Javascript 要取消输入文本框的默认值吗
如果我问错了这个问题,请不要投反对票。我有一个这样的文本框:Javascript 要取消输入文本框的默认值吗,javascript,html,textbox,Javascript,Html,Textbox,如果我问错了这个问题,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" /> 它当前持有一个默认值。我希望在单击文本框时清除默认值并替换为光标。HTML: <input type="text" value="user name" id="userName" /> 编辑:这里有一个将以下内容作为属性添加到输
<input class="login-inpt" runat="server" name="loginName" type="text" value="User Name" />
它当前持有一个默认值。我希望在单击文本框时清除默认值并替换为光标。HTML:
<input type="text" value="user name" id="userName" />
编辑:这里有一个将以下内容作为属性添加到输入标记中:
onfocus="if(this.value=='A new value') this.value='';"
发件人:您可以试试这个
<input type="text" value="user name" onfocus="if(this.value=='user name') this.value='';">
对于更新的浏览器IE>9:
我得到了答案,谢谢。
输入类型=文本id=用户名onfocus=inputFocusthis onblur=inputBlurthis
函数inputFocusi{if i.value==i.defaultValue{i.value=;i.style.color=000;}}}函数inputBluri{if i.value=={i.value=i.defaultValue;i.style.color=888;}}您已经得到了很好的答案,但如果您是新手,您可能会对它在没有库的情况下如何工作感兴趣 以下是HTML:
查看此处查看此解决方案:此问题与您的问题非常相似:为什么在ASP.NET MVC 3视图中有runat=server属性?您似乎混淆了经典的ASP.NET WebForms和ASP.NET MVC。您正在使用这两种技术中的哪一种?您的问题与asp.net MVC无关。这是一个html/javascript问题。我编辑了您的问题。我正在使用Asp.net MVC3。我通过使用OnFocus和OnBlur事件获得了解决方案。感谢大家。这确实是最好的方法,可以跨浏览器工作,因为这在旧版本的Internet Explorer中不起作用。如果您只针对最新版本的Internet Explorer,那么它是一个不错的选择。函数inputFocusi{if i.value==i.defaultValue{i.value=;i.style.color=000;}}}函数inputBluri{if i.value==i.defaultValue;i.style.color=888;}
<input type="text" value="user name" onfocus="if(this.value=='user name') this.value='';">
<input type="text" id="userName" placeholder="User Name" />
<!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>
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();
<input id="textBox" class="textBox phrase" type="text" value="Enter Your Text..">
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;
});
$('.login-inpt').focus(function() {
$(this).val('');
});
$('.login-inpt').focusout(function() {
$(this).val('User Name');
});