每次加载网页时,onchange 方法都会起作用,但每个值只能起作用一次。当选择夏季时,会添加类(class),当我选择冬季时,会添加类(class),但如果我再次选择夏季,它将不起作用。这是为什么?
const landingBGR = document.querySelector(".landing-wrapper");
const landingBTN = document.getElementById("l-btn");
function selectedSeason(season) {
switch(season) {
case "summer":
landingBTN.setAttribute("href","summer.html");
landingBGR.classList.add("summer-bgr");
break;
case "winter":
landingBTN.setAttribute("href","winter.html");
landingBGR.classList.add("winter-bgr");
break;
}
}
<select name="" id="landing-drop" onchange="oninput(this.value)">
<option value="">Ireland in the four Seasons</option>
<option value="summer">Summer</option>
<option value="winter">Winter</option>
</select>
最佳答案
当您选择新选项时,尝试删除旧类。
landingBGR.classList.remove("summer-bgr");
landingBGR.classList.remove("winter-bgr");
你可能需要
if(landingBGR.classList.contains("classname"))
关于javascript - 为什么 onChange 每个值只工作一次,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55534049/