Question

我试图编写一个简单的条件语句来检查一个元素的ID，以便在被放到另一个元素上时识别它并且有什么东西让我失望......这里是JSFiddle：{{ 3}}

HTML：

<div class="droppable" id="drop1">Drop region 1</div>
<div class="droppable" id="drop2">Drop region 2</div>

<div class="draggable" id="drag1">Drag 1</div>
<div class="draggable" id="drag2">Drag 2</div>

jQuery的：

$( "#drag1" ).draggable();
$( "#drag2" ).draggable();

$( "#drop1" ).droppable({
  drop: function() {
    if ($(this).attr("id") == "drag1") {
        alert("drag1 was dropped on drop1");
      } else {
      alert("something else was dropped on drop1");
      }
    }
});
$( "#drop2" ).droppable({
  drop: function() {
    alert( "dropped on drop2" );
  }
});

当＃drag1或＃drag2在＃drop1上被删除时，它会运行else {} ...

Answer 1

在drop event callback内，this引用了droppable元素（在本例中为#drop1），这就是if条件语句未按预期工作的原因

要获取已删除元素的id，请使用drop event callback中的ui.draggable访问该元素：

Example Here

$("#drop1").droppable({
    drop: function (event, ui) {
        if (ui.draggable.attr("id") === "drag1") {
            // ...
        }
    }
});

jQuery if语句没有捕获#ID

1 个答案: