javascript - Javascript每个循环都有暂停而不是暂停
问题描述
我试图让这个简单的脚本将关键字值附加到 div innerhtml。但我希望它在每次打印之间暂停。这是我到目前为止所得到的。现在,它只是一次转储所有内容而不会暂停,或者只打印数组中的最后一个元素。不知道我做错了什么。
var root_keywords = [
"Keyword 1",
"Keyword 2",
"Keyword 3",
"Keyword 4"
];
document.getElementById("genBtn").addEventListener("click", createKeywords);
var kwDiv = document.getElementById("output");
function createKeywords()
{
root_keywords.forEach(function(kw)
{
var OldContents = kwDiv.innerHTML;
var NewContents = OldContents + kw + "<br />";
doAppend( NewContents );
});
}
function doAppend(kw) {
var kwDiv = document.getElementById("output");
setTimeout(function() { kwDiv.innerHTML = kw }, 500);
}
#output{
padding:10px;
width: 200px;
height: 200px;
background-color:#000;
display:block;
color:#66a565;
}
<!DOCTYPE html>
<html>
<head>
<title>Keyword Generator</title>
</head>
<body>
<h1>This is a Heading</h1>
<button type="button" id="genBtn">Generate</button>
<div id="output"></div>
</body>
</html>
解决方案
将超时毫秒乘以您正在迭代的当前索引,否则每个超时都会立即激活:
var root_keywords = [
"Keyword 1",
"Keyword 2",
"Keyword 3",
"Keyword 4"
];
document.getElementById("genBtn").addEventListener("click", createKeywords);
var kwDiv = document.getElementById("output");
function createKeywords() {
root_keywords.forEach(function(kw, i) {
var OldContents = kwDiv.innerHTML;
var NewContents = OldContents + kw + "<br />";
doAppend(NewContents, i);
});
}
function doAppend(kw, i) {
var kwDiv = document.getElementById("output");
setTimeout(function() {
kwDiv.innerHTML = kw
}, 500 * i);
}
#output {
padding: 10px;
width: 200px;
height: 200px;
background-color: #000;
display: block;
color: #66a565;
}
<h1>This is a Heading</h1>
<button type="button" id="genBtn">Generate</button>
<div id="output"></div>