如何在 javascript 附加字段上使用可拖动？

Question

我正在使用 Jquery 可拖动来创建创建输入的应用程序的一部分，输入必须是可拖动的，在下面的项目（jsfiddle）中，您会看到只有创建的字段不可拖动，但一个直接加在html里的作品为什么？

https://jsfiddle.net/vtsjwb63/

html：

<div class="input_fields_wrap">
    <button class="add_field_button">Add More Fields</button>

    <div class="draggable ui-widget-content">
         <input type="text" name="mytext[]"/>
         <a href="#" class="remove_field">x</a>
    </div>
</div>

javascript：

$(document).ready(function() {
    var max_fields      = 10; //maximum input boxes allowed
    var wrapper         = $(".input_fields_wrap"); //Fields wrapper
    var add_button      = $(".add_field_button"); //Add button ID

    var x = 1; //initlal text box count
    $(add_button).click(function(e){ //on add input button click
        e.preventDefault();
        if(x < max_fields){ //max input box allowed
            x++; //text box increment
            $(wrapper).append(''
            + '<div class="draggable ui-widget-content added">'
            + '<p>not draggable anymore, why ?</p>'
            + '<input type="text" name="mytext[]"/>'
            + '<a href="#" class="remove_field">x</a>'
            + '</div>'
            ); //add input box
        }
    });

    $(wrapper).on("click",".remove_field", function(e){ //user click on remove text
        e.preventDefault(); $(this).parent('div').remove(); x--;
    })
    $( ".draggable" ).draggable({ grid: [ 5, 5 ], snap: true });
});

我该如何解决这个问题？

Answer 1

问题是因为您仅在页面加载时在 DOM 中的元素上实例化 draggable()。要使新元素可拖动，您需要在将它们附加到 DOM 后对它们调用 draggable。试试这个：

var max_fields = 10; // maximum input boxes allowed
var wrapper = $(".input_fields_wrap"); 
var add_button = $(".add_field_button");
var draggableOptions = { grid: [ 5, 5 ], snap: true }   

$(add_button).click(function(e) {
  e.preventDefault();
  if (wrapper.find('.draggable').length < max_fields) {
    $('<div class="draggable ui-widget-content added">'
      + '<p>not draggable anymore, why ?</p>'
      + '<input type="text" name="mytext[]"/>'
      + '<a href="#" class="remove_field">x</a>'
      + '</div>').appendTo(wrapper).draggable(draggableOptions); // < important change here
  }
});

$(wrapper).on("click", ".remove_field", function(e) {
  e.preventDefault();  
  $(this).parent('div').remove();
})
$(".draggable").draggable(draggableOptions);

Working example

Answer 2

您需要做的就是将点击事件与可拖动事件相关联。

 $(document).ready(function() {
        var max_fields      = 10; //maximum input boxes allowed
        var wrapper         = $(".input_fields_wrap"); //Fields wrapper
        var add_button      = $(".add_field_button"); //Add button ID
       
        var x = 1; //initlal text box count
        $(add_button).click(function(e){ //on add input button click
            e.preventDefault();
            if(x < max_fields){ //max input box allowed
                x++; //text box increment
                $(wrapper).append(''
                + '<div class="draggable ui-widget-content added">'
                + '<p>not draggable anymore, why ?</p>'
                + '<input type="text" name="mytext[]"/>'
                + '<a href="#" class="remove_field">x</a>'
                + '</div>'
                ); //add input box
            }
        });
       
        $(wrapper).on("click",".remove_field", function(e){ //user click on remove text
            e.preventDefault(); $(this).parent('div').remove(); x--;
        })
        
        $('.add_field_button').click(function(){ 
        $( ".draggable" ).draggable({ grid: [ 5, 5 ], snap: true });
    });
    })

.draggable {padding:30px; background:red; width:200px; cursor:pointer;}
.added {background:yellow;}
   

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script
  src="https://code.jquery.com/ui/1.12.0/jquery-ui.js"
  integrity="sha256-0YPKAwZP7Mp3ALMRVB2i8GXeEndvCq3eSl/WsAl1Ryk="
  crossorigin="anonymous"></script>
<div class="input_fields_wrap">
    <button class="add_field_button">Add More Fields</button>
            <div class="draggable ui-widget-content">
            <input type="text" name="mytext[]"/>
            <a href="#" class="remove_field">x</a>
            </div>
</div>