javascript 想要消除输入文本框的默认值
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Want to disapper input textbox default value
提问by AJay Garg
Please do not give a negative vote if I am wrong with asking this question. I have a TextBox like this:
如果我问这个问题有误，请不要投反对票。我有一个这样的文本框：
<input class="login-inpt" runat="server" name="loginName" type="text" value="User Name" />
It currently holds a default value. I want the default value to be cleared and replaced with a cursor when I click on the TextBox.
它目前拥有一个默认值。我希望在单击 TextBox 时清除默认值并替换为光标。
回答by kayz1
For newer browsers (IE>9):
对于较新的浏览器（IE>9）：
<input type="text" id="userName" placeholder="User Name" />
For older:
对于老年人：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Placeholder support</title>
</head>
<body>
<input type="text" id="userName" placeholder="User Name" />
<script src="../js/vendor/jquery-1.10.2.min.js"></script>
<script src="../js/vendor/jquery-migrate-1.2.1.js"></script>
<script src="../js/vendor/modernizr-latest.js"></script>
<script src="../js/placeholder.js"></script>
</body>
</html>
placeholder.js (jQuery, Modernizr)
placeholder.js (jQuery, Modernizr)
var Placeholder = (function ($, document) {
/* Static Content */
var _$document = $(document);
/* Events */
var _initPlaceholders = function () {
_$document.find('input:text').each(function () {
var $this = $(this);
$this.css({ color: '#888' }).val($this.attr('placeholder'));
});
};
var _placeholderEvent = function () {
var $input = $(this), placeholderValue = $input.attr('placeholder');
if ($input.val() === placeholderValue) {
$input.css({ color: '#000' }).val('');
return;
}
if ($input.val() === '') {
$input.css({ color: '#888' }).val(placeholderValue);
}
};
var _bindEvents = function () {
if (!Modernizr.input.placeholder) {
_initPlaceholders();
_$document.on('focus blur', 'input:text', _placeholderEvent);
}
};
var init = function () {
_bindEvents();
};
return {
init: init
};
})(jQuery, document);
Placeholder.init();
回答by zigdawgydawg
回答by Jatin patil
You can try this
你可以试试这个
<input type="text" value="user name" onfocus="if(this.value=='user name') this.value='';">
回答by nkirkes
add the following as an attribute to your input tag:
将以下作为属性添加到您的输入标签：
onfocus="if(this.value=='A new value') this.value='';"
回答by AJay Garg
I got the solution Thanks. input type="text" id="userName" onfocus="inputFocus(this)" onblur="inputBlur(this)"
我得到了解决方案 谢谢。input type="text" id="userName" onfocus="inputFocus(this)" onblur="inputBlur(this)"
function inputFocus(i) { if (i.value == i.defaultValue) { i.value = ""; i.style.color = "#000"; } } function inputBlur(i) { if (i.value == "") { i.value = i.defaultValue; i.style.color = "#888"; } }回答by orustammanapov
You already got good answers but if you are newbie it might interest you how it could work without libraries.
您已经得到了很好的答案，但如果您是新手，您可能会对它如何在没有库的情况下工作感兴趣。
Here is HTML:
这是 HTML：
<input id="textBox" class="textBox phrase" type="text" value="Enter Your Text..">
you don't need to set class and id you could pick one of them
你不需要设置 class 和 id 你可以选择其中之一
Here is JavaScript:
这是 JavaScript：
var textBox = document.getElementById('textBox'), //probably the fastest method
/**************************additionally possible****************************
var textBox = document.getElementsByTagName('input')[0], //returns HTMLInputElement list (since we've got only one we chose the first one)
or
var textBox = document.querySelectorAll('textBox'), //works almost the same way as jquery does except you don't get all jquerys functionality
or
var textBox = document.getElementsByClassName('textBox')[0], //i guess its a least supported method from the list
***************************************************************************/
//text you want to choose for you input
phrase = "Enter Your Text..";
function addEvent(el, ev, fn) {
//checking method support
//almost every browser except for ie
if(window.addEventListener) {
el.addEventListener(ev, fn, false);
}
//ie
else if(window.attachEvent) {
el.attachEvent('on' + ev, fn);
el.dettachEvent('on' + ev, fn);
}
}
addEvent(textBox, 'focus', function (){
//cross browser event object
var e = e || window.event,
target = e.target;
//if the text in your text box is your phrase then clean it else leave it untouched
target.value = target.value === phrase ? "" : target.value;
});
addEvent(textBox, 'blur', function (){
//cross browser event object
var e = e || window.event,
target = e.target;
//if your text box is not empty then leave it else put your phrase in
target.value = target.value ? target.value : phrase;
});
回答by mint
$('.login-inpt').focus(function() {
$(this).val('');
});
$('.login-inpt').focusout(function() {
$(this).val('User Name');
});
check out here http://jsfiddle.net/TDUKN/
