regular+required validation - asp.net

Question

<asp:TextBox ID="Textboxtotalamount" OnTextChanged="AmountChanged"
Width="90px" AutoPostBack="true" runat="server">
</asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator" runat="server"
ControlToValidate="Textboxtotalamount"
SetFocusOnError="True" ValidationGroup="val">*</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"
ControlToValidate="Textboxtotalamount"
ValidationExpression="^[-+]?[1-9]\d{0,13}(\.\d{1,3})?%?$"
SetFocusOnError="True">F</asp:RegularExpressionValidator>
in this above code can validate correctly.......but in text box i call "OnTextChanged"
event ....suppose if i type(characters)in textbox errormesge shown at the same time ontextchanged event also called hen error occured ....i ve to stop OnTextChanged event when regularexpression raised......
pls help

Answer 1

I updated your code. see if this helps you.
<asp:TextBox ID="Textboxtotalamount" OnTextChanged="AmountChanged" ValidationGroup="val"
Width="90px" AutoPostBack="true" runat="server" CausesValidation="true">
</asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator" runat="server" ValidationGroup="val"
ControlToValidate="Textboxtotalamount"
SetFocusOnError="True" >*</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"
ControlToValidate="Textboxtotalamount" ValidationGroup="val"
ValidationExpression="^[-+]?[1-9]\d{0,13}(\.\d{1,3})?%?$"
SetFocusOnError="True">F</asp:RegularExpressionValidator>

Answer 2

I'm not sure I understood your question correctly: You want to execute the `AmountChanged´ code only if the validator did not report any errors, right? In that case, you should call
if (!this.IsValid)
return;
at the start of AmountChanged. (You might need to call this.Validate(); first, if OnTextChanged does not initiate validation by itself.)
Details can be found here: http://msdn.microsoft.com/en-us/library/dh9ad08f(VS.100).aspx
Clarification: At the moment, your code looks like this:
void AmountChanged(...) {
...
}
You need to change it to this:
void AmountChanged(...) {
if (!this.IsValid)
return;
...
}
so that the code is not executed when some validator detects an error. In addition, you must add CausesValidation="true" to your TextBox as Saar's example shows.