我正在开发一个学校项目，创建一个简单的战舰游戏，我想使用拖放功能将按钮从屏幕底部的HBox拖动到玩家用来放置船只的GridPane。但我不能让它正常工作。这是现在的picture of my board。
我试过使用button.setOnMouseDragged（e - > {CODE HERE}）;但它不起作用。
public class GridOrganizer {
private BorderPane borderPane;
public GridOrganizer() {
borderPane = new BorderPane();
borderPane.setStyle("-fx-background-color: grey;");
borderPane.setPrefHeight(600);
borderPane.setPrefWidth(600);
createGrid();
}
public void createGrid() {
//Creates the grids where the game is played and buttons/ships to place on grid
GridPane playerGrid = new GridPane();
GridPane enemyGrid = new GridPane();
Insets padding = new Insets(10);
//Create playergrid
for (int i = 0; i < 10; i++) {
playerGrid.getColumnConstraints().add(new ColumnConstraints(50)); //50 wide
playerGrid.getRowConstraints().add(new RowConstraints(50));
}
//Create enemygrid
for (int i = 0; i < 10; i++) {
enemyGrid.getColumnConstraints().add(new ColumnConstraints(50)); //50 wide
enemyGrid.getRowConstraints().add(new RowConstraints(50));
}
//looping through row and columns and adds buttons
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
Button button = new Button();
button.setPrefHeight(50);
button.setPrefWidth(50);
GridPane.setConstraints(button, j, i); //(button, column, row)
playerGrid.getChildren().add(button); //add button on each index
button.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
//HIT or MISS
System.out.println("Row: " + GridPane.getRowIndex(button) + ", Column: " + GridPane.getColumnIndex(button));
button.setStyle("-fx-background-color: grey;");
}
});
}
}
//..same with enemy grid
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 10; j++) {
Button button = new Button();
button.setPrefHeight(50);
button.setPrefWidth(50);
GridPane.setConstraints(button, j, i); //(button, column, row)
enemyGrid.getChildren().add(button); //add button on each index
button.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
System.out.println("Row: " + GridPane.getRowIndex(button) + ", Column: " + GridPane.getColumnIndex(button));
button.setStyle("-fx-background-color: grey;");
}
});
}
}
//Make buttons for the ships
Button rowboat = new Button("Rowboat");
Button sailboat = new Button("Sailboat");
Button submarine = new Button("Submarine");
Button destroyer = new Button("Destroyer");
Button battleship = new Button("Battleship");
//Size the ship buttons to match game description
battleship.setPrefHeight(50);
battleship.setPrefWidth(250); //size 5
destroyer.setPrefHeight(50);
destroyer.setPrefWidth(200); //size 4
submarine.setPrefHeight(50);
submarine.setPrefWidth(150); //size 3
sailboat.setPrefHeight(50);
sailboat.setPrefWidth(150); //size 3
rowboat.setPrefHeight(50);
rowboat.setPrefWidth(100); //size 2
//Drags button
rowboat.setOnMouseDragged(e -> {
//CODE HERE
});
//Drops button on grid
//CODE HERE
sailboat.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
//PLACE SHIP
}
});
submarine.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
//PLACE SHIP
}
});
destroyer.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
//PLACE SHIP
}
});
battleship.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent arg0) {
//PLACE SHIP
}
});
HBox ships = new HBox(); //Horizontal box
ships.getChildren().addAll(rowboat, sailboat, submarine, destroyer, battleship); //Add buttons to horizontal box
//Add grids and ship buttons to pane with padding
borderPane.setLeft(enemyGrid);
BorderPane.setMargin(enemyGrid, padding);
borderPane.setRight(playerGrid);
BorderPane.setMargin(playerGrid, padding);
borderPane.setBottom(ships);
BorderPane.setMargin(ships, padding);
}
public Pane getGrid() {
return borderPane;
}
}
这里的计划是使用拖动事件完成时创建按钮所需的数据来启动拖动事件。在您的代码中，看起来您已经将Buttons添加到Grid中。这意味着您只需要传输String来更改Button's文本。在我的代码中，我在创建StackPane时使用Grid。然后我创建并添加Buttons。你的方法可能会更好。我看上去那么远。我添加了一个MCVE（来自here的更改代码）：
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.input.*;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
/**
* Demonstrates a drag-and-drop feature.
