I have an HTML page which has some draggable elements. Our specs say that hovering mouse on such element the cursor must be grab 
, and during drag cursor must be grabbing 
.
我知道可以设置dropEffect https://developer.mozilla.org/en-US/docs/Web/API/DataTransfer/dropEffect这会更改放置区域上方的光标外观，但选项很少：copy, move, link, and none -- no custom或类似的。
我尝试用 Javascript 和 CSS 更改光标，例如设置cursor: grabbing; when ondragstart被解雇了。但在拖放区域上拖动时，会出现浏览器默认的移动光标。
So the question is: What am I missing to show grabbing cursor () during drag?
不幸的是，我无法在解决方案中使用 JQuery 或其他帮助库。提前致谢！
var onDragStart = function(event) {
event.dataTransfer.setData("Text", event.target.id);
event.currentTarget.classList.add("being-dragged");
};
var onDragEnd = function(event) {
event.currentTarget.classList.remove("being-dragged");
};
var onDragOver = function(event) {
event.preventDefault();
};.dropzone {
width: 500px;
height: 200px;
background-color: silver;
}
.block {
position: absolute;
background-color: pink;
margin: 10px;
border: 20px solid pink;
}
.draggable {
cursor: -webkit-grab;
cursor: grab;
}
.being-dragged {
cursor: -webkit-grabbing;
cursor: grabbing;
background-color: red;
}<div class = "dropzone"
ondragover = "onDragOver(event);"
>
Grab and drag block around
<div class = "draggable block"
draggable = "true"
ondragstart = "onDragStart(event);"
ondragend = "onDragEnd(event);"
>
I'm draggable
</div>
</div>浏览器似乎不允许在拖放操作开始时更改光标。我不知道为什么，但这是一个已知的问题，我相信他们将来会的。
如果 jQuery 不是一个选项，一种可能的解决方法是从头开始实现拖放，使用鼠标事件并克隆源元素：
var onDragStart = function (event) {
event.preventDefault();
var clone = event.target.cloneNode(true);
clone.classList.add("dragging");
event.target.parentNode.appendChild(clone);
var style = getComputedStyle(clone);
clone.drag = {
x: (event.pageX||(event.clientX+document.body.scrollLeft)) - clone.offsetLeft + parseInt(style.marginLeft),
y: (event.pageY||(event.clientY+document.body.scrollTop)) - clone.offsetTop + parseInt(style.marginTop),
source: event.target
};
};
var onDragMove = function (event) {
if (!event.target.drag) {return;}
event.target.style.left = ((event.pageX||(event.clientX+document.body.scrollLeft)) - event.target.drag.x) + "px";
event.target.style.top = ((event.pageY||(event.clientY+document.body.scrollTop)) - event.target.drag.y) + "px";
};
var onDragEnd = function (event) {
if (!event.target.drag) {return;}
// Define persist true to let the source persist and drop the target, otherwise persist the target.
var persist = true;
if (persist || event.out) {
event.target.parentNode.removeChild(event.target);
} else {
event.target.parentNode.removeChild(event.target.drag.source);
}
event.target.classList.remove("dragging");
event.target.drag = null;
};
var onDragOver = function (event) {
event.preventDefault();
};.dropzone {
width: 500px;
height: 200px;
background-color: silver;
}
.block {
position: absolute;
background-color: pink;
margin: 10px;
border: 20px solid pink;
}
.draggable {
position: absolute;
cursor: pointer; /* IE */
cursor: -webkit-grab;
cursor: grab;
}
.dragging {
cursor: -webkit-grabbing;
cursor: grabbing;
background-color: red;
}<div class="dropzone" onmouseover="onDragOver(event);">
Grab and drag block around
<div class = "draggable block"
onmousedown = "onDragStart(event);"
onmousemove = "onDragMove(event);"
onmouseup = "onDragEnd(event);"
onmouseout = "event.out = true; onDragEnd(event);"
>
I'm draggable
</div>
</div>