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HTML ondrop事件用法及代码示例


当将可拖动元素拖放到有效放置目标上时，将发生HTML DOM ondrop事件。

在拖放操作的不同阶段中使用并发生了一些事件：

    在可拖动目标上触发的事件：
  • ondragstart:开始拖动元素时发生。
  • ondrag:在元素拖动时发生。
  • ondragend:元素拖动完成时发生。
    在投放目标上触发的事件：
  • ondragenter:当拖动的元素进入放置目标时发生。
  • ondragover:当拖动的元素在放置目标上方时发生。
  • ondragleave:当拖动的元素从放置目标离开时发生。
  • ondrop:当拖动的元素放置在放置目标上时发生。

用法:

  • 在HTML中： 
    <element ondrop="myScript">
  • 在JavaScript中： 
    object.ondrop = function(){myScript};
  • 在JavaScript中，使用addEventListener()方法： 
    object.addEventListener("drop", myScript);

注意：链接和图像默认是可拖动的。

范例1：

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <title>HTML DOM ondrop Event</title> 
    <style> 
        .droptarget { 
            float:center; 
            width:300px; 
            height:50px; 
            margin:20px; 
            padding:5px; 
            border:6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2>HTML DOM ondrop Event</h2> 
  
        <div class="droptarget" 
             ondrop="dropEle(event)" 
             ondragover="allowDropEle(event)"> 
  
            <p ondragstart="dragStartEle(event)"
               draggable="true" 
               id="dragtarget"> 
                Dragable element 
            </p> 
  
        </div> 
  
        <div class="droptarget" 
             ondrop="dropEle(event)" 
             ondragover="allowDropEle(event)"> 
        </div> 
  
        <p id="demo"></p> 
  
        <script> 
            function dragStartEle(event) { 
                event.dataTransfer.setData( 
                  "Text", event.target.id); 
                
                document.getElementById( 
                  "demo").innerHTML = "Dragging starts"; 
            } 
  
            function allowDropEle(event) { 
                event.preventDefault(); 
            } 
  
            function dropEle(event) { 
                event.preventDefault(); 
                var data =  
                    event.dataTransfer.getData("Text"); 
                
                event.target.appendChild( 
                  document.getElementById(data)); 
                
                document.getElementById("demo").innerHTML =  
                  "Element dropped"; 
            } 
        </script> 
    </center> 
  
</body> 
  
</html>

输出：

范例2：

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <title> 
        HTML DOM ondrop Event 
    </title> 
    <style> 
        .droptarget { 
            float:center; 
            width:300px; 
            height:50px; 
            margin:20px; 
            padding:5px; 
            border:6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2>HTML DOM ondrop Event</h2> 
  
        <div class="droptarget"> 
            <p draggable="true" 
               id="dragtarget"> 
                Dragable element 
          </p> 
        </div> 
  
        <div class="droptarget"> 
      </div> 
  
        <p id="demo"></p> 
  
        <script> 
            // Event fired on the drag target  
            document.ondragstart = function(event) { 
                event.dataTransfer.setData("Text", event.target.id); 
                document.getElementById("demo").innerHTML = "Dragging starts"; 
            }; 
  
            // Events fired on the drop target  
            document.ondragover = function(event) { 
                event.preventDefault(); 
            }; 
  
            document.ondrop = function(event) { 
                event.preventDefault(); 
                var data = event.dataTransfer.getData("Text"); 
                event.target.appendChild(document.getElementById(data)); 
                document.getElementById("demo").innerHTML = "Element dropped"; 
            }; 
        </script> 
    </center> 
</body> 
  
</html>

输出：

范例3：

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <title>HTML DOM ondrop Event</title> 
    <style> 
        .droptarget { 
            float:center; 
            width:300px; 
            height:50px; 
            margin:20px; 
            padding:5px; 
            border:6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2>HTML DOM ondrop Event</h2> 
  
        <div class="droptarget"> 
            <p draggable="true" id="dragtarget"> 
              Dragable element</p> 
        </div> 
  
        <div class="droptarget"></div> 
  
        <p id="demo"></p> 
  
        <script> 
            // Event fired on the drag target  
            document.addEventListener("dragstart", function(event) { 
                event.dataTransfer.setData("Text", event.target.id); 
                document.getElementById("demo").innerHTML = "Dragging starts"; 
            }); 
  
            // Events fired on the drop target  
            document.addEventListener("dragover", function(event) { 
                event.preventDefault(); 
            }); 
  
            document.addEventListener("drop", function(event) { 
                event.preventDefault(); 
                var data = event.dataTransfer.getData("Text"); 
                event.target.appendChild(document.getElementById(data)); 
                document.getElementById("demo").innerHTML = "Element dropped"; 
            }); 
        </script> 
    </center> 
  
</body> 
  
</html>

输出：

支持的浏览器：下面列出了HTML DOM ondrop Event支持的浏览器：

  • 谷歌浏览器
  • IE浏览器
  • Firefox
  • 苹果Safari
  • Opera


相关用法


注：本文由纯净天空筛选整理自Vijay Sirra大神的英文原创作品 HTML | DOM ondrop Event。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。