这似乎是一个简单的问题,但没有什么可以解决的。我正在尝试使用 javascript/jQuery 动态更改某些文本的背景颜色(从白色或粉红色到绿色),但由于某种原因它不起作用。文本使用名为“.novice”的 CSS 类设置样式。
这是 CSS。这很简单。我还尝试完全删除背景颜色,因此它还没有设置背景颜色。
<style type="text/css">
.novice {
background-color: pink;
}
</style>
这是一个数组,其中包含我使用循环写出的元素。第一项具有“新手”类
var achievements = ['<span class="novice">novice - 10 or more guesses </span>', ...]
下面是一个 if 语句,如果该语句为真,则应该使“.novice”类具有“background-color: green”属性,并使“novice - 10 次或更多次猜测”以绿色突出显示。我确信我已经正确设置了变量 timeguessed 并且拼写正确。但是当 timeguessed 大于 10 时,“新手...”仍然不会以绿色突出显示。
if (timesguessed > 10) {
$('.novice').css('background-color', 'green');
}
我上面的部分输入正确吗? 我也试过替换 $('.novice').css('background-color', 'green');和 $('.novice').background-color(green); ,尽管这可能是错误的。
即使我用所谓的新修改的“新手”类打印出另一行,文本仍然不会以绿色突出显示。
document.write('<span class="novice">novice - 10 or more guesses </span>');
我知道原来的 CSS .novice 类是有效的,因为无论 timeguessed 大于还是小于 10,文本都会以粉红色突出显示。
我不确定是 Javascript 没有修改 CSS 类还是什么。或者它只是做了其他事情来覆盖它?
感谢您的帮助。是的,我是 javascript/jQuery 的初学者。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
.novice {
}
</style>
<script type="text/javascript" src="../MM_JAVASCRIPT2E/MM_JAVASCRIPT2E/_js/jquery-1.6.3.min.js"></script>
<title>Number Guessing Game</title>
</head>
<body>
<h1 style="text-align:center;"> Number Game </br> Try to guess my number that is between 0-1000 </h1>
<script>
// BEGIN LONG BLOCK OF CODE WITH GUESSING GAME MECHANISMS. You can ignore this part I think, this part works.
var realnumber = prompt('Player 1, please enter a number for Player 2 to guess then hand it off to Player 2.', '');
while (isNaN(realnumber)) {
realnumber = prompt('Player 1, please enter a NUMBER, dimwit, for Player 2 to guess.', '');}
var timesguessed=0;
while (numbertoguess != 0) {
var numbertoguess = prompt("Player 2, guess a number", "");
while (isNaN(numbertoguess)) {
numbertoguess = prompt('Please, type in a number');} // why don't I need an "else" here?
numbertoguess = Math.abs(numbertoguess - realnumber);
if ( numbertoguess >= 50 ) {
alert("Tundra cold");
timesguessed++;
}
else if ( 30 <= numbertoguess && numbertoguess < 50) {
alert("cold");
timesguessed++;
}
else if ( 20 <= numbertoguess && numbertoguess < 30 ) {
alert("warm");
timesguessed++;
}
else if ( 10 <= numbertoguess && numbertoguess< 20 ) {
alert("hot");
timesguessed++;
}
else if ( 5 <= numbertoguess && numbertoguess < 10 ) {
alert("Steaming hot!");
timesguessed++;
}
else if ( 3 <= numbertoguess && numbertoguess < 5 ) {
alert("SCALDING HOT!");
timesguessed++;
}
else if ( 1 < numbertoguess && numbertoguess < 3 ) {
alert("FIRE!");
timesguessed++;
}
else if ( numbertoguess == 1 ) {
alert("Face Melting!");
timesguessed++;
} else if ( numbertoguess == 0 ) {
alert("BINGO!");
timesguessed++;
}
}
document.write('</br></br></br></br><h2 style="text-align:center; font-size: 18px;"> The number was ' + realnumber + '.');
if (timesguessed == 1) {
document.write('</span><h2 style="text-align:center;">It took you ' + timesguessed + ' guess.</h2>');
} else {
document.write('<h2 style="text-align:center;">It took you ' + timesguessed + ' guesses.</h2>');
}
// END LONG BLOCK OF CODE WITH GUESSING GAME MECHANISMS
document.write('</br></br>')
//below is the array written out with a loop
var achievements = ['<span class="novice">novice - 10 or more guesses </span>',bronze - 7-10 guesses', 'silver', 'gold', 'titanium', 'platinum', 'diamond', ]
var counter = 0;
while (counter < achievements.length) {
document.write('<h2 style="text-align:center;">' + achievements[counter] + ' ');
counter++;
}
//below is the "if" function of question
if (timesguessed > 10) {
$('.novice').css('background-color', '#00FF00'); //why does this not work?
}
document.write('<span class="novice">novice - 10 or more guesses </span>'); //why does this not work?
</script>
</body>
</html>
最佳答案
代码中的
.css()
通过向它们添加内联样式来更改页面上已存在的元素的样式 - 不是通过修改 css 规则。
您可以像这样在运行时添加新规则:
$('head').append('<style type="text/css">.novice{color:green;}</style>');
不过,我不支持此类修改。我更愿意看到这样的 css
.novice {background-color: pink;}
.over-ten-guesses .novice {background-color:green;}
之后,您可以在任何以 .novice
为后代的容器元素上使用 Javascript 切换 .over-ten-guesses
类。
关于javascript - 使用 javascript/jQuery 更改类的背景颜色属性,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/11337404/