I have developed a small form with 3 input type = text and one input type = submit button. The end user fills the form and submit it, but no data inserted into backend table. (probably empty form is submitted). I get to know that Javascript is disabled on user's browser. Now i want to do server side validation. How i validate my form on server side? I need a piece of code to validate form on server side (code behinde) ? I need code in asp.net
You really should not ask for straight forward code on this forum. But either way here is a great resource for asp.net form validation: MSDN - Validating ASP.NET Server Controls
Essentially, assuming you are using C#, you might do something like this:
<%# Page Language="C#" %>
<script runat="server">
void Button1_Click(Object sender, EventArgs e) {
Label1.Text = "Page is valid!";
}
</script>
<html>
<head>
</head>
<body>
<form runat="server">
<p>
<asp:TextBox id="TextBox1"
runat="server"></asp:TextBox>
<asp:RequiredFieldValidator
id="RequiredFieldValidator1" runat="server"
ErrorMessage="Required!"
ControlToValidate="TextBox1">
</asp:RequiredFieldValidator>
</p>
<p>
<asp:Button id="Button1" onclick="Button1_Click"
runat="server" Text="Button"></asp:Button>
</p>
<p>
<asp:Label id="Label1" runat="server"></asp:Label>
</p>
</form>
</body>
</html>
My recommendation is to try and Google some and look for tutorials - there are pretty informative ones out there available with easy step by step directions.
Happy coding!
Related
I am new to .NET and I am trying out basic functionalities. I got an error when I placed submit button. Please go through the code and let me know if the Submit button syntax I used is wrong.
Code :
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>My First web page</title>
</head>
<body>
<form id="form1" runat="server" >
<div style="position:absolute">
First Name :<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br/>
Last Name :<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<asp:Button OnClick="submit" Text="submit" runat="server" />
</div>
</form>
</body>
</html>
Error is :
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.
Compiler Error Message: CS1061: 'ASP.webform1_aspx' does not contain a definition for 'submit' and no extension method 'submit' accepting a first argument of type 'ASP.webform1_aspx' could be found (are you missing a using directive or an assembly reference?)
Thank You.
You have to provide the server side OnClick handler to OnClick and probably submit is not defined as handler. This MSDN Button.OnClick documentation tell how OnClick event handler is attached with button. You also need to provide the ID to your button.
Remove the OnClick attribute from button. Open the form in VS designer Double click the button in VS designer it will generate handler for you. You can find mode in How to: Create Event Handlers in ASP.NET Web Forms Pages
After generating event handler you would have something like.
Code behind
void yourButtonId_Click(Object sender, EventArgs e)
{
}
HTML (aspx)
<asp:Button ID="yourButtonId" OnClick="yourButtonId_Click" Text="submit" runat="server" />
<script runat="server">
Sub submit(sender As Object, e As EventArgs)
lbl1.Text="Your name is " & txt1.Text
End Sub
</script>
<!DOCTYPE html>
<html>
<body>
<form runat="server">
Enter your name:
<asp:TextBox id="txt1" runat="server" />
<asp:Button OnClick="submit" Text="Submit" runat="server" />
<p><asp:Label id="lbl1" runat="server" /></p>
</form>
</body>
</html>
im trying to build a form+attachment that needs to be send to email.
Im using a VB background code (attachementemail.aspx.vb)
and my front (b-16.aspx)
I want the page to check that the user entered a email, name, phonenumber and attachment.
what command do I put in the axp.vb
and what on the .aspx
tried just about anything.
The simplest way is to use validators eg RequiredFieldValidator for mandatory fields. You can also implement CustomValidators for custom logic.
See http://msdn.microsoft.com/en-us/e5a8xz39.aspx for the available validators
At it's basic level you could use RequiredFieldValidator and CustomValidation in your form. You can use some regex logic for email, I use this but there are many out there:
Regex(#"\w+([-+.]\w+)#\w+([-.]\w+).\w+([-.]\w+)*")
Personally I use client side javascript before it hits the server and then I re-validate the entries once it hits the server. If your using the postback events then you'll need update panels and a scriptmanager (not sure if you are aware of this already, so apologies if teaching you to suck eggs!).
Here is an example:
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
ErrorMessage="RequiredFieldValidator" ControlToValidate="TextBox1"></asp:RequiredFieldValidator>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
Code behind (sorry this is in c#)
protected void Button1_Click(object sender, EventArgs e)
{
if (RequiredFieldValidator1.IsValid)
{
Label1.Text = "Has content";
}
else
{
Label1.Text = "Not valid";
}
}
Note that the required field validator has it's own methods to display a "hey you haven't entered content here my friend" message, but i have added that to the label instead.
Hello all how to use HTML text field instead of ASP.NET textbox.?
How to write C# code to make use of HTML forms instead of ASP.NET
EDIT:
<form id="form1" runat="server">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<input id="Text1" type="text" runat="server" />
<asp:Button ID="Button5"
runat="server" Text="Button" OnClick="button5_click" />
<div>
<script runat="server">
protected void button5_click(object sender, EventArgs e)
{
Text1.Value = "Hello";
}
</script>
</form>
Instead of using or whatever server control, just type in the standard type tags or whichever HTML control you want.
