RangeValidator Can't Count?

Question

I am trying to validate length of a string in a TextBox. Controls on page defined as follows:

<asp:TextBox runat="server" ID="TB" />
<asp:RangeValidator runat="server" ID="RV" 
MinimumValue="3" MaximumValue="20" 
ControlToValidate="TB" Type="String" />

But when page runs there is run time error occurred

The MaximumValue 20 cannot be less than the MinimumValue 3

`RangeValidator` is used to validate a range of numbers, not the range in the length of strings. — Oded, Jun 21 '11 at 12:48

score 13 · Accepted Answer · answered Jun 21 '11 at 12:47

13

You mention Type incorrect, it should be Type="Integer" instead Type="String"

answered Jun 21 '11 at 12:47

Muhammad Akhtar

51,913
37
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Would changing the type to integer, help the user in validating the length of string? – Hasan Fahim Jun 21 '11 at 13:19
Thanks Muhammad. I have had a similar problem. I have defined rangevalidator for integer values, but I haven't specified Type attribute. I noticed several times that if textbox in gridviewrow had have rangevalidator from 1 to 10, only 1 and 10 values were accepted by validator. I think that validator use string type if it is not specified. – Rudolf Dvoracek Sep 14 '12 at 14:32
2

This answer does not match the question. Specifying `Type="Integer"` will not cause the `RangeValidator` to validate the length of the `Text` attribute. It only causes the string to be parsed as an integer. – jsumrall Oct 09 '13 at 19:30

Hasan Fahim · Answer 2 · 2011-06-21T13:01:42.647

Just use TextBox's MaxLength propery. That is used to Get/Set maximum number of characters allowed in the text box.

For minimum length you'll need to use a CustomValidator. In that call a js function which checks the length of the string.

Try this:

<asp:TextBox runat="server" ID="TB" />    
<asp:CustomValidator runat="server" ID="CustomValidator1" ControlToValidate="TB"
    Text="The text length should be between 3 and 20" 
    ClientValidationFunction="clientValidate" Display="Dynamic">
</asp:CustomValidator>


<script type="text/javascript">
function clientValidate(sender, args) {
    if (args.Value.length < 3 ||args.Value.length > 20) {
        args.IsValid = false;
    }
}

score 3 · Answer 3 · answered Jun 21 '11 at 12:51

3

You can not validate the length of a TextBox using a RangeValidator !! RangeValidator is used to validate the value of a field, not the length of this value.

To do that you can use other ways as CustomValidator.

answered Jun 21 '11 at 12:51

Akram Shahda

14,655
4
45
65

score 0 · Answer 4 · answered Jan 31 '22 at 21:54

The syntax that worked for me correctly

 <asp:RegularExpressionValidator ID="RegularExpressionValidator34" runat="server" ControlToValidate="fname" 
            Display="Dynamic" ErrorMessage="email is required" ForeColor="Red" SetFocusOnError="True" 
            ValidationExpression="(\s|.){5,10}"> 
                  Length must between (5-10) characters</asp:RegularExpressionValidator>

RangeValidator Can't Count?

4 Answers4