问题
I am hoping to find a resource for lining up input elements in a HTML page. I find it difficult to get a select element and a text box to be the same width even when using the width style attribute, and it is even more difficult across browsers. Finally, file inputs seem impossible to get to the same width cross browser. Are there any good guides or tips for accomplishing this? Perhaps there are some default CSS attributes I should be setting.
回答1:
I tested this out in Internet Explorer 7, Firefox 3 and Safari/Google Chrome. I definitely see the problem with <select> and <input type="file">. My findings showed that if you styled all the inputs at the same width, the <select> would be about 5 pixels shorter in all browsers.
Using the Eric Meyer CSS reset script does not help this issue, however if you simply make your <select> inputs 5 pixels wider you'll get very good (albeit not perfect) alignment in the major browsers. The only one that differs is Safari/Google Chrome, and it appears to be 1 or 2 pixels wider than all the other browsers.
As far as the <input type="file"> is concerned, you don't have much flexibility with styling there. If JavaScript is an option for you, you can implement the method shown on quirksmode to achieve greater control over the styling of the file upload control.
See my full working example below in XHTML 1.0 Strict for a typical form with consistent input widths. Note that this does not use the 100% width trick pointed out by others here because it has the same problem with inconsistent widths. Additionally there are no tables used to render the form as tables should only be used for tabular data and not layout.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Example Form</title>
<style type="text/css">
label,
input,
select,
textarea {
display: block;
width: 200px;
float: left;
margin-bottom: 1em;
}
select {
width: 205px;
}
label {
text-align: right;
width: 100px;
padding-right: 2em;
}
.clear {
clear: both;
}
</style>
</head>
<body>
<form action="#">
<fieldset>
<legend>User Profile</legend>
<label for="fname">First Name</label>
<input id="fname" name="fname" type="text" />
<br class="clear" />
<label for="lname">Last Name</label>
<input id="lname" name="lname" type="text" />
<br class="clear" />
<label for="fav_lang">Favorite Language</label>
<select id="fav_lang" name="fav_lang">
<option value="c#">C#</option>
<option value="java">Java</option>
<option value="ruby">Ruby</option>
<option value="python">Python</option>
<option value="perl">Perl</option>
</select>
<br class="clear" />
<label for="bio">Biography</label>
<textarea id="bio" name="bio" cols="14" rows="4"></textarea>
<br class="clear" />
</fieldset>
</form>
</body>
</html>回答2:
I usually put them inside a div or table cell (horrors! I know) of the width I want, then set the select and input style:width to 100% so they fill the div / cell they are in.
回答3:
I found that if you set select and input element border and padding to 0, they are same width. (Tested on Chrome 14, Firefox 7.0.1, Opera 11.51, IE 9)
Putting 1px border/padding on select and input elements makes input element 2 pixels wider. For example:
<form class="style">
<input name="someInput" />
<select name="options">
<option value="1">Value 1</option>
<option value="2">Value 2</option>
</select>
</form>
.style select {
width: 100px;
padding: 1px;
border: 1px solid black;
}
.style input {
width: 96px; /* -2 px for 1px padding(1px from each side) and -2px for border
(select element seems to put border inside, not outside?) */
padding: 1px;
border: 1px solid black;
}
回答4:
Other than width, I'd be setting border and margin too, these may or may not influence your controls. Something like this may help:
input, select {
width: 100px;
margin: 0px;
border: 1px solid;
}
Ron has a good idea too.
回答5:
Do you start your CSS files with some base settings? It may be useful to turn padding and margin off on all elements. I haven't tested to see if this could be affecting select / input elements.
Here's an example CSS Reset from Eric Meyer:
http://meyerweb.com/eric/thoughts/2007/05/01/reset-reloaded/
回答6:
File inputs can be fundamentally different across browsers and definitely don't allow much in the way of customization, which can be annoying, but I also understand why that is from a security perspective. For example, try changing the text of the "browse" button that appears on most browsers, or compare the file input on Safari to other browsers...
回答7:
I don't think Ron's idea works...
test case:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title></title>
<link href="styles/reset.css" rel="stylesheet" type="text/css"/>
<style type="text/css">
input, select{
width: 100%;
}
</style>
</head>
<body>
<div style="width: 200px;">
<input type="text">
<select>
<option>asdasd</option>
<option>asdasd</option>
</select>
</div>
</body>
</html>
This results in the input being some px wider than the select (this is probably OS-dependent). I'm not sure if this could be achieved, even with the +5px trick as the styling of the select seems to be OS (at least windows theme) dependent.
回答8:
If you desperately need { width: 100%; } and not specified with widths in pixels, then jQuery is your friend:
$(function () {
var allSelects = $('input[type="text"], textarea');
allSelects.css('width', (allSelects.width()-6)+'px');
}
-6 pixels works best for me (FF9), edit as you see fit.
回答9:
This is because with an <input>, the border and padding is added on to the width (like with most other elements). With a <select>, the border and padding is included in the width, just like in the old IE quirks mode.
You can get round this by increasing the width to take account of this:
input { width: 200px; padding: 10px; border-width:5px; }
select { width: 230px; padding: 10px; border-width:5px; }
Or (if you can rely on browser support) you can use the new CSS3 box-sizing property to make them behave consistently, and draw padding and border outside of the element width:
input, select {
width: 200px;
padding: 10px;
border-width:5px;
-webkit-box-sizing: content-box; /* Safari/Chrome, other WebKit */
-moz-box-sizing: content-box; /* Firefox, other Gecko */
box-sizing: content-box; /* Opera/IE 8+ */
}
Alternatively, you can set box-sizing to border-box to make the inputs behave like the selects, with padding drawn inside the width of the box.
Tested in Chrome, IE8, FF
来源：https://stackoverflow.com/questions/180647/how-to-line-up-html-input-elements