<script language="javascript" type="text/javascript">
function passHint() {
var txt = document.getElementById('txtPass').value;
if (txt.length < 6)
{ document.getElementById('labweak').Visible = true; }
else
{ document.getElementById('labstrong').Visible = true; }
}
</script>我想获得txtPass TextBox控件的内容,验证他的长度>6 <6的功能,以上代码有误,求解
function passHint() {
var txt = document.getElementById('txtPass').value;
if (txt.length < 6)
{ document.getElementById('labweak').Visible = true; }
else
{ document.getElementById('labstrong').Visible = true; }
}
</script>我想获得txtPass TextBox控件的内容,验证他的长度>6 <6的功能,以上代码有误,求解
var s ="sssss";
if(s.length<=3)
{
alert("<=3");
}
if(s.length>3)
{
alert(">3");
}
</script>
那它们根本就没有Render到前台去。
你先把它们Visible=False的代码去掉
然后在Page_Load里改成:
this.labweak.Style["display"]="none";
this.labstrong.Style["display"]="none";最后把你的js代码改为:
<script language="javascript" type="text/javascript">
function passHint() {
var txt = document.getElementById('txtPass').value;
if (txt.length < 6)
{ document.getElementById('labweak').style.display = "block"; }
else
{ document.getElementById('labstrong').style.display = "block"; }
}
</script>
调试到这一句的时候,弹出错误缺少对象
再仔细检查下
如何是服务器控件,那就要这样document.getElementById("<%=txtPass.ClientID%>").value;
document.getElementById("labweak").style.display="none";这样来控制
function passHint() {
var txt = document.getElementById('txtPass').value;
if (txt.length < 6)
{ document.getElementById('labweak').style.display = "none"; }
else
{ document.getElementById('labstrong').style.display = "block"; }
}
</script>
function passHint() {
var txt = document.getElementById('txtPass').value;
if(document.getElementById('txtPass') == null){
alert("没找到 txtPass");
return;
}
if (txt.length < 6)
{ document.getElementById('labweak').style.display = "block"; }
else
{ document.getElementById('labstrong').style.display = "block"; }
}
</script>