import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import org.apache.commons.io.FileUtils;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.Point;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
public class ScreenShot {
    public  void screenShotForElement(WebDriver driver,WebElement element, String path,int x,int y) throws InterruptedException {
        //截取整个页面的图片
        File scrFile = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE);
        try {
            //获取元素在所处frame中位置对象
            Point p = element.getLocation();
            //获取元素的宽与高
            int width = element.getSize().getWidth();
            int height = element.getSize().getHeight();
            //矩形图像对象
            Rectangle rect = new Rectangle(width, height);
            BufferedImage img = ImageIO.read(scrFile);
            //x、y表示加上当前frame的左边距,上边距
            BufferedImage dest = img.getSubimage(p.getX()+x, p.getY()+y,rect.width, rect.height);
            ImageIO.write(dest, "png", scrFile);
            FileUtils.copyFile(scrFile, new File(path));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

Webdriver中实现区域截图的方式以及如何截取frame中的图片