这是来自 Lynda.com 的类(class)“Jquery Essentianl Training”,其中一个解决方案中有一点我实在无法理解。 任务是创建复选框,并根据是否选中来显示和隐藏具有特定数据属性的项目。
document.querySelector('#vitamincheck').addEventListener('change',function (evt) {
updateProductView("vitamins", evt.target.checked);
});
document.querySelector('#mineralcheck').addEventListener('change',function (evt) {
updateProductView("mineralwater", evt.target.checked);
});
document.querySelector('#proteincheck').addEventListener('change',function (evt) {
updateProductView("proteinbar", evt.target.checked);
});
function updateProductView(categoryName, visibility) {
var dataSelectorVal = "";
switch (categoryName) {
case "vitamins":
dataSelectorVal = "h2[data-type='vitamin']";
break;
case "mineralwater":
dataSelectorVal = "h2[data-type='mineralwater']";
break;
case "proteinbar":
dataSelectorVal = "h2[data-type='proteinbar']";
break;
}
$(".product-item").has(dataSelectorVal).css('display', visibility ? "" : "none");
}
我能理解它为什么有效。 但问题是当我尝试将 document.querySelector('#someid') 更改为 $('#someid') 或 document.getElementById('#someid'), 它不起作用。
我已经用谷歌搜索了很多,如果我指向某个 ID,docuemnt.querySelector 和 $() 的行为应该相同。 我在这里错过了什么吗?
或者如果它是复选框,则只能通过 document.querySelector 选择它?
顺便说一句,与上述 javascript 相关的 HTML 位如下。
<p>SHOW: <input type="checkbox" id="vitamincheck" value="vitamin" checked="checked"> Vitamins
<input type="checkbox" id="mineralcheck" value="mineralwater" checked="checked"> Mineral Water
<input type="checkbox" id="proteincheck" value="proteinbar" checked="checked"> Protein Bar</p>
<ul class="product-list">
<li class="product-item" data-prod_id="V-A1037">
<img class="product-image" src="images/products/vitamin-a.jpg" alt="Vitamin A - Product Photo">
<h2 class="product-name" data-type="vitamin">Vitamin A</h2>
</li>
<li class="product-item" data-prod_id="V-BC2178">
<img class="product-image" src="images/products/vitamin-bcomplex.jpg" alt="B Complex - Product Photo">
<h2 class="product-name" data-type="vitamin">Vitamin-B Complex</h2>
</li>
<li class="product-item" data-prod_id="MW-8812">
<img class="product-image" src="images/products/mineralwater-blueberry.jpg" alt="Blueberry Mineral Water - Product Photo">
<h2 class="product-name" data-type="mineralwater">Blueberry Mineral Water</h2>
</li>
<li class="product-item" data-prod_id="V-C6614">
<img class="product-image" src="images/products/vitamin-c.jpg" alt="Vitamin C - Product Photo">
<h2 class="product-name" data-type="vitamin">Vitamin C</h2>
</li>
<li class="product-item" data-prod_id="PB-8154">
<img class="product-image" src="images/products/proteinbar-chocolate.jpg" alt="Protein Bar Chocolate - Product Photo">
<h2 class="product-name" data-type="proteinbar">Chocolate Protein Bar</h2>
</li>
<li class="product-item" data-prod_id="V-CA4543">
<img class="product-image" src="images/products/vitamin-calcium.jpg" alt="Vitamin Calcium - Product Photo">
<h2 class="product-name" data-type="vitamin">Calcium Vitamin</h2>
</li>
<li class="product-item" data-prod_id="V-D1825">
<img class="product-image" src="images/products/vitamin-d.jpg" alt="Vitamin D - Product Photo">
<h2 class="product-name" data-type="vitamin">Vitamin D</h2>
</li>
<li class="product-item" data-prod_id="V-F2225">
<img class="product-image" src="images/products/vitamin-flaxseed-oil.jpg" alt="Flaxseed Oil - Product Photo">
<h2 class="product-name" data-type="vitamin">Flaxseed Oil Vitamin</h2>
</li>
<li class="product-item" data-prod_id="V-I7456">
<img class="product-image" src="images/products/vitamin-iron.jpg" alt="Vitamin Iron - Product Photo">
<h2 class="product-name" data-type="vitamin">Iron Vitamin</h2>
</li>
<li class="product-item" data-prod_id="MW-9143">
<img class="product-image" src="images/products/mineralwater-lemonlime.jpg" alt="Mineral Water Lemon Lime - Product Photo">
<h2 class="product-name" data-type="mineralwater">Lemon Lime Mineral Water</h2>
</li>
<li class="product-item" data-prod_id="V-M0019">
<img class="product-image" src="images/products/vitamin-magnesium.jpg" alt="Vitamin Magnesium - Product Photo">
<h2 class="product-name" data-type="vitamin">Magnesium Vitamin</h2>
</li>
<li class="product-item" data-prod_id="V-MV7763">
<img class="product-image" src="images/products/vitamin-multi.jpg" alt="Vitamin Multivitamin - Product Photo">
<h2 class="product-name" data-type="vitamin">Multi-vitamin</h2>
</li>
<li class="product-item" data-prod_id="PB-1234">
<img class="product-image" src="images/products/proteinbar-peanutbutter.jpg" alt="Vitamin Protein Bar Peanut Butter - Product Photo">
<h2 class="product-name" data-type="proteinbar">Peanut Butter Protein Bar</h2>
</li>
<li class="product-item" data-prod_id="MW-S0987">
<img class="product-image" src="images/products/mineralwater-strawberry.jpg" alt="Mineral Water Strawberry - Product Photo">
<h2 class="product-name" data-type="mineralwater">Strawberry Mineral Water</h2>
</li>
<li class="product-item" data-prod_id="PB-1919">
<img class="product-image" src="images/products/proteinbar-lemon.jpg" alt="Protein Bar Lemon - Product Photo">
<h2 class="product-name" data-type="proteinbar">Lemon Protein Bar</h2>
</li>
<li class="product-item" data-prod_id="MW-O1980">
<img class="product-image" src="images/products/mineralwater-orange.jpg" alt="Mineral Water Orange - Product Photo">
<h2 class="product-name" data-type="mineralwater">Orange Mineral Water</h2>
</li>
<li class="product-item" data-prod_id="MW-P1968">
<img class="product-image" src="images/products/mineralwater-peach.jpg" alt="Mineral Water Peach - Product Photo">
<h2 class="product-name" data-type="mineralwater">Peach Mineral Water</h2>
</li>
<li class="product-item" data-prod_id="MW-R2003">
<img class="product-image" src="images/products/mineralwater-raspberry.jpg" alt="Mineral Water Raspberry - Product Photo">
<h2 class="product-name" data-type="mineralwater">Raspberry Mineral Water</h2>
</li>
</ul><!-- product-list -->
最佳答案
如果你想使用 jQuery,你应该使用 on
jQuery 方法添加事件监听器,而不是普通 JS 的 addEventListener
方法。只需更换
addEventListener
与 on
:
$('#vitamincheck').on('change', function (evt) {
updateProductView("vitamins", evt.target.checked);
});
$('#mineralcheck').on('change', function (evt) {
updateProductView("mineralwater", evt.target.checked);
});
$('#proteincheck').on('change', function (evt) {
updateProductView("proteinbar", evt.target.checked);
});
关于javascript - 为什么 querySelector 可以工作而 $() 或 document.getElementById 不能与复选框一起工作?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/42884499/