I'm working on an application with two input fields that's validated in different ways with RequiredFieldValidator, RangeValidator and so on. I need one more validation and that is to check that the number the user writes in input1 isn't bigger than in input2, and here's the question.
Is it possible to use validation controls to compare 2 input fields, or do I need to write code for it? I'm using a ValidationSummary control and of course I want to show all the errors with this. If it isn't possible to use validation controls to compare 2 input fields and I need to write code for this, is it possible to show the error message with the ValidationSummary anyway, and in that case how?
Thanks in advance!
You can use the CompareValidator.
See here for an example.
Use a custom validator control and use the ServerValidate event to return true/false depending on if the check is correct.
The validation summary will pick up that the Page is not valid and display your message.
C#
protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs args)
{
if (TextBox1.Text.Length > TextBox2.Text.Length)
args.IsValid = false;
else
args.IsValid = true;
}
.aspx
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:ValidationSummary ID="ValidationSummary1" runat="server" />
<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="Invalid Length" Display="None" onservervalidate="CustomValidator1_ServerValidate"></asp:CustomValidator>
<br />
<asp:Button ID="Button1" runat="server" Text="Button" />
Have you tried using the CompareValidator?
This allows you to compare 2 input fields and is a standard control as per the Requiredfield and Range validators.
<asp:CompareValidator ControlToCompare="text1" ControlToValidate="text2" ErrorMessage="error" runat="server" Operator="LessThan" Type="Integer" />
bool isLonger(string s1, string s2)
{
return s1.Length > s2.Length ? true : false;
}
returns true if the length if s1 is greater than the length of s2
Related
I have a Textbox on my webform, for instance 2012 entered in single text box the following text box must enter 2014 or else should give error.Iam trying to validate it by using compare validation but am unable to meet the exact condition what i want.Can i know how can it be done?thnks in advance
I cant fine wha'ts the hard part here...
int number=Convert.ToInt32( textBox1.Text);
if(number==2014)
Response.Write("good");
else
Response.Write("Bad number");
More easy then that?
If your validator should ensure that the text in two TextBoxes is equal use a CompareValidator with appropriate ControlToValidate and ControlToCompare:
<asp:TextBox id="Txt1" runat="server">
</asp:TextBox>
<asp:TextBox id="Txt2" runat="server">
</asp:TextBox>
<asp:CompareValidator ID="CompareValidator1" runat="server"
ControlToValidate="Txt2"
ControlToCompare="Txt1"
ErrorMessage="Text in second textbox must be equal to text in first textbox!">
</asp:CompareValidator>
If you also want to ensure that only integers can be inserted, use DataTypeCheck and Integer:
<asp:CompareValidator ID="CompareValidator2" runat="server"
ControlToValidate="Txt2"
Type="Integer" Operator="DataTypeCheck"
ErrorMessage="Text in second textbox must be an integer!">
</asp:CompareValidator>
I am using custom validator tool in asp.net to check whether a text box is blank or not(I did not use requiredfieldvalidator because the text box in question is going to be enabled occasionally).The problem is that the custom validator event in code behind is not firing at all.This is the source code:
<asp:TextBox ID="txtS_rentSDate" runat="server" Font-Names="Bookman Old Style"
Font-Size="Medium" Width="326px"
ontextchanged="txtS_rentSDate_TextChanged"
CausesValidation="True"></asp:TextBox>
<asp:CustomValidator ID="cvRentSDate" runat="server"
ControlToValidate="txtS_rentSDate"
ErrorMessage="Please enter the rent start date"
onservervalidate="cvRentSDate_ServerValidate" ValidateEmptyText="True"
Width="180px"></asp:CustomValidator>
Code behind:
protected void cvRentSDate_ServerValidate(object source, ServerValidateEventArgs args)
{
args.IsValid = (args.Value.Length > 0);
}
Kindly let me know where I am going wrong and what is the proper way to do it?
<asp:CustomValidator ID="cvRentSDate" runat="server"
ControlToValidate="txtS_rentSDate"
ErrorMessage="Please enter the rent start date"
OnServerValidate="cvRentSDate_ServerValidate" ValidateEmptyText="True"
Width="180px"></asp:CustomValidator>
Try with my above lines. May be you need to use OnServerValidate instead of onservervalidate.
