自定义光标，可拖放不带库的HTML元素

Question

我知道可以设置dropEffect，以更改拖放区上方的光标外观，但几乎没有选项：复制，移动，链接，以及无——无自定义或类似选项。

我曾尝试用Javascript和CSS更改游标，比如设置cursor:grabbing 当ondragstart被触发时。但在拖放区域上拖动时，浏览器会显示默认的移动光标。

不幸的是，我不能在解决方案中使用JQuery或其他帮助库。提前谢谢！

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>




Answer 1

为了弄明白这一点，我经历了很多痛苦。公认的答案是web上的最佳答案，但现在的最佳实践是使用元素的。setPointerCapture事件，该事件允许您监听元素上类似拖动的行为并对其进行操作，而无需被限制在拖动API的狭窄行为中。一种方法是：

el.onpointerdown = ev => {
    el.onpointermove = pointerMove 
    el.setPointerCapture(ev.pointerId)
}

pointerMove = ev => {
    console.log('Dragged!')
}

el.onpointerup = ev => {
    el.onpointermove = null
    el.releasePointerCapture(ev.pointerId)
}

最明显的礼物是，这里没有发现偷袭后门的光标劫持行为。

Answer 2

这是一个已知的问题在这里报告

拖动时，光标会自动变为正常。

我的尝试给了我以下几点。在带有抓取游标的元素上给出一个活动的。当它处于活动状态时，光标将更改，但一旦您启动拖动，它将自动更改。

我试图设置body光标在dragstart上抓取，但没有结果。甚至它也不起作用。

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();
};

css prettyprint-override">.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;
}

.draggable:active{
    cursor : -moz-grabbing;
    cursor: -webkit-grabbing;
    cursor: grabbing;
}
.being-dragged{
    background-color: red;
    cursor : -moz-grabbing;
    cursor: -webkit-grabbing;
    cursor: grabbing;
}

<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>

Answer 3

浏览器似乎不允许在拖动开始时更改光标

如果jQuery不是一个选项，一种可能的解决方法是实现一个拖动

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>