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ASP.NET - Error : Object reference not set to an instance of an object  ASP.NET - Error : Object reference not set to an instance of an object

Asked By vimalkumar panneerselvam
22-Nov-10 10:08 AM

Hi am trying to get the records from the gridivew which is checked using checkbox in datatable and passing that data table to a session to take to another page . but when am tryng to execute the code the above mentioned error shows
in the line

dataRow[i] = GridView1.SelectedRow.Cells[i2].Text;

Can anyone help me to sort out thz problem

protected void Button2008_Click(object sender, EventArgs e)

{

try

{

//DataTable dtMain =

//copy the schema of source table

DataTable dtClone = new DataTable();

dtClone.Columns.Add("Email_address");

DataRow dataRow;

dataRow = dtClone.NewRow();

int i2 = 1;

foreach (GridViewRow gv in GridView1.Rows)

{

CheckBox chk = gv.FindControl("chkSelect") as CheckBox;

HiddenField hdValue = gv.FindControl("hdValue") as HiddenField;

if (chk.Checked)

{

for (int i = 0; i < dataRow.Table.Columns.Count; i++)

{

dataRow[i] = GridView1.SelectedRow.Cells[i2].Text;

i2++;

}

dtClone.Rows.Add(dataRow);

}

}

HttpContext.Current.Session["keys"]=dtClone;

}

catch

{

FillClientInGrid();

}

Response.Redirect("About.aspx", true);

}

  Danasegarane Arunachalam replied to vimalkumar panneerselvam
22-Nov-10 10:13 AM
In which line you get the error ?
  vimalkumar panneerselvam replied to Danasegarane Arunachalam
22-Nov-10 10:16 AM
dataRow[i] = GridView1.SelectedRow.Cells[i2].Text;
  Parag Satpute replied to vimalkumar panneerselvam
22-Nov-10 10:17 AM
Look out for the common mistakes because of which the "Object reference not set to an instance of an object" error is generated on the below link,

http://forums.aspfree.com/net-development-11/common-causes-of-object-reference-not-set-to-an-instance-45799.html
  Peter Bromberg replied to vimalkumar panneerselvam
22-Nov-10 10:18 AM
Since you are starting out with i2 =1, I suspect that you are simply going farther than the number of cells in the Gridview Row.

dataRow[i] = GridView1.SelectedRow.Cells[i2].Text;

i2++;


If you go into debug/ Exceptions and check "Common Language Runtime Exceptions" the debugger will break at the exact instance in the loop and you can check the values of your variables there.
  vimalkumar panneerselvam replied to Peter Bromberg
22-Nov-10 10:41 AM
Hi  Peter,

Thx for you suggestion.

Can i hav any sample code for the below requirement.

I have a gridivew with checkbox when the user selects the checkbox the records from the datasource should pass to the datatable and tat datatable should be assigned to a session to take to another webpage .


am using to bind the gridview like thz currently:
GridView1.DataSource = pds;
GridView1.DataBind();


Thanx in advance
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