Selenium Web驱动程序项目中的构造函数未定义

Question

在Selenium Web Driver项目中，构造函数DragAndDrop（WebDriver）在dragAndDropTest（）中变得未定义，有人可以建议如何解决此问题吗？我添加了错误屏幕截图和span元素详细信息

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.interactions.Action;
import org.openqa.selenium.interactions.Actions;

public class DragAndDrop {  
    WebDriver driver;

    public DragAndDrop(WebDriver driver){
        this.driver = driver;
    }

    public void draganItem(){
           //Element on which need to drag.
        WebElement source = driver.findElement(By.xpath("//div[@id='todrag']/span"));
            //Element on which need to drop.        
        WebElement target =driver.findElement(By.id("mydropzone"));                 
            //Using Actions class for drag and drop.        
        Actions act = new Actions(driver);                  
           //Using Action for Dragged and dropped.
        Action dragAndDrop = act.moveToElement(source)
                                .clickAndHold(source)
                                .moveToElement(target)
                                .release(target)
                                .build();
                                dragAndDrop.perform();      
                            }

    public String droppedItem(){
        return driver.findElement(By.id("droppedlist")).getText();      
    }



}

//下面是DragAndDropTest测试//

public class DragAndDropTest {  

        @Test
        public void dragAndDropTest(){
            System.setProperty("webdriver.chrome.driver", "C:\\Project\\Selenium\\chromedriver.exe");   
            WebDriver driver = new ChromeDriver();
            driver.get("http://www.seleniumeasy.com/test/drag-and-drop-demo.html");
            driver.manage().window().maximize();
            DragAndDrop dragandDrop = new DragAndDrop(driver);



        }

    }