使用 REDIPS 出色的拖放库，我一直在尝试找出为什么 droppedBefore 事件不触发。
我已经删减了简单的示例，并将文件上传到此处以方便重现:http://tempsend.com/8B0DF444D3，这里是一个实时片段，可以快速向您展示该问题。
"use strict";
// define redips_init variable
var redips = {}, // redips container
rd = REDIPS.drag, // reference to the REDIPS.drag library
msg;
// redips initialization
redips.init = function () {
msg = document.getElementById('message');
// how to display disabled elements
rd.style.borderDisabled = 'solid'; // border style for disabled element will not be changed (default is dotted)
rd.style.opacityDisabled = 60; // disabled elements will have opacity effect
// initialization
rd.init();
// only "smile" can be placed to the marked cell
//rd.mark.exception.d8 = 'smile';
// shift DIV elements with animation
rd.shift.animation = true;
// disabled elements will have opacity effect
rd.style.opacityDisabled = 50;
// set hover color
rd.hover.colorTd = '#9BB3DA';
// prepare handlers
rd.event.cloned = function () {
// display message
var pos = rd.getPosition();
msg.innerHTML += ' FROM ' + pos[1] + ' ' + pos[2] + '<br>'
};
rd.event.droppedBefore = function (targetCell) {
alert('THIS EVENT FIRED YAY@!!!!'); //<-- SHOW THIS TO WIN THE PRIZE!
};
rd.event.deleted = function (cloned) {
// if cloned element is directly moved to the trash
if (cloned) {
var pos = rd.getPosition();
msg.innerHTML += ' TO ' + pos[1] + ' ' + pos[2] + '<br>';
}
else {
msg.innerHTML += 'Deleted';
}
};
};
// add onload event listener
if (window.addEventListener) {
window.addEventListener('load', redips.init, false);
}
else if (window.attachEvent) {
window.attachEvent('onload', redips.init);
}/*
Darko Bunic
http://www.redips.net/
Jun, 2011.
*/
body {
font-family: arial;
margin: 0px; /* for IE6 / IE7 */
}
/* add bottom margin between tables */
#table1,
#table2 {
margin-bottom: 20px;
}
/* drag container */
#redips-drag {
margin: auto;
width: 680px;
}
/* set border for images inside DRAG region - exclude image margin inheritance */
/* my WordPress theme had some funny margin settings */
#redips-drag img {
margin: 1px;
}
/* drag objects (DIV inside table cells) */
.redips-drag {
cursor: move;
margin: auto;
margin-bottom: 1px;
margin-top: 1px;
z-index: 10;
background-color: white;
text-align: center;
font-size: 10pt; /* needed for cloned object */
width: 140px;
height: 150px; /* objects height */
line-height: 20px;
/* round corners */
border-radius: 4px; /* Opera, Chrome */
-moz-border-radius: 4px; /* FF */
}
/* drag objects border for the first table */
.t1 {
border: 2px solid #499B33;
}
/* drag object border for the second table */
.t2 {
border: 2px solid SteelBlue;
}
/* cloned objects - third table */
.t3 {
border: 2px solid #FF8A58;
}
/* allow / deny access to cells marked with 'mark' class name */
.redips-mark {
color: white;
background-color: #9B9EA2;
}
/* trash cell */
.redips-trash {
color: white;
background-color: #e0e0e0;
}
.icontext {
color: black;
}
/* tables */
div#redips-drag table {
background-color: #e0e0e0;
border-collapse: collapse;
}
/* input elements in dragging container */
div#redips-drag input {
cursor: auto;
}
/* height for input text in DIV element */
div#drag #d13 input {
height: 13px;
}
/* height for dropdown menu in DIV element */
div#drag #d5 select {
height: 20px;
}
/* table cells */
div#redips-drag td {
height: 32px;
border: 1px solid white;
text-align: center;
font-size: 10pt;
padding: 2px;
}
/* "Click" button */
.button {
margin-bottom: 2px;
background-color: #6A93D4;
color: white;
border-width: 1px;
width: 44px;
padding: 0px;
}
/* toggle checkboxes at the bottom */
.checkbox {
margin-left: 13px;
margin-right: 14px;
width: 13px; /* needed for IE ?! */
}
/* message cell */
.message_line {
padding-left: 10px;
margin-bottom: 3px;
font-size: 10pt;
color: #888;
}<!DOCTYPE html>
<html><head>
<meta name="description" content="Description">
<meta name="viewport" content="width=device-width, user-scalable=no"><!-- "position: fixed" fix for Android 2.2+ -->
<link rel="stylesheet" href="./dragDrop_files/12112015.css" type="text/css" media="screen">
<script type="text/javascript" src="http://www.redips.net/my/preview/REDIPS_drag/redips-drag-min.js"></script>
<script type="text/javascript" src="./dragDrop_files/script.js"></script>
<title>Droppable Event</title>
</head>
<body>
<div style="background-color:#eee;padding:10px;text-align:center;font-size:20px;font-weight:bold">A</div>
<br>
<div id="redips-drag">
<!-- tables inside this DIV could have draggable content -->
<div style="background-color:#eee;padding:10px;text-align:center;font-size:20px;font-weight:bold"><a href="">Drop Before Event Not Working</a></div>
