Insert & Update code is not working in ASP.NET

Question

I am getting "Object reference not set to an instance of an object" error while inserting/updating data into a sql server database from gridview . Anybody please help .

protected void GridAllStore_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        storelocatorDataSetTableAdapters.storedbTableAdapter tastoreInsert = new storelocatorDataSetTableAdapters.storedbTableAdapter();
        if (e.CommandName.Equals("Insert"))
        {
            TextBox txtNewName = new TextBox();
            TextBox txtNewContact = new TextBox();
            TextBox txtNewAddress = new TextBox();
            txtNewName = (TextBox)GridAllStore.FooterRow.FindControl("txtNewName");
            txtNewContact = (TextBox)GridAllStore.FooterRow.FindControl("txtNewContact");
            txtNewAddress = (TextBox)GridAllStore.FooterRow.FindControl("txtNewAddress");
            tastore.Insert(txtNewName.Text, txtNewContact.Text, txtNewAddress.Text);    
            FillGrid();          
        }
    }

Here is the error message:

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 107: txtNewContact = (TextBox)GridAllStore.FooterRow.FindControl("txtNewContact");
Line 108: txtNewAddress = (TextBox)GridAllStore.FooterRow.FindControl("txtNewAddress");
Line 109: tastore.Insert(txtNewName.Text, txtNewContact.Text, txtNewAddress.Text);
Line 110: FillGrid();
Line 111: }

Source File: C:\Users\DELL\Documents\Visual Studio 2010\Projects\WebApplication1\WebApplication1\AdminPanel.aspx.cs Line: 109

Breakpoint the method and step through reviewing instances and their properties for nulls. Start on GridAllStore then FooterRow as the most likely. — Adam Houldsworth
– Adam Houldsworth, Commented Apr 24, 2012 at 7:09
Tastore could also be null and you seem to declare tastoreInsert and never use it. — Adam Houldsworth
– Adam Houldsworth, Commented Apr 24, 2012 at 7:26

Damith · Accepted Answer · 2012-04-24 07:46:58Z

1

FindControl can return null, when you access Text property of null object exception will throw. you can check null before access Text property.

        var txtNewNameTb = (TextBox)GridAllStore.FooterRow.FindControl("txtNewName");
        var txtNewContactTb = (TextBox)GridAllStore.FooterRow.FindControl("txtNewContact");
        var txtNewAddressTb = (TextBox)GridAllStore.FooterRow.FindControl("txtNewAddress");

        if (txtNewNameTb == null || txtNewContactTb == null || txtNewAddressTb  == null) { return; }

        if(tastore == null)  { return; }

        tastore.Insert(txtNewNameTb.Text, txtNewContactTb.Text, txtNewAddressTb.Text);    

        FillGrid();

In your ASPX FooterTemplate there should be a 3 Text Boxes like below.

<FooterTemplate> 
<asp:TextBox ID="txtNewName" runat="server" >
</asp:TextBox> 
<asp:TextBox ID="txtNewContact" runat="server" >
</asp:TextBox> 
<asp:TextBox ID="txtNewAddress" runat="server" >
</asp:TextBox> 
</FooterTemplate>

edited Apr 24, 2012 at 7:46

answered Apr 24, 2012 at 7:28

Damith

63.2k13 gold badges106 silver badges154 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Fahim Ahmed Over a year ago

It's giving me error in this line : var txtNewName = txtNewNameTb ? txtNewNameTb.Text : string.Empty; It says : Error 2 Cannot implicitly convert type 'System.Web.UI.WebControls.TextBox' to 'bool'

Mr Lister · Accepted Answer · 2012-04-24 07:25:57Z

1

The error message means tastore is null in line 109, so tastore needs to be initialised. You have confused yourself by writing tastoreInsert in the function header and tastore.Insert in the body.

Edit: Sorry, it could also mean that any of the three textboxes does not exist. FindControl returns null if the control is not found, so you'd need to look into those too. Debug!

edited Apr 24, 2012 at 7:25

answered Apr 24, 2012 at 7:12

Mr Lister

46.8k15 gold badges118 silver badges156 bronze badges

12 Comments

Adam Houldsworth Over a year ago

Tastore won't even exist so I'd guess that wouldn't compile.

Mr Lister Over a year ago

@AdamHouldsworth Yes it does! The error is a run-time error, so it must have compiled without error. That's why I said the OP is confusing himself with names like tastore and tastoreInsert.

Mr Lister Over a year ago

@FahimAhmed Where do you initialise tastore then? That part of the program isn't shown, and the error message means tastore is null.

Adam Houldsworth Over a year ago

I would first assume that it is a typo in the question. I know that the exception is a runtime one. We can only go off the code and stacktrace provided in which case my point stands. The code doesn't show tastore being declared.

Adam Houldsworth Over a year ago

@fahimahmed all I can advise is that you try what I suggested in the comments to your question. Something is null and your code is trying to use it, simply.

|

Pranav · Accepted Answer · 2012-04-24 07:41:14Z

0

use Convert.ToString(txtNewNameTb.Text)
it automatically converts NULL to empty string.

try like :-

tastore.Insert(Convert.ToString(txtNewName.Text),Convert.ToString( txtNewContact.Text), Convert.ToString(txtNewAddress.Text));

answered Apr 24, 2012 at 7:41

Pranav

8,9214 gold badges28 silver badges42 bronze badges

Collectives™ on Stack Overflow

Insert & Update code is not working in ASP.NET

3 Answers 3

1 Comment

12 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

12 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related