Html5案例：实现文字和图片的拖放

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案例1 文字的拖放

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>dragdrop</title>
<style>
body,div,p{margin:0;padding:0}
#dragtarget,#demo,#droptarget
{
    width: 200px; 
    height: 35px;

    text-align:center;
    padding: 10px;
}
#droptarget
{
    margin-top:10px;
    border:2px solid #000;
}
#demo
{
     font-size:12px;color:#090
}
</style>
<script>
function dragStart(event) 
{
    event.dataTransfer.setData("Text", event.target.id);
    document.getElementById("demo").innerHTML = "开始拖动";
}
function allowDrop(event) 
{
    event.preventDefault();
    event.target.style.border="1px dotted #900";
    document.getElementById("demo").innerHTML="进入目标范围";
}
function drop(event) 
{
    event.preventDefault();
    var data=event.dataTransfer.getData("Text");
    event.target.appendChild(document.getElementById(data));
    document.getElementById("demo").innerHTML="放置";
}

</script>
</head>
<body>
<div draggable="true" id="dragtarget" ondragstart="dragStart(event)">将文本拖入矩形框</div>
<div id="droptarget" ondragover="allowDrop(event)" ondrop="drop(event)" ></div>
<div id="demo"></div>
</body>
</html>

案例2 图片的拖放

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> 
<title>dragdrop</title>
<style type="text/css">
#div1, #div2
{float:left; width:322px; height:204px; margin:10px;padding:10px;border:1px solid #aaaaaa;}
</style>
<script>
function allowDrop(ev)
{
   ev.preventDefault();
}

function drag(ev)
{
   ev.dataTransfer.setData("Text",ev.target.id);
}

function drop(ev)
{
   ev.preventDefault();
   var data=ev.dataTransfer.getData("Text");
   ev.target.appendChild(document.getElementById(data));
}
</script>
</head>
<body>
<div id="div1" ondrop="drop(event)" ondragover="allowDrop(event)">
      <img src="images/solution.png" draggable="true" ondragstart="drag(event)" id="drag1" width="310" height="200">
</div>
<div id="div2" ondrop="drop(event)" ondragover="allowDrop(event)"></div>
</body>
</html>

案例3 图片的拖放

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"> 
<title>dragdrop</title>
<style type="text/css">
.droptarget
{
float:left; 
width:322px; 
height:204px; 
margin:10px;
padding:10px;
border:1px solid #aaaaaa;
}
p{clear:both}
</style>
</head>
<body>

<div  class="droptarget">
      <img src="images/solution.png" draggable="true"  id="dragtarget" width="310" height="200">
</div>
<div  class="droptarget"></div>
<p id="demo"></p>

<script>
/* 拖动时触发*/
document.addEventListener("dragstart", function(event) {
    //dataTransfer.setData()方法设置数据类型和拖动的数据
    event.dataTransfer.setData("Text", event.target.id);
    // 拖动 p 元素时输出一些文本
    document.getElementById("demo").innerHTML="开始拖动图片";    
    //修改拖动元素的透明度
    event.target.style.opacity = "0.4";
});
//在拖动p元素的同时,改变输出文本的颜色
document.addEventListener("drag", function(event) {
    document.getElementById("demo").style.color = "red";
});
// 当拖完p元素输出一些文本元素和重置透明度
document.addEventListener("dragend", function(event) {
    document.getElementById("demo").innerHTML = "完成图片拖动";
    event.target.style.opacity = "1";
});
/* 拖动完成后触发 */
// 当p元素完成拖动进入droptarget,改变div的边框样式
document.addEventListener("dragenter", function(event) {
    if ( event.target.className == "droptarget" ) {
        event.target.style.border = "3px solid red";
    document.getElementById("demo").innerHTML = "进入目标";
    }
});
// 默认情况下,数据/元素不能在其他元素中被拖放。对于drop我们必须防止元素的默认处理
document.addEventListener("dragover", function(event) {
    event.preventDefault();
});
// 当可拖放的p元素离开droptarget，重置div的边框样式
document.addEventListener("dragleave", function(event) {
    if ( event.target.className == "droptarget" ) {
        event.target.style.border = "";
    document.getElementById("demo").innerHTML = "离开源";
    }
});
/*对于drop,防止浏览器的默认处理数据(在drop中链接是默认打开)
复位输出文本的颜色和DIV的边框颜色
利用dataTransfer.getData()方法获得拖放数据
拖拖的数据元素id(“drag1”)
拖拽元素附加到drop元素*/
document.addEventListener("drop", function(event) {
    event.preventDefault();
    if ( event.target.className == "droptarget" ) {
        document.getElementById("demo").style.color = "";
        event.target.style.border = "";
        var data = event.dataTransfer.getData("Text");
        event.target.appendChild(document.getElementById(data));
    }
});
</script>
</body>
</html>
取自“http://www.openbrains.net/mediawiki/index.php?title=Html5案例：实现文字和图片的拖放&oldid=16123”