一、鼠标滚动放大缩小图片
package cn.util;import java.io.File;import javafx.application.Application;import javafx.beans.value.ChangeListener;import javafx.beans.value.ObservableValue;import javafx.geometry.Point2D;import javafx.geometry.Rectangle2D;import javafx.scene.Scene;import javafx.scene.image.Image;import javafx.scene.image.ImageView;import javafx.scene.input.MouseDragEvent;import javafx.scene.input.ScrollEvent;import javafx.scene.layout.Pane;import javafx.scene.layout.StackPane;import javafx.stage.Stage;/**** @author MK*/public class ImageApplication extends Application {Point2D dragDistance = null;public void start(Stage primaryStage) {ImageView imageView = new ImageView();String file = new File("picture1.png").toURI().toString();System.out.println(file);Image image = new Image(file);imageView.setImage(image);final double w = image.getWidth();final double h = image.getHeight();final double max = Math.max(w, h);final int width = (int) (500 * w / max);final int heigth = (int) (500 * h / max);imageView.setFitHeight(heigth);imageView.setFitWidth(width);Pane pane = new Pane();StackPane stackPane = new StackPane(pane);Scene scene = new Scene(stackPane, 700, 800);pane.getChildren().add(imageView);pane.heightProperty().addListener(new ChangeListener<Number>() {@Overridepublic void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {imageView.setY((newValue.doubleValue() - imageView.getFitHeight()) / 2);}});pane.widthProperty().addListener(new ChangeListener<Number>() {@Overridepublic void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {imageView.setX((newValue.doubleValue() - imageView.getFitWidth()) / 2);}});final double scale = 5;stackPane.addEventFilter(ScrollEvent.SCROLL, event -> {double rate = 0;if (event.getDeltaY() > 0) {rate = 0.05;} else {rate = -0.05;}double newWidth = imageView.getFitWidth() + w * rate;double newHeight = imageView.getFitHeight() + h * rate;if (newWidth <= width || newWidth > scale * width ) {return;}Point2D eventPoint = new Point2D(event.getSceneX(), event.getSceneY());Point2D imagePoint = pane.localToScene(new Point2D(imageView.getX(), imageView.getY()));Rectangle2D imageRect = new Rectangle2D(imagePoint.getX(), imagePoint.getY(), imageView.getFitWidth(), imageView.getFitHeight());Point2D ratePoint;Point2D eventPointDistance;if (newWidth > scale / 4 * width && imageRect.contains(eventPoint)) {ratePoint = eventPoint.subtract(imagePoint);ratePoint = new Point2D(ratePoint.getX() / imageView.getFitWidth(), ratePoint.getY() / imageView.getFitHeight());eventPointDistance = pane.sceneToLocal(eventPoint);} else {ratePoint = new Point2D(0.5, 0.5);eventPointDistance = new Point2D(pane.getWidth() / 2,pane.getHeight() / 2);}imageView.setX(eventPointDistance.getX() - newWidth * ratePoint.getX());imageView.setY(eventPointDistance.getY() - newHeight * ratePoint.getY());imageView.setFitWidth(newWidth);imageView.setFitHeight(newHeight);});primaryStage.setScene(scene);primaryStage.show();}public static void main(String[] args) {launch(args);}}
