帮我用javafx实现拖拽印章图片到pdf中进行pdf盖章效果,要求显示pdf内容,鼠标选中盖章图片按下时可移动印章位置,鼠标松开时保存盖章后的pdf
时间: 2023-07-07 17:17:06 浏览: 73
好的,我会尽力帮您解决这个问题。首先,我们需要导入以下库:
```
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.stage.FileChooser;
import javafx.stage.Stage;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;
```
然后,我们创建一个 JavaFX 应用程序,实现以下步骤:
1. 加载 PDF 文件并将其显示在画布上。
2. 将印章图片加载到 ImageView 中。
3. 实现鼠标拖动印章图片的功能。
4. 保存盖章后的 PDF 文件。
下面是完整的代码:
```java
public class Main extends Application {
private FileChooser fileChooser = new FileChooser();
private File pdfFile;
private ImageView stampImageView;
private boolean isDragging = false;
private double stampX, stampY;
@Override
public void start(Stage primaryStage) throws Exception {
BorderPane root = new BorderPane();
// 加载 PDF 文件并将其显示在画布上
Canvas canvas = new Canvas(600, 800);
GraphicsContext gc = canvas.getGraphicsContext2D();
root.setCenter(canvas);
fileChooser.getExtensionFilters().add(new FileChooser.ExtensionFilter("PDF Files", "*.pdf"));
pdfFile = fileChooser.showOpenDialog(primaryStage);
if (pdfFile != null) {
PDDocument document = PDDocument.load(pdfFile);
PDFRenderer pdfRenderer = new PDFRenderer(document);
Image image = SwingFXUtils.toFXImage(pdfRenderer.renderImage(0), null);
gc.drawImage(image, 0, 0);
document.close();
}
// 将印章图片加载到 ImageView 中
stampImageView = new ImageView(new Image(getClass().getResourceAsStream("stamp.png")));
stampImageView.setPreserveRatio(true);
stampImageView.setFitWidth(100);
root.getChildren().add(stampImageView);
// 实现鼠标拖动印章图片的功能
stampImageView.setOnMousePressed(event -> {
isDragging = true;
stampX = event.getX();
stampY = event.getY();
});
stampImageView.setOnMouseDragged(event -> {
if (isDragging) {
stampImageView.setX(event.getX() - stampX);
stampImageView.setY(event.getY() - stampY);
}
});
stampImageView.setOnMouseReleased(event -> {
isDragging = false;
});
// 保存盖章后的 PDF 文件
Scene scene = new Scene(new Group(root), 600, 800);
primaryStage.setScene(scene);
primaryStage.show();
scene.setOnKeyPressed(event -> {
if (event.getCode().equals(KeyCode.S)) {
FileChooser saveFileChooser = new FileChooser();
saveFileChooser.getExtensionFilters().add(new FileChooser.ExtensionFilter("PDF Files", "*.pdf"));
File saveFile = saveFileChooser.showSaveDialog(primaryStage);
if (saveFile != null) {
try {
PDDocument document = PDDocument.load(pdfFile);
PDPage page = document.getPage(0);
PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true);
SnapshotParameters parameters = new SnapshotParameters();
parameters.setFill(Color.TRANSPARENT);
WritableImage stampImage = stampImageView.snapshot(parameters, null);
BufferedImage bufferedImage = SwingFXUtils.fromFXImage(stampImage, null);
PDImageXObject imageXObject = LosslessFactory.createFromImage(document, bufferedImage);
contentStream.drawImage(imageXObject, (float) stampImageView.getX(), (float) (canvas.getHeight() - stampImageView.getY() - stampImageView.getFitHeight()), (float) stampImageView.getFitWidth(), (float) stampImageView.getFitHeight());
contentStream.close();
document.save(saveFile);
document.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
}
public static void main(String[] args) {
launch(args);
}
}
```
您需要将代码中的 `stamp.png` 替换为您自己的印章图片。按下 `S` 键即可保存盖章后的 PDF 文件。