我有一个使用Apache PdfBox开发的pdf阅读器，我的问题是缩放后我的图像模糊，即使pdf文件的分辨率非常好，这个问题也只存在于PDF中。此代码可与png或jpg文件一起很好地工作，但pdf文件仍然存在问题，我真的很困惑，我在google上搜索，但发现一些解决方案不完整。
控制器
package application;
import java.nio.file.Paths;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.property.DoubleProperty;
import javafx.beans.property.SimpleDoubleProperty;
import javafx.fxml.FXML;
import javafx.scene.control.ScrollPane;
import javafx.scene.control.ScrollPane.ScrollBarPolicy;
import javafx.scene.image.ImageView;
import javafx.scene.layout.VBox;
public class Controller {
String imagePath = "C:\\Users\\piratack007\\Desktop\\1.jpg";
private ImageView imageView = new ImageView();
String path="C:\\Users\\piratack007\\Desktop\\file.pdf";
private PdfModel model= new PdfModel(Paths.get(path));
private ScrollPane scrollPane = new ScrollPane();
private DoubleProperty zoom = new SimpleDoubleProperty(1.1);
private PageDimensions currentPageDimensions ;
@FXML private VBox vbox;
String cssLayout = "-fx-border-color: red;\n" +
"-fx-border-insets: 5;\n" +
"-fx-border-width: 3;\n" +
"-fx-border-style: dashed;\n";
String scrollCssLayout= "-fx-border-color: green;\n" +
"-fx-border-insets: 5;\n" +
"-fx-border-width: 3;\n" +
"-fx-border-style: dashed;\n"+
//Ne pas afficher le petit trait gris
"-fx-background-color:transparent";
public void initialize() {
afficheImage();
}
void afficheImage() {
/*try {
imageView = new ImageView(new Image(new FileInputStream(imagePath)));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
//loading the first page
imageView = new ImageView(model.getImage(0));
System.out.print("1-imageView.getFitHeight(): "+imageView.getImage().getHeight()+"\n");
System.out.print("imageView.getFitWidth(): "+imageView.getImage().getWidth()+"\n");
currentPageDimensions = new PageDimensions(imageView.getImage().getWidth(), imageView.getImage().getHeight());
zoom.addListener(new InvalidationListener() {
@Override
public void invalidated(Observable arg0) {
//My problem is in this part of code
int width = (int) (imageView.getImage().getWidth() * zoom.get());
int height = (int) (imageView.getImage().getHeight() * zoom.get());
imageView.setFitWidth(width);
System.out.print("Largeur: "+ (width) +"px\n");
imageView.setFitHeight(height);
System.out.print("Hauteur: "+ height +"px\n");
//==================================================
}
});
imageView.preserveRatioProperty().set(true);
scrollPane.setPannable(true);
scrollPane.setStyle(scrollCssLayout);
scrollPane.setVbarPolicy(ScrollBarPolicy.AS_NEEDED);
scrollPane.setHbarPolicy(ScrollBarPolicy.AS_NEEDED);
scrollPane.setContent(imageView);
vbox.setStyle(cssLayout);
vbox.getChildren().add(scrollPane);
}
@FXML private void zoomIn() {
zoom.set(zoom.get()*1.1);
// System.out.print("zoom.get(): "+zoom.get()*100 +"%\n");
}
@FXML private void zoomOut() {
zoom.set(zoom.get()/1.1);
// System.out.print("zoom.get(): "+zoom.get()*100 +"%\n");
}
@FXML private void zoomFit() {
}
@FXML private void zoomWidth() {
}
private class PageDimensions {
private double width ;
private double height ;
PageDimensions(double width, double height) {
this.width = width ;
this.height = height ;
}
@Override
public String toString() {
return String.format("[%.1f, %.1f]", width, height);
}
}
}
PdfModel
package application;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.file.Path;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.Image;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.rendering.PDFRenderer;
/**
* @author toru
*/
class PdfModel {
//private static final Logger logger = Logger.getLogger(PdfModel.class.getName());
private PDDocument document;
private PDFRenderer renderer;
Path chemin;
PdfModel() {
}
PdfModel(Path path) {
try {
chemin=path;
document = PDDocument.load(path.toFile());
renderer = new PDFRenderer(document);
} catch (IOException ex) {
throw new UncheckedIOException("PDDocument thorws IOException file=" + path, ex);
}
}
int nombreDePages() {
return document.getPages().getCount();
}
PDPage getPage (int num) {
PDPage page = document.getPage(num);
return page;
}
void fermer() {
try {
document.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
void setPath(Path pPays)
{
chemin = pPays;
System.out.println("On est dans la page pdfmodel");
System.out.println("Path: "+pPays);
}
Image getImage(int pageNumber) {
BufferedImage pageImage;
try {
pageImage = renderer.renderImage(pageNumber);
} catch (IOException ex) {
throw new UncheckedIOException("PDFRenderer throws IOException", ex);
}
return SwingFXUtils.toFXImage(pageImage, null);
}
}
ui.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="10.0" minWidth="10.0" prefHeight="400.0" prefWidth="400.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.Controller">
<bottom>
<HBox prefHeight="50.0" prefWidth="400.0" BorderPane.alignment="CENTER">
<children>
<Button mnemonicParsing="false" onAction="#zoomIn" text="+">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomOut" text="-">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomFit" text="ZoomFit">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
<Button mnemonicParsing="false" onAction="#zoomWidth" text="ZoomWidth">
<HBox.margin>
<Insets left="5.0" top="5.0" />
</HBox.margin>
</Button>
</children>
</HBox>
</bottom>
<center>
<VBox fx:id="vbox" prefHeight="350.0" prefWidth="400.0" BorderPane.alignment="CENTER" />
</center>
</BorderPane>
Main.java
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
/**
*@author toru
*/
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception {
final Parent parent = FXMLLoader.load(getClass().getResource("ui.fxml"));
primaryStage.setTitle("Zoom ImageView Demo ");
primaryStage.setScene(new Scene(parent,800, 600));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
最诚挚的问候
使用二参数renderImage()方法。第二个参数是比例。 1是默认值，是72 dpi，4是288 dpi，通常很好。因此，我建议您从比例尺4开始，并在以后的步骤中增加缩放比例（请注意，在高分辨率下渲染可能会变慢）。