
[ImageView@5e1bc54a[styleClass=image-view], ImageView@18b8669d[styleClass=image-view]]
在for循环内部显示所有对象。但是,除了数组的最后一个元素外,循环外部没有显示底部节点。
您不能向多个父母添加相同的节点实例!
在循环的顶部您有以下行:
stackPane[i].getChildren().addAll(cardBack, cardImages[i]);
cardBack
节点将添加到所有stackpanes中,但是由于它只能有一个父,因此将将其从上一个删除。Javafx不过提供了一种重用图像资源的方法(我想是您想实现的目标(。您可以在ImageView
构造函数中使用Image
实例,而不是创建一个ImageView
。例如:
cardBack = new Image(new FileInputStream("images/b1fv.gif"));
// some stuff
for (int i = 0; i < cardImages.length; i++) {
stackPane[i] = new StackPane();
stackPane[i].getChildren().addAll(new ImageView(cardBack) , cardImages[i]);
// rest of the loop
}
如果您使用上述Image
和ImageView
,则情况将正常工作。