I have an asp:textbox with both required and range validators attached to it, where the code looks like this:
ASP:
<asp:TextBox ID="textBox1" runat="server" CausesValidation="true"></asp:TextBox>
<asp:RangeValidator ID="rangeValidator1" runat="server" ControlToValidate="textBox1" MaximumValue="1" MinimumValue="0"
ValidationGroup="valid" ForeColor="Red" ErrorMessage="Out of Range" />
<asp:RequiredFieldValidator ID="requiredValidator1" runat="server" ControlToValidate="textBox1"
ValidationGroup="valid" ForeColor="Red" ErrorMessage="Cannot be blank" />
And when the page is dynamically loaded (after a quick callback), I have code that is supposed to change the MaximumValue of the RangeValidator to more specific value. Here is the code for that:
rangeValidator1.MaximumValue = GetMaxValue(params).ToString();
Now, I have set a breakpoint, and rangeValidator1.MaximumValue is being set correctly, however, when the page loads, and I look at the compiled client side javascript, it appears that the maximum value is still only 1.
What confuses me more is that any integer typed in will pass, as long as the first digit is a '1'. So if the maxValue is supposed to be something like "1234567", "1" will match, as will "12345678910". But "2" will not. Nor will "3000" or "46000".
Has anyone else had a similar issue with RangeValidators on Textboxes?
The RangeValidator handles validation for multiple types. You should make sure to set the Type to Integer. or what ever is appropriate.
Hi I am working on a custom form field validator, it seems like the custom validator is working by not allowing it to continue to the next page, but it doesn't update the Validation Summary nor does it display the asterisk and the labels that i've made visable. I also have other validators like RequiredFieldValidator on the same field. My ValidationGroup is set, as is the Text and IsValid. I even wrote and set a dummy client side validation method in javascript as some workarounds suggests.
here is the validation summary code in asp.net
<asp:ValidationSummary ID="ValidatorSummary" runat="server" ValidationGroup="Step2" />
here is the custom validator and the required field one
<asp:CustomValidator ID="AddressVerification" runat="server" ErrorMessage="Please enter a valid address." Display="Dynamic" ValidationGroup="Step2" OnServerValidate="AddressVerification_ServerValidate" ClientValidationFunction="CustomValidatorDummy" Text="*" Enabled="true" EnableClientScript="true"></asp:CustomValidator>
<asp:RequiredFieldValidator ID="RFValidatorHomeAddress" runat="server" ErrorMessage="Please enter home address." Text="*" Display="Dynamic" ValidationGroup="Step2" ControlToValidate="txtHomeAddress"></asp:RequiredFieldValidator>
here is the custom validation method in the code behind
protected void AddressVerification_ServerValidate(object sender, ServerValidateEventArgs e)
{
//lets just say it doesn't validate and sets the IsValid to false
lblUspsValidatorResHomeCity.Visible = true;
lblUspsValidatorResHomeState.Visible = true;
lblUspsValidatorResHomeZip.Visible = true;
e.IsValid = false;
}
please advise, thanks.
EDIT:
Answered - as bitxwise mentioned. the validation summary should be placed inside an update panel as well. Thanks!
Like so:
<asp:UpdatePanel ID="UpdatePanelValidationSummaryHome" ChildrenAsTriggers="false" UpdateMode="Conditional"
runat="server">
<ContentTemplate>
<asp:ValidationSummary ID="AddressHomeValidationSummary" runat="server" ValidationGroup="AddressHomeValidationGroup"
CssClass="errors" />
</ContentTemplate>
and then calling the update:
UpdatePanelValidationSummaryHome.Update();
You seem to be missing ControlToValidate in your declaration of CustomValidator.
EDIT
If your CustomValidator aggregates multiple controls, then try this:
ASPX
<asp:TextBox ID="txtMyTextBox" runat="server" />
<asp:CustomValidator ID="AddressVerification" runat="server"
Display="Dynamic"
ErrorMessage="Please enter a valid address."
