使用贪婪选项进行拖放


说明

如果将此选项设置为 true(默认值),它将停止处理悬停在可拖放项上方的其他项目,将不会搜索可拖放项下方。

语法

Droppables.add('element', {greedy: false or true});

示例

逐个将 greedy 设置为 true 和 false,尝试此示例。你会发现如果你将 greedy 设置为 false,则你无法将项目拖到目标区域。

<html>
   <head>
      <title>Drag and Drop Example</title>
		
      <script type = "text/javascript" src = "/javascript/prototype.js"></script>
      <script type = "text/javascript" src = "/javascript/scriptaculous.js"></script>
		
      <script type = "text/javascript">

         window.onload = function() {
			
            // Make all the images draggables from draggables division.
				
            $A($('draggables').getElementsByTagName('img')).each(function(item) {
               new Draggable(item, {revert: true, ghosting: true});
            });

            Droppables.add('droparea',
               {
                  hoverclass: 'hoverActive',
                  greedy: false,
                  onDrop: moveItem
               }
            );
				
            // Set drop area by default  non cleared.
            $('droparea').cleared = false;
         }
			
         // The target drop area contains a snippet of instructional
         // text that we want to remove when the first item
         // is dropped into it.
			
         function moveItem( draggable,droparea){
            if (!droparea.cleared) {
               droparea.innerHTML = '';
               droparea.cleared = true;
            }
				
            draggable.parentNode.removeChild(draggable);
            droparea.appendChild(draggable);
         }
      </script>
		
      <style type = "text/css">
         #draggables {
            width: 172px;
            border: 3px ridge blue;
            float: left;
            padding: 9px;
         }
			
         #droparea {
            float: left;
            margin-left: 16px;
            width: 172px;
            border: 3px ridge maroon;
            text-align: center;
            font-size: 24px;
            padding: 9px;
            float: left;
         }
			
         .hoverActive {
            background-color: #ffffcc;
         }
			
         #draggables img, #droparea img {
            margin: 4px;
            border:1px solid red;
         }
      </style>
   </head>
   
   <body>
      <div id = "draggables">
         <img src = "/images/html.gif"/>
         <img src = "/images/css.gif"/>
         <img src = "/images/xhtml.gif"/>
         <img src = "/images/wml_logo.gif"/>
         <img src = "/images/javascript.gif"/>
      </div>

      <div id = "droparea">
         Drag and Drop Your Images in this area
      </div>
   </body>
</html>

将产生以下结果 −

scriptaculous_drag_drop.htm
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