In HTML, any element can be dragged and dropped.
Drag the 91xjr image into the rectangle.
Drag and drop is a very common feature. It is when you "grab" an object and drag it to a different location.
The numbers in the table specify the first browser version that fully supports Drag and Drop.
API | |||||
---|---|---|---|---|---|
Drag and Drop | 4.0 | 9.0 | 3.5 | 6.0 | 12.0 |
The example below is a simple drag and drop example:
<!DOCTYPE HTML>
<html>
<head>
<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)"></div>
<img id="drag1" src="img_logo.gif" draggable="true" ondragstart="drag(event)" width="336" height="69">
</body>
</html>
Try it Yourself »
It might seem complicated, but lets go through all the different parts of a drag and drop event.
First of all: To make an element draggable, set the draggable
attribute to true:
<img draggable="true">
Then, specify what should happen when the element is dragged.
In the example above, the ondragstart
attribute calls a function, drag(event), that specifies what data to be dragged.
The dataTransfer.setData()
method sets the data type and the value of the dragged data:
function drag(ev) {
ev.dataTransfer.setData("text", ev.target.id);
}
In this case, the data type is "text" and the value is the id of the draggable element ("drag1").
The ondragover
event specifies where the dragged data can be dropped.
By default, data/elements cannot be dropped in other elements. To allow a drop, we must prevent the default handling of the element.
This is done by calling the event.preventDefault()
method for the ondragover event:
event.preventDefault()
When the dragged data is dropped, a drop event occurs.
In the example above, the ondrop attribute calls a function, drop(event):
function drop(ev) {
ev.preventDefault();
var data = ev.dataTransfer.getData("text");
ev.target.appendChild(document.getElementById(data));
}
Code explained:
How to drag (and drop) an image back and forth between two <div> elements:
截取页面反馈部分,让我们更快修复内容!也可以直接跳过填写反馈内容!