将C#编写的屏幕区域截图工具类代码转换为可运行的Java版本

功能说明 #

完全对齐原C#代码的核心能力：

• 输入两个坐标点即可截取屏幕指定区域
• 支持按百分比放大输出最终截图
• 全部使用JDK原生API实现，无第三方依赖，不会出现依赖引用错误
• 兼容JDK 8及以上所有版本

完整实现代码 #

import java.awt.AWTException;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class ImageCapture {

    public static void capture(String fileName, Point firstCoordinate, Point secondCoordinate, int enlargeImageByPercentage) throws AWTException, IOException {
        // 拼接临时文件路径，对应原C#的Local/Temp目录
        String tmpDir = System.getProperty("java.io.tmpdir");
        File tmpImgFile = new File(tmpDir, new File(fileName).getName());
        String tmpImgPath = tmpImgFile.getAbsolutePath();

        // 计算截图区域
        int rectX = firstCoordinate.x;
        int rectY = firstCoordinate.y;
        int rectWidth = secondCoordinate.x - firstCoordinate.x;
        int rectHeight = secondCoordinate.y - firstCoordinate.y;
        Rectangle screenRect = new Rectangle(rectX, rectY, rectWidth, rectHeight);

        // 截取屏幕区域
        Robot robot = new Robot();
        BufferedImage bmp = robot.createScreenCapture(screenRect);
        // 保存临时文件
        ImageIO.write(bmp, "jpg", new File(tmpImgPath));

        // 处理目标文件
        File targetFile = new File(fileName);
        if (targetFile.exists()) {
            targetFile.delete();
        }

        if (enlargeImageByPercentage > 0) {
            // 按比例放大图片
            BufferedImage imgToEnlarge = ImageIO.read(new File(tmpImgPath));
            int targetWidth = imgToEnlarge.getWidth() * enlargeImageByPercentage;
            int targetHeight = imgToEnlarge.getHeight() * enlargeImageByPercentage;
            BufferedImage resizedImg = resizeImage(imgToEnlarge, targetWidth, targetHeight);
            ImageIO.write(resizedImg, "jpg", targetFile);
        } else {
            // 直接复制临时文件到目标路径
            java.nio.file.Files.copy(tmpImgFile.toPath(), targetFile.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING);
        }
        // 清理临时文件
        tmpImgFile.deleteOnExit();
    }

    // 重载方法，默认放大比例为0
    public static void capture(String fileName, Point firstCoordinate, Point secondCoordinate) throws AWTException, IOException {
        capture(fileName, firstCoordinate, secondCoordinate, 0);
    }

    private static BufferedImage resizeImage(BufferedImage originalImage, int targetWidth, int targetHeight) {
        float sourceWidth = originalImage.getWidth();
        float sourceHeight = originalImage.getHeight();
        // 计算等比缩放比例，对应原C#的逻辑，避免拉伸变形
        float percentW = targetWidth / sourceWidth;
        float percentH = targetHeight / sourceHeight;
        float finalPercent = Math.min(percentW, percentH);

        int destWidth = (int) (sourceWidth * finalPercent);
        int destHeight = (int) (sourceHeight * finalPercent);

        BufferedImage resizedImage = new BufferedImage(destWidth, destHeight, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = resizedImage.createGraphics();
        // 对应原C#的HighQualityBicubic插值模式，保证缩放质量
        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
        g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
        g.drawImage(originalImage, 0, 0, destWidth, destHeight, null);
        g.dispose();

        return resizedImage;
    }
}

使用示例 #

public class Test {
    public static void main(String[] args) throws Exception {
        // 示例：截取屏幕(0,0)到(500,500)的区域，放大2倍后保存到d:/test.jpg
        Point p1 = new Point(0, 0);
        Point p2 = new Point(500, 500);
        ImageCapture.capture("d:/test.jpg", p1, p2, 2);
    }
}

内容的提问来源于stack exchange，提问作者nabila