ViewportView在JaVa中_在ImageView中缩放图像（javafx）

我不确定你想做什么！我有点使用James_D的建议

好吧我也是初学者，我花了差不多两个小时为你写这篇文章，希望有人读到这篇文章并发现它很有用

我只为png和jpg添加了ExtensionFilters，但你可以添加javaFx支持的任何扩展名

(我使用滑块而不是滚动条导致我讨厌处理滚动条，但我相信你可以自己做)

更新：现在您可以在imageview上拖动以移动视口

package application;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import javafx.application.Application;

import javafx.geometry.Orientation;

import javafx.geometry.Pos;

import javafx.geometry.Rectangle2D;

import javafx.stage.FileChooser;

import javafx.stage.Stage;

import javafx.stage.FileChooser.ExtensionFilter;

import javafx.scene.Cursor;

import javafx.scene.Scene;

import javafx.scene.control.Button;

import javafx.scene.control.Label;

import javafx.scene.control.Slider;

import javafx.scene.control.TextField;

import javafx.scene.image.Image;

import javafx.scene.image.ImageView;

import javafx.scene.layout.BorderPane;

import javafx.scene.layout.GridPane;

import javafx.scene.layout.HBox;

import javafx.scene.layout.VBox;

public class Main extends Application {

static double initx;

static double inity;

static int height;

static int width;

public static String path;

static Scene initialScene,View;

static double offSetX,offSetY,zoomlvl;

@Override

public void start(Stage s) {

s.setResizable(false);

GridPane grid = new GridPane();

grid.setHgap(20);grid.setVgap(20);

grid.setAlignment(Pos.CENTER);

Label hint = new Label("Select Your Image");

TextField URL = new TextField();

URL.setEditable(false);

URL.setPrefWidth(350);

Button browse = new Button("Browse");

FileChooser fc = new FileChooser();

ExtensionFilter png = new ExtensionFilter("png", "*.png");

ExtensionFilter jpg = new ExtensionFilter("jpg", "*.jpg");

fc.getExtensionFilters().addAll(png,jpg);

browse.setOnAction(e->{

URL.setText(fc.showOpenDialog(s).getAbsolutePath());

});

Button open = new Button("Open");

open.setOnAction(e->{

path = URL.getText();

initView();

s.setScene(View);

});

grid.add(hint, 0, 0);

grid.add(URL, 1, 0);

grid.add(browse, 2, 0);

grid.add(open, 2, 1);

initialScene = new Scene(grid,600,100);

s.setScene(initialScene);

s.show();

}

public static void initView(){

VBox root = new VBox(20);

root.setAlignment(Pos.CENTER);

Label title = new Label(path.substring(path.lastIndexOf("\\")+1));

Image source = null;

try {

source = new Image(new FileInputStream(path));

} catch (FileNotFoundException e) {

e.printStackTrace();

}

ImageView image = new ImageView(source);

double ratio = source.getWidth()/source.getHeight();

if(500/ratio < 500) {

width=500;

height=(int) (500/ratio);

}else if(500*ratio < 500){

height=500;

width=(int) (500*ratio);

}else {

height=500;

width=500;

}

image.setPreserveRatio(false);

image.setFitWidth(width);

image.setFitHeight(height);

height = (int) source.getHeight();

width = (int) source.getWidth();

System.out.println("height = "+height+"\nwidth = "+width);

HBox zoom = new HBox(10);

zoom.setAlignment(Pos.CENTER);

Slider zoomLvl = new Slider();

zoomLvl.setMax(4);

zoomLvl.setMin(1);

zoomLvl.setMaxWidth(200);

zoomLvl.setMinWidth(200);

Label hint = new Label("Zoom Level");

Label value = new Label("1.0");

offSetX = width/2;

offSetY = height/2;

zoom.getChildren().addAll(hint,zoomLvl,value);

Slider Hscroll = new Slider();

Hscroll.setMin(0);

Hscroll.setMax(width);

Hscroll.setMaxWidth(image.getFitWidth());

Hscroll.setMinWidth(image.getFitWidth());

Hscroll.setTranslateY(-20);

Slider Vscroll = new Slider();

Vscroll.setMin(0);

Vscroll.setMax(height);

Vscroll.setMaxHeight(image.getFitHeight());

Vscroll.setMinHeight(image.getFitHeight());

Vscroll.setOrientation(Orientation.VERTICAL);

Vscroll.setTranslateX(-20);

BorderPane imageView = new BorderPane();

BorderPane.setAlignment(Hscroll, Pos.CENTER);

BorderPane.setAlignment(Vscroll, Pos.CENTER_LEFT);

Hscroll.valueProperty().addListener(e->{

offSetX = Hscroll.getValue();

zoomlvl = zoomLvl.getValue();

double newValue = (double)((int)(zoomlvl*10))/10;

value.setText(newValue+"");

if(offSetX

offSetX = (width/newValue)/2;

}

if(offSetX>width-((width/newValue)/2)) {

offSetX = width-((width/newValue)/2);

}

image.setViewport(new Rectangle2D(offSetX-((width/newValue)/2), offSetY-((height/newValue)/2), width/newValue, height/newValue));

});

Vscroll.valueProperty().addListener(e->{

offSetY = height-Vscroll.getValue();

zoomlvl = zoomLvl.getValue();

double newValue = (double)((int)(zoomlvl*10))/10;

value.setText(newValue+"");

if(offSetY

offSetY = (height/newValue)/2;

}

if(offSetY>height-((height/newValue)/2)) {

offSetY = height-((height/newValue)/2);

}

image.setViewport(new Rectangle2D(offSetX-((width/newValue)/2), offSetY-((height/newValue)/2), width/newValue, height/newValue));

});

imageView.setCenter(image);

imageView.setTop(Hscroll);

imageView.setRight(Vscroll);

zoomLvl.valueProperty().addListener(e->{

zoomlvl = zoomLvl.getValue();

double newValue = (double)((int)(zoomlvl*10))/10;

value.setText(newValue+"");

if(offSetX

offSetX = (width/newValue)/2;

}

if(offSetX>width-((width/newValue)/2)) {

offSetX = width-((width/newValue)/2);

}

if(offSetY

offSetY = (height/newValue)/2;

}

if(offSetY>height-((height/newValue)/2)) {

offSetY = height-((height/newValue)/2);

}

Hscroll.setValue(offSetX);

Vscroll.setValue(height-offSetY);

image.setViewport(new Rectangle2D(offSetX-((width/newValue)/2), offSetY-((height/newValue)/2), width/newValue, height/newValue));

});

imageView.setCursor(Cursor.OPEN_HAND);

image.setOnMousePressed(e->{

initx = e.getSceneX();

inity = e.getSceneY();

imageView.setCursor(Cursor.CLOSED_HAND);

});

image.setOnMouseReleased(e->{

imageView.setCursor(Cursor.OPEN_HAND);

});

image.setOnMouseDragged(e->{

Hscroll.setValue(Hscroll.getValue()+(initx - e.getSceneX()));

Vscroll.setValue(Vscroll.getValue()-(inity - e.getSceneY()));

initx = e.getSceneX();

inity = e.getSceneY();

});

root.getChildren().addAll(title,imageView,zoom);

View = new Scene(root,(image.getFitWidth())+70,(image.getFitHeight())+150);

}

public static void main(String[] args) {

launch(args);

}

}