Value entered into Textbox inside datalist is not assigning

Question

0.00/5 (No votes)

See more:

I get the following exceptions at Button18_click:

An exception of type 'System.NullReferenceException' occurred in App_Web_cdebfrfo.dll but was not handled in user code

Additional information: Object reference not set to an instance of an object

My code for textbox inside a datalist:

XML

<asp:TextBox Id="TB2" runat="server" Text="" Width="24" OnTextChanged="TB2_TextChanged" MaxLength="6"
Height="12"     BorderStyle="Groove">
</asp:TextBox>

<asp:Button ID="Button18" runat="server" ForeColor="White"  onclick="Button18_Click"
         BackColor="Teal" Font-Size="small"
 style="z-index: 1;font-family:Sans-Serif; height:22px;  font-weight:900; "
 Text="Add to cart" />

C#

protected void Button18_Click(object sender, EventArgs e)
   {
       string ss = Convert.ToString(Datalist1.FindControl("TB2").ToString());
  }

Posted 21-Sep-13 6:00am

S.Rajendran from Coimbatore

Updated 21-Sep-13 6:08am

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

ZurdoDev · Answer 1 · 2013-09-21T17:31:00

Solution 1

It can't find the TB2 control. I would recommend putting breakpoint and debug it. Perhaps you have an additional control that is the parent of the textbox. FindControl does not go all the way down the tree. So, you may need to do Datalist1.Controls[0].FindControl("TB2") for example. Debug it and you should be able to find it.

Posted 21-Sep-13 17:31pm

ZurdoDev

Comments

S.Rajendran from Coimbatore 21-Sep-13 23:49pm

I entered '5' with 'TB2'.
With a break point to verify at string 'ss' I used like this:
string ss=Convert.ToString(Datalist1.Controls[0].FindControl("TB2"));
The result for string 'ss' is "" instead of '5'.

ZurdoDev 21-Sep-13 23:53pm

You'll need to examine Datalist1.Controls collection to see what is what and where your control is.

S.Rajendran from Coimbatore 21-Sep-13 23:59pm

Hereunder is code for my datalist1:

<asp:DataList ID="Datalist1" runat="server" DataKeyField="item_code" RepeatDirection="Horizontal"
RepeatLayout="Table">
<HeaderTemplate>
</HeaderTemplate>
<itemtemplate>
Item code:
<asp:Label Id="Itmcodelbl" runat="server" Text='<%#Eval("item_code") %>'>

 
Item Name:
<asp:Label Id="Itmnamelbl" runat="server" Text='<%#Eval("item_name") %>'>

 
Particulars:
 
<asp:TextBox Id="TB1" runat="server" Text='<%#Eval("item_desc") %>'
Height="94" ReadOnly="true" TextMode="MultiLine" BorderStyle="None">

 

<asp:Image ID="imgEmp" runat="server" Width="100px" Height="120px" ImageUrl='<%# Bind("Photopath","~/photo/{0}") %>' style="padding-left:40px; border-color:Green; border-left-style:groove; border-width:thin"/> 
Buy :
<asp:TextBox Id="TB2" runat="server" Text="" Width="24" OnTextChanged="TB2_TextChanged" MaxLength="6" AutoPostBack="true"
Height="12" BorderStyle="Groove">

<asp:Button ID="Button18" runat="server" ForeColor="White" onclick="Button18_Click"
BackColor="Teal" Font-Size="small"
style="z-index: 1;font-family:Sans-Serif; height:22px; font-weight:900; "
Text="Add to cart" />

ZurdoDev 24-Sep-13 21:03pm

Where's your item template?

pamod singh 25-Jul-14 6:12am

<asp:DataList ID="Datalist1" runat="server" DataKeyField="item_code" RepeatDirection="Horizontal"
RepeatLayout="Table">
<HeaderTemplate>
</HeaderTemplate>

Item code:
<asp:Label Id="Itmcodelbl" runat="server" Text='<%#Eval("item_code") %>'>

 
Item Name:
<asp:Label Id="Itmnamelbl" runat="server" Text='<%#Eval("item_name") %>'>

 
Particulars:
 
<asp:TextBox Id="TB1" runat="server" Text='<%#Eval("item_desc") %>'
Height="94" ReadOnly="true" TextMode="MultiLine" BorderStyle="None">

 

<asp:Image ID="imgEmp" runat="server" Width="100px" Height="120px" ImageUrl='<%# Bind("Photopath","~/photo/{0}") %>' style="padding-left:40px; border-color:Green; border-left-style:groove; border-width:thin"/> 
Buy :
<asp:TextBox Id="TB2" runat="server" Text="" Width="24" OnTextChanged="TB2_TextChanged" MaxLength="6" AutoPostBack="true"
Height="12" BorderStyle="Groove">

<asp:Button ID="Button18" runat="server" ForeColor="White" onclick="Button18_Click"
BackColor="Teal" Font-Size="small"
style="z-index: 1;font-family:Sans-Serif; height:22px; font-weight:900; "
Text="Add to cart" />