Javascript 拖放代码适用于 div，但不适用于 img

Question

我对 JavaScript 还很陌生，所以任何帮助都会很棒!

我创建了这个小代码块，让我可以抓取一个 div 并拖动它。我将“dragme”id 分配给 div，一切都很好。问题是，如果我从 html 中替换该 div 并放置一个 img 元素(显然将“dragme”id 分配给 img)，则事情不会按预期工作。

当我单击并拖动 img 时，它实际上移动了大约 3 或 4 个像素，然后它卡住，直到我抬起鼠标按钮(鼠标向上)。

是否存在某些属性或特征会阻止 img 元素以与 div 相同的方式起作用？

var isClicked = false;
var startClientX = 0;
var startClientY = 0;
var startLeft = 0;
var startTop = 0;

window.addEventListener("load", addListeners, true);

function addListeners()
{
    document.getElementById("dragme").addEventListener("mousedown", mouseIsDown, false);
    document.getElementById("dragme").addEventListener("mouseup", mouseIsUp, false);
    window.addEventListener("mousemove", moveImage, false);

    function mouseIsDown(e)
    {   
        if (isClicked == false)
        {
            isClicked = true;
            startClientX = e.clientX;
            startClientY = e.clientY;
            startLeft = document.getElementById("dragme").offsetLeft;
            startTop = document.getElementById("dragme").offsetTop;
        }
    }

    function mouseIsUp()
    {
        if (isClicked == true)
        {
            isClicked = false;
        }
    }

    function moveImage(e)
    {               
        if (isClicked == true)
        {
            imageLeftDif = e.clientX - startClientX;
            imageTopDif = e.clientY - startClientY;
            var newLeftPos = (startLeft + imageLeftDif) + "px";
            var newTopPos = (startTop + imageTopDif) + "px";    

            document.getElementById("dragme").style.left = newLeftPos;
            document.getElementById("dragme").style.top = newTopPos;
        }
    }   
}

Answer 1

这解决了问题(答案作为 syazdani 的评论提供):

I'd venture to say that the built in browser drag and drop for images is kicking in. Try e.preventDefault and return false in the mousedown handler. – syazdani Dec 2 '12 at 17:26