本文實例講述了JavaScript監聽文本框回車事件並過濾文本框空格的方法。分享給大家供大家參考。具體如下：
<script type="text/javascript" language="javascript">
var username = null;
var password = null;
//獲取文本框
onload = function()
{
username = document.getElementById("txtUserName");
password = document.getElementById("txtPassWord");
}
//清空文本框
function clearTxt()
{
username.value = "";
password.value = "";
username.focus();
// document.getElementById('txtUserName').value="";
// document.getElementById('txtPassWord').value="";
// document.getElementById('txtUserName').focus();
}
//確定
function chkTxt()
{
//刪除前後空格
username.value = username.value.replace(/(^\s*)|(\s*$)/g,"");
password.value = password.value.replace(/(^\s*)|(\s*$)/g,"");
//判空
if(username.value.length == 0)
{
alert("請輸入用戶名!");
username.focus();
}
else if(password.value.length == 0)
{
alert("請輸入密碼!");
password.focus();
}
else
document.getElementById("btnLogin").click();
}
//回車監聽
function onkey()
{
if (window.event.keyCode==13)
{
// document.all["btnLogin"].focus();
// if(document.activeElement.id = "aReset")
//判斷當前焦點所在的控件的id是aReset
// {
// document.getElementById("aReset").focus();
// }
document.getElementById("aLogin").focus();
return false;
}
}
</script>
css代碼：
<style type="text/css">
#btnLogin
{
width: 0px;
height: 0px;
border-style: none;
background-color: White;
}
</style>
html代碼：
<body onkeydown="onkey()">//把回車監聽加入body
<form id="login_form" name="login_form" runat="server">
<div>
<label>用戶：</label><input id="txtUserName"
runat="server" name="u_name" class="input bold" type="text"/>
<label>密碼：</label><input id="txtPassWord"
runat="server" name="u_pass" class="input" type="password"/>
<a href="javascript:chkTxt()" id="aLogin">確定</a>
<%--<a href="javascript:document.forms['login_form'].reset()">
重置</a>--%>
<a href="javascript:clearTxt()" id="aReset">重置</a>
<asp:Button ID="btnLogin" runat="server"
Text="" OnClick="btnLogin_Click" />
</div>
</form>
</body>
希望本文所述對大家的javascript程序設計有所幫助。