如何在 javafx 中创建动态可调整大小的形状？

Question

我有三个问题：

1. 我想创建带有框边界的可调整大小的形状...
2. 我还想知道如何让孩子在窗格中被选中。
3. 我正在窗格上创建多个形状。我想更改该形状的某些属性，比如 Fill.. 我该怎么做？？

谢谢

Answer 1

下一个例子将回答你的问题：

• 对于 (1) 它使用绑定，将窗格大小与矩形大小联系起来
• 对于 (2)，它会为每个矩形添加 setOnMouseClick，在 lastOne 字段中存储点击过的矩形。

• 对于（3）见setOnMouseClick()处理程序的代码

  public class RectangleGrid extends Application {
  
    private Rectangle lastOne;
  
    public void start(Stage stage) throws Exception {
      Pane root = new Pane();
  
      int grid_x = 7; //number of rows
      int grid_y = 7; //number of columns
  
      // this binding will find out which parameter is smaller: height or width
      NumberBinding rectsAreaSize = Bindings.min(root.heightProperty(), root.widthProperty());
  
      for (int x = 0; x < grid_x; x++) {
          for (int y = 0; y < grid_y; y++) {
              Rectangle rectangle = new Rectangle();
              rectangle.setStroke(Color.WHITE);
  
              rectangle.setOnMouseClicked(new EventHandler<MouseEvent>() {
                  @Override
                  public void handle(MouseEvent t) {
                      if (lastOne != null) {
                          lastOne.setFill(Color.BLACK);
                      }
                      // remembering clicks
                      lastOne = (Rectangle) t.getSource();
                      // updating fill
                      lastOne.setFill(Color.RED);
                  }
              });
  
              // here we position rects (this depends on pane size as well)
              rectangle.xProperty().bind(rectsAreaSize.multiply(x).divide(grid_x));
              rectangle.yProperty().bind(rectsAreaSize.multiply(y).divide(grid_y));
  
              // here we bind rectangle size to pane size 
              rectangle.heightProperty().bind(rectsAreaSize.divide(grid_x));
              rectangle.widthProperty().bind(rectangle.heightProperty());
  
              root.getChildren().add(rectangle);
          }
      }
  
      stage.setScene(new Scene(root, 500, 500));
      stage.show();
    }
  
    public static void main(String[] args) { launch(); }
  }