Object reference not set to an instance of an object

Question

0.00/5 (No votes)

See more:

I develop Master-Child form.
On child form, I put a DetailsView control.
I write a code at Page Load.

C#

DataTable dt = new DataTable();
dt = vm.Gridfill(vm);
if (dt.Rows.Count > 0)
{
    DetailsView1.DataSource = vm.Gridfill(vm);
    DetailsView1.DataBind();
}
else
{
    DetailsView1.ChangeMode(DetailsViewMode.Insert);
}

I got error...

C#

Server Error in '/' Application.
 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:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:
[NullReferenceException: Object reference not set to an instance of an object.]
   AjaxControlToolkit.MaskedEditExtender.OnLoad(EventArgs e) +135
   System.Web.UI.Control.LoadRecursive() +47
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Control.AddedControl(Control control, Int32 index) +318
   System.Web.UI.ControlCollection.Add(Control child) +146
   System.Web.UI.WebControls.CellControlCollection.Add(Control child) +34
   System.Web.UI.ControlCollection.AddAt(Int32 index, Control child) +33
   System.Web.UI.WebControls.CellControlCollection.AddAt(Int32 index, Control child) +40

Posted 25-Sep-13 20:41pm

dhiraj mane

Updated 25-Sep-13 20:54pm

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

v2

Add a Solution

Comments

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 26-Sep-13 2:51am

Can you please debug and let us know on which line exactly it is throwing the Exception?

member 8888995 26-Sep-13 2:51am

Hi ,
Can you plaese specify details about this 'vm.Gridfill(vm)'.

--
Thanks

dhiraj mane 26-Sep-13 3:24am

that's my class object (VehicleMaster vm = new VehicleMaster()) in that code is
public DataTable TableFill1(string Query)
{
DataTable dt = new DataTable();
try
{
if (con.State != ConnectionState.Open)
{
con.Open();
}
SqlDataReader dr;
cmd = new SqlCommand(Query, con);
cmd.CommandType = CommandType.StoredProcedure;
dr = cmd.ExecuteReader();
dt.Load(dr);
}
catch (Exception)
{
throw;
}
return dt;
}

3 solutions

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)

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) · Answer 1 · 2013-09-25T20:57:00

Solution 1

As you are using DataBind Controls, make sure you are checking IsPostBack Property[^] on Page_Load.

C#

private void Page_Load()
{
    if (!IsPostBack)
    {
        // All your Binding codes here.
    }
}

Posted 25-Sep-13 20:57pm

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

Anil Avhad [IND] · Answer 2 · 2013-09-25T21:26:00

Solution 2

Hi,

Make sure your code is not returning Null Value from this code "vm.Gridfill(vm);".

Posted 25-Sep-13 21:26pm

Anil Avhad [IND]

member 8888995 · Answer 3 · 2013-09-25T23:03:00

Solution 3

Hi Mr. Mane ,
what is type of vm that you are passing as argument to this method. It seems incorrect that you are invoking this method as vm.Gridfill() and passing vm as argument to it? The method that you illustrated here 'TableFill1()' takes string type argument. This is not correct and it's confusing.

--
Thanks

Posted 25-Sep-13 23:03pm

member 8888995

Comments

dhiraj mane 26-Sep-13 5:49am

That problem is solve