Javafx 如何在 GridPane 中定位特定按钮

Question

我正在制作一款带按钮的西洋跳棋游戏。要杀死另一个棋子，你必须将你的棋子沿对角线移动到另一个棋子上，但我不确定如何确保你的棋子移动到另一个棋子上。

我解决这个问题的想法是获取第二个按钮的行和列，这是你的棋子移动到的按钮，然后从每个行和列中减去 1，然后从该按钮获取文本测试它是 "black" 还是 "red".

第一个和第二个 = 按钮

System.out.println((GridPane.getColumnIndex(second) + " vs " + (GridPane.getColumnIndex(second) - 1)));


    if (GridPane.getColumnIndex(second) > 0) {
        System.out.println("checking if a button has been jumped");
        GridPane.setRowIndex(second, (GridPane.getRowIndex(second) - 1));
        GridPane.setColumnIndex(second, (GridPane.getColumnIndex(second) - 1));
        System.out.println("this is a printing of the second button name for location " + (GridPane.getColumnIndex(second)) + " " + (GridPane.getRowIndex(second)) + " " + second.getText());

        if (second.getText().contains("black")) {
            System.out.println("it's a kill");
        } 
        else {
            System.out.println("no kill");
            GridPane.setRowIndex(second, (GridPane.getRowIndex(second) + 1));
            GridPane.setColumnIndex(second, (GridPane.getColumnIndex(second) + 1));
        }
    }

我可以将行和列更改为与另一部分的位置相匹配的内容，但是当我从该按钮（第二个）获取文本时，它不会作为名称返回 "black" 或 "red"，而只是空白按钮的名称。
我的猜测是 GridPane 可能不会像这样工作，我只需要想出另一个解决方案，希望我不必将整个代码重做为二维数组或其他东西。

Answer 1

所以有可能，我从这个post中找到了答案。他只要自己想办法，就能找到具体的位置。 javafx GridPane retrieve specific Cell content

private Node getNodeFromGridPane(GridPane gridPane, int col, int row) {
for (Node node : gridPane.getChildren()) {
    if (GridPane.getColumnIndex(node) == col && GridPane.getRowIndex(node) == row) {
        return node;
    }
}
return null;

}

虽然，为了我自己的目的，我仍然需要弄清楚如何能够测试节点是否包含 "red" 或 "black"，所以我只是添加了这个，现在它一切正常！

private Boolean getNodeFromGridPane(GridPane gridPane, int col, int row) {

    for (Node node : gridPane.getChildren()) {
        if (GridPane.getColumnIndex(node) == col && GridPane.getRowIndex(node) == row) {

            if (node.toString().contains("black")) {

                System.out.println("The second button is black = " + node.toString().contains("black"));

                return true;
            }

            if (node.toString().contains("red")) {

                System.out.println("The second button is red = " + node.toString().contains("red"));

                return true;
            }

        }
    }
    return false;

}

Answer 2

您可以通过遍历 GridPane 个子节点来获取对 GridPane 中节点的引用。
添加一些简单的计算来找到单击的两个按钮之间的对角线，如果有的话：

import java.awt.Toolkit;
import javafx.animation.PauseTransition;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.scene.text.Text;
import javafx.stage.Stage;
import javafx.util.Duration;

public class FxMain extends Application {

    private static final int COLS = 5, ROWS = 5;
    private int clickCounter = 0;
    private GridPane grid;
    private Button first, second;

    @Override
    public void start(Stage primaryStage){

        VBox root = new VBox(10);
        root.setPadding(new Insets(10));
        root.getChildren().addAll(makeGrid(), 
                new Text("Click 2 buttons to find the \n diagonally between them"));
        primaryStage.setScene(new Scene(root));
        primaryStage.sizeToScene();
        primaryStage.show();
    }

    private Pane makeGrid() {

        grid = new GridPane();
        for(int rowIndex = 0; rowIndex < ROWS ; rowIndex++) {
            //an array to hold buttons of one row
            Node[] nodes = new Node[COLS];
            for(int colIndex = 0; colIndex < COLS ; colIndex++) {
                Button node= new Button(rowIndex+""+colIndex);
                node.setOnAction(e->buttonCliked(node)); //add action listener
                nodes[colIndex]= node;
            }
            grid.addRow(rowIndex, nodes);
        }
        return grid;
    }

    private void buttonCliked(Button button) {

        if(clickCounter == 0){
            first = button;
        }else{
            second = button;
            markNode(findMidDiagonalButton());
        }

        System.out.println(clickCounter + " " + button.getText()    );
        clickCounter=  ++clickCounter %2 ;  // changes values between 0 1
    }

    //change node background for a short while, and then reset it
    private void markNode(Node node) {

        if(node == null) return;
        String style = node.getStyle();
        node.setStyle("-fx-background-color: cornflowerblue;");
        PauseTransition pause = new PauseTransition(Duration.seconds(1));
        pause.play();
        pause.setOnFinished(e-> node.setStyle(style));
    }

    private Node findMidDiagonalButton() {

        int rowDelta = GridPane.getRowIndex(first) - GridPane.getRowIndex(second);
        int colDelta = GridPane.getColumnIndex(first) - GridPane.getColumnIndex(second);

        if( Math.abs(rowDelta) != 2 ||  Math.abs(colDelta) != 2 ){
            Toolkit.getDefaultToolkit().beep();
            return null;
        }

        int rowsSum = GridPane.getRowIndex(first) + GridPane.getRowIndex(second);
        int colsSum = GridPane.getColumnIndex(first) + GridPane.getColumnIndex(second);

        return  getNodeByRowCol(Math.abs(rowsSum / 2), Math.abs(colsSum / 2) );
    }

    public Node getNodeByRowCol (int row, int col) {

        for (Node node : grid.getChildren()) {
            if(GridPane.getRowIndex(node) == row && GridPane.getColumnIndex(node) == col)
                return node;
        }

        return null;
    }

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

Javafx 如何在 GridPane 中定位特定按钮

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