If you want to be able to access them from your code-behind, then just include a runat="server" value with each HTML tag and make sure you give it an ID.
You need to retrieve the value from the HTTP request's Form collection:
<input type="text" name="MyTextField" />
Code behind:
string value = Request.Form["MyTextField"];
This question doesn't make much sense. You really should clarify and flesh out the question and explain what you are trying to do.
In some ways, an ASP.NET textbox is an HTML text field that C# code can make use of. So what's the problem with an ASP.NET textbox?
You can create an instance of a HtmlInput control in code, or alternatively add a runat="server" attribute to an <input> element in your aspx file, you can then access this from server-side code using it's ID.
As an alternative, you may wish to take a look at http://asp.net/mvc to get better control of your HTML markup.
I have a page with a listview that shows something like posts. On each post there should be a "rate box" which works similar to the "Like" button in facebook. The rate box is a User Control, that has an update panel inside it.
If I put the control with some random values in the page it works great - but when I put it inside the ListView, where it should be located, it won't work. The method is being called, but nothing happens.
I simplified the code a bit to make it easier to understand:
The "rate box" control:
protected void OnRateClick(object sender, ImageClickEventArgs e)
{
Rate++;
RateAmountLiteral.Text = Rate.ToString();
RateButton.Visible = false;
FeedbackLiteral.Visible = true;
rateButtonPanel.Update();
}
ascx:
<div class="rate_div">
<asp:UpdatePanel ID="rateButtonPanel" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<fieldset>
Rate:
<asp:Literal ID="RateAmountLiteral" runat="server"></asp:Literal>
<asp:ImageButton ID="RateButton" runat="server" ImageUrl="icn_rate.png"
OnClick="OnRateClick" />
<asp:Literal ID="FeedbackLiteral" runat="server" Visible="false">Thanks for rating!</asp:Literal>
</fieldset>
</ContentTemplate>
</asp:UpdatePanel>
</div>
aspx (using the control):
<asp:ListView ID="PostsView" runat="server" ItemPlaceholderID="itemPlaceHolder2"
<LayoutTemplate>
<div class="posts_div">
<asp:PlaceHolder ID="itemPlaceHolder2" runat="server" />
</div>
</LayoutTemplate>
<ItemTemplate>
<div class="post_div">
<div class="post_body">
<%# CurrentPost.Body %>
</div>
<UC:RatingBox id="RatingBox" runat="server"
PostID="<%# CurrentPost.ID %>"
Rate="<%# CurrentPost.Rate %>"/>
By: <a href="<%# CurrentPost.Author.LinkToProfile %>">
<%# CurrentPost.Author.DisplayName %>
</a> |
<%# CurrentPost.LiteralTime %>
</div>
</ItemTemplate>
</asp:ListView>
While debugging I noticed the controls in the method "OnRateClick" are empty and don't contain the right values. Please advice.
Also if you have any comments about the way I did things, don't hold yourself.
Thanks
There are a lot things that you may not have set up, I cannot tell from just the code snippet you have given. But make sure you do the following: -
1) Place a ScriptManager "" on the page.
If you are using master page in your application and your web page uses the master page, place script manager in master page. Or alternatively,you can also place script manager on specific web pages anyway.
2) Add a Triggers for the button RateButton in your Update panel.
Why does the following give me a compilation error for line B (Label2, outside UpdatePanel) but not for line A (Label1, inside UpdatePanel)? I would have expected both lines to give an error since both controls are within the same Repeater and should therefore not be directly accessible outside the repeater, since there is no one unique instance.
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Label1.Text = Label1.ClientID; // Line A - compiles fine
Label2.Text = Label2.ClientID; // Line B - "The name 'Label2' does not exist in the current context"
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:Repeater runat="server" ID="Repeater1">
<ItemTemplate>
<asp:UpdatePanel runat="server" ID="UpdatePanel1">
<ContentTemplate>
<asp:Label ID="Label1" runat="server" Text="Label1" />
</ContentTemplate>
</asp:UpdatePanel>
<asp:Label ID="Label2" runat="server" Text="Label2" />
</ItemTemplate>
</asp:Repeater>
</div>
</form>
</body>
</html>
I'm betting if you comment out line B you'll get a run-time error on execution. Label1 is going to be a null reference.
When you create controls in the ASPX page Visual Studio tries to help you out by adding the controls to the code behind in the designer file which extends the class for the page. In this case it's adding one when it shouldn't be.
Short answer is it's a bug. You should submit it but it shouldn't be a blocking issue.
Real question is why are you creating multiple update panels in a repeater ? Put one outside of the repeater and call it good. Or if you just want to refresh some text dont use an update panel, use a call back with some client side script to set the dom element. Check out this http://encosia.com/2007/07/11/why-aspnet-ajax-updatepanels-are-dangerous/
Neither of those is proper anyway. You shouldn't be trying to directly reference a control that's contained within the ItemTemplate.
If you want to modify those Labels at runtime, you should be using OnItemDataBound and FindControl. To "find" the Label in the UpdatePanel, you'll need to use UpdatePanel.ContentTemplateContainer.FindControl().