Html代码:
<html><head><title>Controlling Styles with JavaScript</title><script language="javascript" type="text/javascript" src="style.js"></script>
</head><body>
<h1 id="head1">
Controlling Styles with JavaScript
</h1>
<hr>
<p id="p1">Select the color for paragraphs and headings using the form below. The colors you specified will be dynamically changed in this document. The Change occurs as soon as you change the value of either the drop-down lists in the form.</p>
<hr>
<h2 id="he2">This is the H2. So many thing I should to do. So many people I should to care. I want to be single. whenever i meet my real soulmate!</h2>
<form name="form1">
<b>Heading color:</b>
<select name="heading" onchange="changeColor('head1','heading');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
<br>
<b>Body text color:</b>
<select name="body" onchange="changeColor('p1','body');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
<br>
<b>H2 color:</b>
<select name="h2" onchange="changeColor('he2','h2');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
</form>
</html>
js代码:
// JavaScript Document
function changeColor(para1,para2)
{
i = document.form1.para2.selectedIndex;
chColor = document.form1.para2.options[i].value;
document.getElementById(para1).style.color = chColor;
}想通过改变下拉菜单的选择改变 相应文字段的颜色。不知道哪里出了问题!求教各位!
<html><head><title>Controlling Styles with JavaScript</title><script language="javascript" type="text/javascript" src="style.js"></script>
</head><body>
<h1 id="head1">
Controlling Styles with JavaScript
</h1>
<hr>
<p id="p1">Select the color for paragraphs and headings using the form below. The colors you specified will be dynamically changed in this document. The Change occurs as soon as you change the value of either the drop-down lists in the form.</p>
<hr>
<h2 id="he2">This is the H2. So many thing I should to do. So many people I should to care. I want to be single. whenever i meet my real soulmate!</h2>
<form name="form1">
<b>Heading color:</b>
<select name="heading" onchange="changeColor('head1','heading');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
<br>
<b>Body text color:</b>
<select name="body" onchange="changeColor('p1','body');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
<br>
<b>H2 color:</b>
<select name="h2" onchange="changeColor('he2','h2');">
<option value="black">Black</option>
<option value="red">Red</option>
<option value="blue">Blue</option>
<option value="green">Green</option>
<option value="yellow">Yellow</option>
</select>
</form>
</html>
js代码:
// JavaScript Document
function changeColor(para1,para2)
{
i = document.form1.para2.selectedIndex;
chColor = document.form1.para2.options[i].value;
document.getElementById(para1).style.color = chColor;
}想通过改变下拉菜单的选择改变 相应文字段的颜色。不知道哪里出了问题!求教各位!
function changeColor(para1,para2){
i=para2.selectedIndex;
chColor = para2.options[i].value;
alert(chColor);
document.getElementById(para1).style.color = chColor;
}
</script>
</head><body>
<h1 id="head1">
Controlling Styles with JavaScript
</h1>
<hr>
<p id="p1">Select the color for paragraphs and headings using the form below. The colors you specified will be dynamically changed in this document. The Change occurs as soon as you change the value of either the drop-down lists in the form. </p>
<hr>
<h2 id="he2">This is the H2. So many thing I should to do. So many people I should to care. I want to be single. whenever i meet my real soulmate! </h2>
<form name="form1">
<b>Heading color: </b>
<select name="heading" onchange="changeColor('head1',this);">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
<br>
<b>Body text color: </b>
<select name="body" onchange="changeColor('p1',this);">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
<br>
<b>H2 color: </b>
<select name="h2" onchange="changeColor('he2',this);">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
</form>
</html>
你哪种写法在:document.form1.para2就出错了
function changeColor(para1,para2)
{
i = document.form1[para2].selectedIndex;
chColor = document.form1[para2].options[i].value;
document.getElementById(para1).style.color = chColor;
}
</script>
</head> <body>
<h1 id="head1">
Controlling Styles with JavaScript
</h1>
<hr>
<p id="p1">Select the color for paragraphs and headings using the form below. The colors you specified will be dynamically changed in this document. The Change occurs as soon as you change the value of either the drop-down lists in the form. </p>
<hr>
<h2 id="he2">This is the H2. So many thing I should to do. So many people I should to care. I want to be single. whenever i meet my real soulmate! </h2>
<form name="form1">
<b>Heading color: </b>
<select name="heading" onchange="changeColor('head1','heading');">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
<br>
<b>Body text color: </b>
<select name="body" onchange="changeColor('p1','body');">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
<br>
<b>H2 color: </b>
<select name="h2" onchange="changeColor('he2','h2');">
<option value="black">Black </option>
<option value="red">Red </option>
<option value="blue">Blue </option>
<option value="green">Green </option>
<option value="yellow">Yellow </option>
</select>
</form>
</html>
<select name="h2" onchange="changeColor('he2','h2');">
还想请问下,为什么要用form1[para2]中的[para2]来表示呢?
from1[propertyName]访问from1中名为perpertyName这个变量的值的属性
如果你传的是对象的话 :参考2楼的写法,para2.selectedIndex