How to use jQuery to implement the drag and drop function of div

1. Foreword

In front-end development, the drag-and-drop function is a very common interaction method, and the implementation method is relatively simple. It is often implemented through front-end frameworks such as jQuery. This article will introduce in detail how to use jQuery to implement the drag and drop function of divs.

2. Implementation steps

1. HTML structure

First of all, the corresponding structure needs to be established in HTML, that is, the dragging div element needs to be implemented. In general, it is recommended to use absolute positioning to position it in a smaller area.

<div>
    <div></div>
</div>

2. CSS Style

Secondly, set the style of the drag element through CSS, such as setting the width, height, background color, border and other attributes of the div.

.box {
    position: relative;
    width: 500px;
    height: 500px;
    background-color: #f2f2f2;
    border: 1px solid #dcdcdc;
}

.drag {
    position: absolute;
    width: 50px;
    height: 50px;
    background-color: #29b6f6;
    border-radius: 50%;
}

3. JS code

Finally, the drag function is implemented through jQuery or native JS code. The specific implementation steps are as follows:

(1) Bind the mouse press event, move event and mouse lift event to the drag element.

$('.drag').mousedown(function(e){
    // 鼠标按下时的事件
}).mousemove(function(e){
    // 鼠标移动时的事件
}).mouseup(function(e){
    // 鼠标抬起时的事件
});

(2) In the mouse press event, save the position of the currently dragged element and the position of the mouse.

var box = $(".box");
var drag = $(".drag");

// 拖动元素的位置
var dragX = drag.offset().left - box.offset().left;
var dragY = drag.offset().top - box.offset().top;

// 鼠标的位置
var mouseX = e.pageX;
var mouseY = e.pageY;

(3) In the mouse movement event, calculate the distance that the dragged element needs to move, and realize the dragging of the element by changing the left and top values ​​​​of the dragged element.

var moveX = e.pageX - mouseX;
var moveY = e.pageY - mouseY;

drag.css({
    left: dragX + moveX + "px",
    top: dragY + moveY + "px"
});

(4) In the mouse lift event, clear the saved mouse position and dragged element position.

mouseX = 0;
mouseY = 0;
dragX = 0;
dragY = 0;

3. Complete code

nbsp;html>


    <title>jQuery拖动实例</title>
    <meta>
    <style>
        .box {
            position: relative;
            width: 500px;
            height: 500px;
            background-color: #f2f2f2;
            border: 1px solid #dcdcdc;
        }

        .drag {
            position: absolute;
            width: 50px;
            height: 50px;
            background-color: #29b6f6;
            border-radius: 50%;
        }
    </style>


    <div>
        <div></div>
    </div>
    <script></script>
    <script>
        var box = $(".box");
        var drag = $(".drag");
        var dragX = 0;
        var dragY = 0;
        var mouseX = 0;
        var mouseY = 0;

        drag.mousedown(function(e){
            dragX = drag.offset().left - box.offset().left;
            dragY = drag.offset().top - box.offset().top;
            mouseX = e.pageX;
            mouseY = e.pageY;
        }).mousemove(function(e){
            if(mouseX === 0 || mouseY === 0 || dragX === 0 || dragY === 0) {
                return;
            }
            
            var moveX = e.pageX - mouseX;
            var moveY = e.pageY - mouseY;

            drag.css({
                left: dragX + moveX + "px",
                top: dragY + moveY + "px"
            });
        }).mouseup(function(e){
            mouseX = 0;
            mouseY = 0;
            dragX = 0;
            dragY = 0;
        });
    </script>

4. Summary

This article mainly introduces how to use jQuery to realize the dragging function of div elements, through the interaction of HTML, CSS and JS Together, this interactive effect is achieved simply and easily. I hope it will be helpful to front-end developers.

The above is the detailed content of How to use jQuery to implement the drag and drop function of div. For more information, please follow other related articles on the PHP Chinese website!