OnServerValidate="AddressVerification_ServerValidate"
Text="*"
ValidationGroup="Step2" />
<asp:RequiredFieldValidator ID="rfvAddress" runat="server"
ControlToValidate="txtMyTextBox"
Display="Dynamic"
ErrorMessage="Please enter an address"
Text="*"
ValidationGroup="Step2" />
...
<asp:ValidationSummary ID="ValidatorSummary" runat="server"
ValidationGroup="Step2" />
...
<asp:Button ID="btnCheckAddresses" runat="server"
CausesValidation="true"
Text="Check Addresses"
ValidationGroup="Step2" />
CS
protected void AddressVerification_ServerValidate(object source, ServerValidateEventArgs args) {
args.IsValid = !string.IsNullOrEmpty(txtMyTextBox.Text) && !txtMyTextBox.Text.Contains(' ');
}
Note that the validation group of the control invoking the post back has CausesValidation="true" and has the same ValidationGroup as the validators.
EDIT 2
If your postback control was in the UpdatePanel but the ValidationSummary was not, then the partial postback would not have refreshed the ValidationSummary. Once you removed the postback control from the UpdatePanel, I imagine it would then generate a full postback, which would refresh your ValidationSummary.
I don't know what else is in your UpdatePanel, but many people report having issues with their validators being in UpdatePanel's.
Check out MSDN,
When you use the ValidationSummary
control inside an UpdatePanel control,
make sure that the validator control
and the control it is associated with
are in the same panel. For more
information about using the
UpdatePanel control for partial-page
updates, see Partial-Page Rendering
Overview.
as well as this MSDN blog.
Make sure every control (textbox, checkbox, etc) that is being validated, every RequiredValidator, CustomValidator and ValidationSummary has the same ValidationGroup value.
ie.
<asp:CustomValidator ID="CustomValidator6" runat="server" ErrorMessage="The field is required"
ValidationGroup="myValGroup">*</asp:CustomValidator>
Of course this will only work if all the controls are inside the same panel or parent control.
In my case the validation summary was not showing because the submit button was in a separate update panel.
<Triggers>
<asp:PostBackTrigger ControlID="ButtonSubmit" />
</Triggers>
Once I added the above code the summary appeared.
If a user enters a non-numeric value into a TextBox and presses a Button, I want to show an error message on a Label.
How can I achieve this?
If you're working with ASP.NET webforms, perhaps you have some markup like this:
<asp:TextBox runat="server" ID="TextBox1" Text="Default Text!" />
<asp:Button ID="Button1" runat="server" Text="Click Me" OnClick="ChangeIt" />
<br />
<br />
<asp:Label ID="Label1" runat="server" Text="default!" />
Then your code-behind will need a method to handle the button's click event. This will cause a post-back.
protected void ChangeIt(Object sender,EventArgs e)
{
// ensure that the value in the textbox is numbers only.
// there are always questions here whether you care about
// decimals, negative numbers, etc. Implement it as you see fit.
string userEnteredText = TextBox1.Text.Trim();
long resultantNumber;
if (!long.TryParse(userEnteredText, out resultantNumber))
{
Label1.Text = string.Format( "It looks like this isn't a number: '{0}'",
userEnteredText);
}
}
Are you saying you want to allow numbers only?
<asp:TextBox runat="server" ID="TextBox1" />
<asp:RegularExpressionValidator runat="server" ID="RegularExpressionValidator1" ControlToValidate="TextBox1" ErrorMessage="Digits only, please" ValidationExpression="^\d+$" />
If this will allow numbers only, but will also allow you to skip the box entirely. If you want to make it required, add this:
<asp:RequiredFieldValidator runat="server" ID="RequiredFieldValidator1" ControlToValidate="TextBox1" ErrorMessage="Required" />
Update: If you would like to accept decimal values like "3.5" in addition to just "3", modify the ValidationExpression in the RegularExpressionValidator I supplied above to read "^\d+(\.\d+)?$"
Assuming you want to check whether the input is a number or a string (and display an error if the input is a string), you could do something like this using the int.TryParse function:
protected void Button1_Click(object sender, EventArgs e)
{
int readValue;
if (!int.TryParse(TextBox1.Text, out readValue))
Label1.Text = "Error";
}