*/
public class HelloDragAndDrop extends Application
{
@Override
public void start(Stage stage)
{
//Source Buttons.
final Button boat1 = new Button("boat1");
final Button boat2 = new Button("boat2");
final Button boat3 = new Button("boat3");
final Button boat4 = new Button("boat4");
//Adding OnDragDetected to source Buttons.
setOnDragDetected(boat1);
setOnDragDetected(boat2);
setOnDragDetected(boat3);
setOnDragDetected(boat4);
//Adding onDragDone to source Buttons.
setOnDragDone(boat1);
setOnDragDone(boat2);
setOnDragDone(boat3);
setOnDragDone(boat4);
//Creating GridPane
GridPane gridPane = new GridPane();
gridPane.setVgap(5);
gridPane.setHgap(5);
gridPane.setPadding(new Insets(5, 5, 5, 5));
gridPane.setStyle("-fx-background-color: black;");
//Adding StackPane to every Cell in the GridPane and Adding the Target Events to each StackPane.
for (int i = 0; i < 6; i++) {
StackPane stackPane = new StackPane();
stackPane.setPrefSize(150, 50);
stackPane.setStyle("-fx-background-color: yellow;");
setOnDragOver(stackPane);
setOnDragEntered(stackPane);
setOnDragExited(stackPane);
setOnDragDropped(stackPane);
gridPane.add(stackPane, i / 3, i % 3);
}
HBox root = new HBox(new VBox(boat1, boat2, boat3, boat4), gridPane);
stage.setTitle("Hello Drag And Drop");
Scene scene = new Scene(root, 400, 200);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args)
{
Application.launch(args);
}
//source events handlers
public void setOnDragDetected(Button source)
{
source.setOnDragDetected((MouseEvent event) -> {
/* drag was detected, start drag-and-drop gesture*/
System.out.println("onDragDetected");
/* allow any transfer mode */
Dragboard db = source.startDragAndDrop(TransferMode.ANY);
/* put a string on dragboard */
ClipboardContent content = new ClipboardContent();
content.putString(source.getText());
db.setContent(content);
event.consume();
});
}
public void setOnDragDone(Button source)
{
source.setOnDragDone((DragEvent event) -> {
/* the drag-and-drop gesture ended */
System.out.println("onDragDone");
/* if the data was successfully moved, clear it */
// if (event.getTransferMode() == TransferMode.MOVE) {
// source.setText("");
// }
event.consume();
});
}
//target event handlers
public void setOnDragOver(StackPane target)
{
target.setOnDragOver((DragEvent event) -> {
/* data is dragged over the target */
System.out.println("onDragOver");
/* accept it only if it is not dragged from the same node
* and if it has a string data */
if (event.getGestureSource() != target
&& event.getDragboard().hasString()) {
/* allow for both copying and moving, whatever user chooses */
event.acceptTransferModes(TransferMode.COPY_OR_MOVE);
}
event.consume();
});
}
public void setOnDragEntered(StackPane target)
{
target.setOnDragEntered((DragEvent event) -> {
/* the drag-and-drop gesture entered the target */
System.out.println("onDragEntered");
/* show to the user that it is an actual gesture target */
if (event.getGestureSource() != target
&& event.getDragboard().hasString()) {
target.setStyle("-fx-background-color: green;");
}
event.consume();
});
}
public void setOnDragExited(StackPane target)
{
target.setOnDragExited((DragEvent event) -> {
/* mouse moved away, remove the graphical cues */
target.setStyle("-fx-background-color: transparent;");
event.consume();
});
}
public void setOnDragDropped(StackPane target)
{
target.setOnDragDropped((DragEvent event) -> {
/* data dropped */
System.out.println("onDragDropped");
/* if there is a string data on dragboard, read it and use it */
Dragboard db = event.getDragboard();
boolean success = false;
if (db.hasString()) {
//target.setText(db.getString());
Button tempBoat = new Button(db.getString());
tempBoat.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE);
target.getChildren().clear();
target.getChildren().add(tempBoat);
success = true;
}
/* let the source know whether the string was successfully
* transferred and used */
event.setDropCompleted(success);
event.consume();
});
}
}
在这段代码中，代表Buttons的Boats都附有onDragDetected和onDragDone事件处理程序。它们被认为是Source / Drag事件的开始。对于GridPane中的每个细胞，添加了StackPane。这些StackPanes被认为是Target /区域拖放事件。每个StackPane都附有onDragOver，onDragEntered，onDragDropped和onDragExited。一旦拖拽事件完成，接收事件的StackPane / Target将获得一个新的Button作为一个与Source Button同名的孩子。