jquery - 如何在单击按钮时从选定列表框中删除多个选定值

Question

我是 JQuery 的新手。我已经编写了用于从选定列表框中添加和删除代码的代码。在这里，从不同的选择列表框中添加前三个值已经完成，但是我无法删除我添加的这三个值。 HTML:

    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
    <select class="form-control select-manage-category" size="5">
        <option>1</option>
        <option>2</option>
        <option>1</option>
        <option>2</option>
    </select>
</div>
<div>
    <select class="form-control select-manage-category1" size="5">
        <option>1</option>
        <option>2</option>
        <option>1</option>
        <option>2</option>
    </select>
</div>
<div>
    <select class="form-control select-manage-category2" size="5">
        <option>1</option>
        <option>2</option>
        <option>1</option>
        <option>2</option>
    </select>
</div>
<div>
    <p class="text-center color-red">You can add up to 20 categories</p>
</div>
<input id="add-category" name="add" type="button" value="Add Category">
<input id="remove-category" name="add" type="button" value="Remove Category">
<div>
    <select id="selected-lst-values" class="form-group percent-100" size="5"></select>
</div>
<button class="btn btn-md btn-radius pi-btn prodetails-btn" type="button"><strong>Save</strong> <span class="glyphicon glyphicon-menu-right right-arrow-head-icon"></span></button>

CSS:

.select-manage-category, .select-manage-category1, .select-manage-category2 {
    width: 100px;
    float: left;
    margin-right: 4px;
}

p {
    clear: left;
    text-align: center;
}

#selected-lst-values {
    width: 100%;
}   

JQuery:

$(document).ready(function () {
    var one = $('.select-manage-category').val();
    var two = $('.select-manage-category1').val();
    var three = $('.select-manage-category2').val();
    $('#add-category').click(function () {
        $(
            '.select-manage-category, .select-manage-category1, .select-manage-category2'
        ).each(function () {
            // $('#selected-lst-values').append($(this).val());
            $('#selected-lst-values').append('<option value="' + $(this).val() + '">' + $(this).val() + '</option>');
        });
    });
    $('#remove-category').click(function () {
        $('.select-manage-category, .select-manage-category1, .select-manage-category2').each(function () {
            $('#selected-lst-values')
                .find('option[value="' + $(this).val() + '"')
                .remove();
        });
    });
});

Working Fiddle

Answer 1

你太了!如果您检查控制台日志，您会看到 .find()找不到目标，因为您错过了右方括号。

你只需要:

.find('option[value="' + $(this).val() + '"]')

$(document).ready(function() {
  var one = $('.select-manage-category').val();
  var two = $('.select-manage-category1').val();
  var three = $('.select-manage-category2').val();
  $('#add-category').click(function() {
    $(
      '.select-manage-category, .select-manage-category1, .select-manage-category2'
    ).each(function() {
      // $('#selected-lst-values').append($(this).val());
      $('#selected-lst-values').append('<option value="' + $(this).val() + '">' + $(this).val() + '</option>');
    });
  });
  $('#remove-category').click(function() {
    $('.select-manage-category, .select-manage-category1, .select-manage-category2').each(function() {
      $('#selected-lst-values')
        .find('option[value="' + $(this).val() + '"]')
        .remove();
    });
  });
});

.select-manage-category,
.select-manage-category1,
.select-manage-category2 {
  width: 100px;
  float: left;
  margin-right: 4px;
}

p {
  clear: left;
  text-align: center;
}

#selected-lst-values {
  width: 100%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
  <select class="form-control select-manage-category" size="5">
    <option>1</option>
    <option>2</option>
  </select>
</div>
<div>
  <select class="form-control select-manage-category1" size="5">
    <option>1</option>
    <option>2</option>
  </select>
</div>
<div>
  <select class="form-control select-manage-category2" size="5">
    <option>1</option>
    <option>2</option>
  </select>
</div>
<div>
  <p class="text-center color-red">You can add up to 20 categories</p>
</div>
<input id="add-category" name="add" type="button" value="Add Category">
<input id="remove-category" name="add" type="button" value="Remove Category">
<div>
  <select id="selected-lst-values" class="form-group percent-100" size="5">
  </select>
</div>
<button class="btn btn-md btn-radius pi-btn prodetails-btn" type="button"><strong>Save</strong>
  <span class="glyphicon glyphicon-menu-right right-arrow-head-icon"></span>
</button>

我还创建了一个更新的工作 Fiddle here .

希望这有帮助:)

编辑:

要删除最后三个值，然后能够删除前 三个值直到所有值都消失，您需要使用 CSS 选择器 last-of-type :

var the_index = $(this).val() - 1;
$('#selected-lst-values').find('option:nth-last-of-type(' + the_index + ')').remove();

$(document).ready(function() {
	var one = $('.select-manage-category').val();
	var two = $('.select-manage-category1').val();
	var three = $('.select-manage-category2').val();
	$('#add-category').click(function() {
		$(
			'.select-manage-category, .select-manage-category1, .select-manage-category2'
		).each(function() {
			$('#selected-lst-values').append('<option value="' + $(this).val() + '">' + $(this).val() + '</option>');
		});
	});
	$('#remove-category').click(function() {
	    $('.select-manage-category, .select-manage-category1, .select-manage-category2').each(function() {
					var the_index = $(this).val() - 1;
	        $('#selected-lst-values')
	               .find('option:nth-last-of-type(' + the_index + ')')
	               .remove();
	    });
	});
});

.select-manage-category,.select-manage-category1,.select-manage-category2{
	width:100px;
	float:left;
	margin-right:4px;
}
p{clear:left;text-align:center;}

#selected-lst-values{
	width:100%;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div><select class="form-control select-manage-category" size="5">
    <option>1</option>
    <option>2</option>
</select></div>
<div><select class="form-control select-manage-category1" size="5">
    <option>1</option>
    <option>2</option>
		</select></div>
<div><select class="form-control select-manage-category2" size="5">
    <option>1</option>
    <option>2</option>
		</select>
		</div>
<div>
<p class="text-center color-red">You can add up to 20 categories</p></div>
<input id="add-category" name="add" type="button" value="Add Category">
<input id="remove-category" name="add" type="button" value="Remove Category">
<div><select id="selected-lst-values" class="form-group percent-100" size="5">
		</select></div>
<button class="btn btn-md btn-radius pi-btn prodetails-btn" type="button"><strong>Save</strong> 
    <span class="glyphicon glyphicon-menu-right right-arrow-head-icon"></span>
</button>

这基于删除 <select> 中的最后三个选项。单击按钮列出，并且一次添加三个，最后三个选项将是您刚刚添加的选项。

我已经更新了我的 fiddle 来展示这个 here .

请注意，如果您愿意，也可以使用 .find('option').remove(); 一次删除所有 类别.

希望这有帮助:)