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The dragenter event is fired when a dragged element or text selection enters a valid drop target.

General info

Bubbles Yes
Cancelable Yes
Target objects The immediate user selection (the element directly indicated by the user as the drop target), or the <body> element.
Interface DragEvent
Default Action Reject immediate user selection as potential target element.

Properties

Property Type Description
target Read only EventTarget The element underneath the element being dragged.
type Read only DOMString The type of event.
bubbles Read only Boolean Whether the event normally bubbles or not
cancelable Read only Boolean Whether the event is cancellable or not?
view Read only WindowProxy document.defaultView (window of the document)
detail Read only long (float) 0.
dataTransfer DataTransfer The data that underlies a drag-and-drop operation, known as the drag data store. Protected mode.
currentTarget Read only EventTarget The node that had the event listener attached.
relatedTarget Read only EventTarget For mouseover, mouseout, mouseenter and mouseleave events: the target of the complementary event (the mouseleave target in the case of a mouseenter event). null otherwise.
screenX Read only long The X coordinate of the mouse pointer in global (screen) coordinates.
screenY Read only long The Y coordinate of the mouse pointer in global (screen) coordinates.
clientX Read only long The X coordinate of the mouse pointer in local (DOM content) coordinates.
clientY Read only long The Y coordinate of the mouse pointer in local (DOM content) coordinates.
button Read only unsigned short The button number that was pressed when the mouse event was fired: Left button=0, middle button=1 (if present), right button=2. For mice configured for left handed use in which the button actions are reversed the values are instead read from right to left.
buttons Read only unsigned short The buttons being pressed when the mouse event was fired: Left button=1, Right button=2, Middle (wheel) button=4, 4th button (typically, "Browser Back" button)=8, 5th button (typically, "Browser Forward" button)=16. If two or more buttons are pressed, returns the logical sum of the values. E.g., if Left button and Right button are pressed, returns 3 (=1 | 2). More info.
mozPressure Read only float The amount of pressure applied to a touch or tabdevice when generating the event; this value ranges between 0.0 (minimum pressure) and 1.0 (maximum pressure).
ctrlKey Read only boolean true if the control key was down when the event was fired. false otherwise.
shiftKey Read only boolean true if the shift key was down when the event was fired. false otherwise.
altKey Read only boolean true if the alt key was down when the event was fired. false otherwise.
metaKey Read only boolean true if the meta key was down when the event was fired. false otherwise.

Example

<div class="dropzone">
  <div id="draggable" draggable="true" ondragstart="event.dataTransfer.setData('text/plain',null)">
    This div is draggable
  </div>
</div>
<div class="dropzone"></div>
<div class="dropzone"></div>
<div class="dropzone"></div>

<style>
  #draggable {
    width: 200px;
    height: 20px;
    text-align: center;
    background: white;
  }

  .dropzone {
    width: 200px;
    height: 20px;
    background: blueviolet;
    margin-bottom: 10px;
    padding: 10px;
  }
</style>

<script>
  var dragged;

  /* events fired on the draggable target */
  document.addEventListener("drag", function( event ) {

  }, false);

  document.addEventListener("dragstart", function( event ) {
      // store a ref. on the dragged elem
      dragged = event.target;
      // make it half transparent
      event.target.style.opacity = .5;
  }, false);

  document.addEventListener("dragend", function( event ) {
      // reset the transparency
      event.target.style.opacity = "";
  }, false);

  /* events fired on the drop targets */
  document.addEventListener("dragover", function( event ) {
      // prevent default to allow drop
      event.preventDefault();
  }, false);

  document.addEventListener("dragenter", function( event ) {
      // highlight potential drop target when the draggable element enters it
      if ( event.target.className == "dropzone" ) {
          event.target.style.background = "purple";
      }

  }, false);

  document.addEventListener("dragleave", function( event ) {
      // reset background of potential drop target when the draggable element leaves it
      if ( event.target.className == "dropzone" ) {
          event.target.style.background = "";
      }

  }, false);

  document.addEventListener("drop", function( event ) {
      // prevent default action (open as link for some elements)
      event.preventDefault();
      // move dragged elem to the selected drop target
      if ( event.target.className == "dropzone" ) {
          event.target.style.background = "";
          dragged.parentNode.removeChild( dragged );
          event.target.appendChild( dragged );
      }
    
  }, false);
</script>

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'dragenter' in that specification.
Living Standard  
HTML5.1
The definition of 'dragenter' in that specification.
Working Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 4 3.5 (1.9.1)[1] 10 12 3.1
Feature Android Android Webview Chrome for Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile
Basic support No support No support No support No support No support 10 No support No support

[1] dragenter event is fired twice when the dropzone is parent of draggable or draggable itself. See bug 804036.

See also

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 最近更新: WhiteHawk-taka,