Javascript 如何设置一个div的动画，使其在单击时淡入或滑入 //获取模式 var modal=document.getElementById（'myModal'）； //获取打开模式对话框的按钮 var btn=document.getElementById（“myBtn”）； //获取关闭模态的元素 var span=document.getElementsByClassName（“关闭”）[0]； //当用户单击该按钮时，打开模式对话框 btn.onclick=函数（）{ modal.style.display=“块”； } //当用户单击（x）时，关闭模式对话框 span.onclick=函数（）{ modal.style.display=“无”； } //当用户单击模式之外的任何位置时，将其关闭 window.onclick=函数（事件）{ 如果（event.target==模态）{ modal.style.display=“无”； } }

我希望在不使用jquery的情况下为div添加一些动画，因为它是用于显示横幅的，我不希望使用库来增大整个文件的大小。应该很简单，但似乎无法使其正常工作。

如下更改代码：

    // Get the modal
    var modal = document.getElementById('myModal');

    // Get the button that opens the modal
    var btn = document.getElementById("myBtn");

    // Get the <span> element that closes the modal
    var span = document.getElementsByClassName("close")[0];

    // When the user clicks the button, open the modal 
    btn.onclick = function() {
        modal.style.display = "block";
    }

    // When the user clicks on <span> (x), close the modal
    span.onclick = function() {
        modal.style.display = "none";
    }

    // When the user clicks anywhere outside of the modal, close it
    window.onclick = function(event) {
        if (event.target == modal) {
            modal.style.display = "none";
        }
    }

关闭样式为：

// Get the modal
var modal = document.getElementById('myModal');

// Get the button that opens the modal
var btn = document.getElementById("myBtn");

// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];

// When the user clicks the button, open the modal 
btn.onclick = function() {
    modal.style.cssText = "visibility: visible;opacity: 1;transition: 0.3s";
}

// When the user clicks on <span> (x), close the modal
span.onclick = function() {
    modal.style.cssText = "visibility: hidden;opacity: 0;transition: 0.3s";
}

// When the user clicks anywhere outside of the modal, close it
window.onclick = function(event) {
    if (event.target == modal) {
        modal.style.display = "none";
    }
}

modal.style.cssText = "visibility: visible;opacity: 1;transition: 0.3s";

工作示例：

modal.style.cssText = "visibility: hidden;opacity: 0;transition: 0.3s";