use*_*977 11 html javascript global onclick button
我希望Button每次点击它都会改变颜色.但它只会在第一次点击时改变颜色.
我相信问题在于setColor功能.每次我点击时Button,count都会设置为1.所以即使我将其设置为0,它也会在下次点击时重置为1.我该如何解决？javascript/html中是否有全局变量可以轻松解决？
<!DOCTYPE html>
<html>
<head>
<script>
function setColor(btn, color){
var count=1;
var property = document.getElementById(btn);
if (count == 0){
property.style.backgroundColor = "#FFFFFF"
count=1;
}
else{
property.style.backgroundColor = "#7FFF00"
count=0;
}
}
</script>
</head>
<body>
<input type="button" id="button" value = "button" style= "color:white" onclick="setColor('button', '#101010')";/>
</body>
</html>
Jul*_*n P 10
javascript中确实存在全局变量.您可以了解有关范围的更多信息,这在这种情况下很有帮助.
您的代码可能如下所示:
<script>
var count = 1;
function setColor(btn, color) {
var property = document.getElementById(btn);
if (count == 0) {
property.style.backgroundColor = "#FFFFFF"
count = 1;
}
else {
property.style.backgroundColor = "#7FFF00"
count = 0;
}
}
</script>
希望这可以帮助.
1.
function setColor(e) {
var target = e.target,
count = +target.dataset.count;
target.style.backgroundColor = count === 1 ? "#7FFF00" : '#FFFFFF';
target.dataset.count = count === 1 ? 0 : 1;
/*
() : ? - this is conditional (ternary) operator - equals
if (count === 1) {
target.style.backgroundColor = "#7FFF00";
target.dataset.count = 0;
} else {
target.style.backgroundColor = "#FFFFFF";
target.dataset.count = 1;
}
target.dataset - return all "data attributes" for current element,
in the form of object,
and you don't need use global variable in order to save the state 0 or 1
*/
}
<input
type="button"
id="button"
value="button"
style="color:white"
onclick="setColor(event)";
data-count="1"
/>
2.
function setColor(e) {
var target = e.target,
status = e.target.classList.contains('active');
e.target.classList.add(status ? 'inactive' : 'active');
e.target.classList.remove(status ? 'active' : 'inactive');
}
.active {
background-color: #7FFF00;
}
.inactive {
background-color: #FFFFFF;
}
<input
type="button"
id="button"
value="button"
style="color:white"
onclick="setColor(event)"
/>