【发布时间】：2019-11-04 07:20:44
【问题描述】：
我有以下用于拖放应用程序的代码，它可以在桌面上按预期工作，但是当我想在移动设备上使用该应用程序时，拖动事件无法按预期工作。我知道触摸事件是必需的，但是我不确定如何设置它们并实现这些功能。
<style>
.objects {
display:inline-block;
background-color: #FFF3CC;
border: #DFBC6A 1px solid;
width: 50px;
height: 50px;
margin: 10px;
padding: 8px;
font-size: 18px;
text-align: center;
box-shadow: 2px 2px 2px #999;
cursor: move;
}
#drop_zone {
background-color: #EEE;
border: #999 1px solid;
width: 280px;
height: 200px;
padding: 8px;
font-size: 18px;
}
</style>
<h2 id="app_status">App status...</h2>
<h1>Drop Zone</h1>
<div id="drop_zone" ondragenter="drag_enter(event)" ondrop="drag_drop(event)" ondragover="return false" ondragleave="drag_leave(event)" ></div>
<div id="object1" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 1</div>
<div id="object2" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 2</div>
<div id="object3" class="objects" draggable="true" ondragstart="drag_start(event)" ondragend="drag_end(event)">object 3</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
<script>
function _(id){
return document.getElementById(id);
}
var droppedIn = false;
function drag_start(event) {
_('app_status').innerHTML = "Dragging the "+event.target.getAttribute('id');
event.dataTransfer.dropEffect = "move";
event.dataTransfer.setData("text", event.target.getAttribute('id') );
}
function drag_enter(event) {
_('app_status').innerHTML = "You are dragging over the "+event.target.getAttribute('id');
}
function drag_leave(event) {
_('app_status').innerHTML = "You left the "+event.target.getAttribute('id');
}
function drag_drop(event) {
event.preventDefault(); /* Prevent undesirable default behavior while dropping */
var elem_id = event.dataTransfer.getData("text");
_('app_status').innerHTML = "Dropped "+elem_id+" into the "+event.target.getAttribute('id');
droppedIn = true;
// Create our XMLHttpRequest object
var hr = new XMLHttpRequest();
// Create some variables we need to send to our PHP file
var url = "jqueryserver.php";
var vars = "value= "+elem_id;
hr.open("POST", url, true);
// Set content type header information for sending url encoded variables in the request
hr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
// Access the onreadystatechange event for the XMLHttpRequest object
hr.onreadystatechange = function() {
if(hr.readyState == 4 && hr.status == 200) {
var return_data = hr.responseText;
document.getElementById("app_status").innerHTML = return_data;
}
}
// Send the data to PHP now... and wait for response to update the status div
hr.send(vars); // Actually execute the request
document.getElementById("app_status").innerHTML = event.target.getAttribute('id')+"processing...";
}
function drag_end(event) {
if(droppedIn == false){
_('app_status').innerHTML = "You let the "+event.target.getAttribute('id')+" go.";
}
droppedIn = false;
}
</script>
【问题讨论】：
-
HammerJs 可能是一个不错的起点。这是一个简单且轻量级的库，可在您的网络应用中添加拖动和触摸事件支持。
-
我希望避免使用库，并获得类似于stackoverflow.com/questions/1517924/…中提出的解决方案
标签： javascript drag-and-drop touch-event