asp:TextBox and MaxLength

Question

I wrote this:

<asp:TextBox ID="txtSMSMessaggio" CssClass="inputForm" MaxLength="240" TextMode="MultiLine" runat="server"></asp:TextBox>

but on client side I can't see the attribute maxlength (which I need). Why? And how can I fix it?

@RGraham: no that's another kind of question. I want that attributes appair on client. — markzzz, Sep 10 '13 at 14:55

CodingIntrigue · Accepted Answer · 2013-09-10T15:04:50.623

1

Can you just use a <textarea> tag and add runat="server"?

<textarea id="txtSMSMessaggio" class="inputForm" maxlength="240" runat="server"></textarea>

edited Sep 10 '13 at 15:04

answered Sep 10 '13 at 14:58

CodingIntrigue

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No, because I can't use that textarea as controls in the .cs. Such as txtSMSMessaggio.Text – markzzz Sep 10 '13 at 15:00
1

Declaring a `` with a `runat=server` attribute will give you access to a [HtmlTextArea](http://msdn.microsoft.com/en-us/library/system.web.ui.htmlcontrols.htmltextarea.aspx) in the code-behind. Not a 1-to-1 map, but still gives you access to the control. – CodingIntrigue Sep 10 '13 at 15:02
You need to use [txtSMSMessaggio.Value](http://msdn.microsoft.com/en-us/library/system.web.ui.htmlcontrols.htmltextarea.value.aspx) instead – CodingIntrigue Sep 10 '13 at 15:17

score 1 · Answer 2 · answered Apr 16 '14 at 20:29

you might not be interested in counting the characters in the TextBox, but its helpful to let the end user know there is a limit before it is reached. you can do something like

<script language="javascript" type="text/javascript">
var Maxlength = 240;
function taLimit() {
 var srcObject = event.srcElement;
 if (srcObject.value.length == Maxlength * 1) return false;
}

function taCount(tagName) {
 var srcObject = event.srcElement;
 if (srcObject.value.length > Maxlength * 1) srcObject.value = srcObject.value.substring(0, Maxlength * 1);
 if (tagName) visCnt.innerText = Maxlength - srcObject.value.length;
}
</script>

<asp:TextBox ID="txtSMSMessaggio" CssClass="inputForm" TextMode ="MultiLine" runat="server" 
onkeypress="return taLimit()" onkeyup="return taCount(Counter)" onfocus="return
taCount(Counter)" ></asp:TextBox><br />
(<span id="Counter">240</span> characters left)<br />

score 0 · Answer 3 · answered Sep 10 '13 at 14:57

You can try a Regular Expression to restrict the user to 240 characters:-

<asp:RegularExpressionValidator runat="server" ID="txtSMSMessaggio"
ControlToValidate="txtInput"
ValidationExpression="^[\s\S]{0,240}$"
ErrorMessage="Some error message"
Display="Dynamic">*</asp:RegularExpressionValidator>

asp:TextBox and MaxLength

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