<table id="FSU4">
<colgroup><col width="160"><col width="160"><col width="160"><col width="40"><col width="160"></colgroup>
<tbody><tr height="150px" style="background-color: #eee">
<td class="redips-trash" title="adsf"><div id="34563463" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">sdafsfd</a><BR></div></td>
<td class="redips-trash" title="ertrt"><div id="2765657" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">fghdfghH</a></div></td>
<td class="redips-trash" title="erter"><div id="3456347" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">ljkljhsdf</a></div></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
</tr>
<tr height="150px">
<td class="redips-mark"></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
</tr>
</tbody></table>
<div id="message" > </div>
<div><input type="button" value="Save1" class="button" onclick="save('plain')" title="Send content to the server (it will only show accepted parameters)"><span class="message_line">Save content of the first table (plain query string)</span></div>
<div><input type="button" value="Save2" class="button" onclick="save('json')" title="Send content to the server (it will only show accepted parameters)"><span class="message_line">Save content of the first table (JSON format)</span></div>
<div><input type="radio" name="drop_option" class="checkbox" onclick="setMode(this)" value="multiple" title="Enabled dropping to already taken table cells" checked="true"><span class="message_line">Enable dropping to already taken table cells</span></div>
<div><input type="radio" name="drop_option" class="checkbox" onclick="setMode(this)" value="single" title="Disabled dropping to already taken table cells"><span class="message_line">Disable dropping to already taken table cells</span></div>
<div><input type="radio" name="drop_option" class="checkbox" onclick="setMode(this)" value="switch" title="Switch content"><span class="message_line">Switch content</span></div>
<div><input type="radio" name="drop_option" class="checkbox" onclick="setMode(this)" value="switching" title="Switching content continuously"><span class="message_line">Switching content continuously</span></div>
<div><input type="radio" name="drop_option" class="checkbox" onclick="setMode(this)" value="overwrite" title="Overwrite content"><span class="message_line">Overwrite content</span></div>
<div><input type="checkbox" class="checkbox" onclick="toggleDeleteCloned(this)" title="Remove cloned object if dragged outside of any table" checked="true"><span class="message_line">Remove cloned element if dragged outside of any table</span></div>
<div><input type="checkbox" class="checkbox" onclick="toggleConfirm(this)" title="Confirm delete"><span class="message_line">Confirm delete</span></div>
<div><input type="checkbox" class="checkbox" onclick="toggleDragging(this)" title="Enable dragging" checked="true"><span class="message_line">Enable dragging</span></div>
<div id="redips_clone" style="height: 1px; width: 1px;"></div></div>
</body></html>要查看问题，请运行代码片段并将一个框拖到另一个框上，应显示一条警告:THIS EVENT FIRED YAY@!!!!
我从 http://www.redips.net/my/preview/REDIPS_drag/example26/ 中获取了上述代码，它有一个有效的 rd.event.droppedBefore 事件。我已经将我的缩减重现与示例进行了 10 次比较，但仍然无法确定为什么该事件没有被触发？另外 2 个事件 rd.event.cloned 和 rd.event.deleted 都可以工作。
最佳答案
由于此代码，它不起作用，
原始代码:
<tr height="150px" style="background-color: #eee">
<td class="redips-trash" title="adsf"><div id="34563463" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">sdafsfd</a><BR></div></td>
<td class="redips-trash" title="ertrt"><div id="2765657" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">fghdfghH</a></div></td>
<td class="redips-trash" title="erter"><div id="3456347" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">ljkljhsdf</a></div></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
固定代码:
<tr height="150px" style="background-color: #eee">
<td title="adsf"><div id="34563463" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">sdafsfd</a><BR></div></td>
<td title="ertrt"><div id="2765657" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">fghdfghH</a></div></td>
<td title="erter"><div id="3456347" class="redips-drag t3 redips-clone" style="border-style: solid; cursor: move;"><a href="http://abc.com.au" title="abc">ljkljhsdf</a></div></td>
<td class="redips-mark"></td>
<td class="redips-mark"></td>
原因很简单，要么你把 class="redips-drag Orange redips-clone"要么 class="redips-trash"都不给一个元素。你给了 td redips-trash ，里面给了 div redips-drag ，我认为这是一个困惑。根据示例链接，我发现了那个错误。如果您想确保它不会重复，请删除 redips-clone。
关于javascript - dropBefore 事件未按预期工作，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33666301/