Object reference not set to an instance of an object in ASP.net

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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:

C++

Line 68:             TextBox txtEmail = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtEmail");
Line 69:             con.Open();
Line 70:             SqlCommand cmd = new SqlCommand("update Employee_Details set PrinterID='" + txtPrinterID.Text + "',Name='" + txtName.Text + "',Department='" + txtDepartment.Text + "',Description='" + txtDescription.Text + "',Email='" + txtEmail.Text + "' where Id=" + Id, con);
Line 71:             cmd.ExecuteNonQuery();
Line 72:             con.Close();<pre>

line 70 is in red.

Posted 21-Oct-12 16:44pm

Member 9490803

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Bun Leap_kh 21-Oct-12 23:15pm

Please check with your 'con' object first. Did you initialize it?

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AshishChaudha · Answer 1 · 2012-10-21T18:41:00

Solution 2

First of all I would like to suggest that Always make a habbit to use Parameterized Query. Regarding to your issue it may possible that CONNECTION is not established or the parameter ID is null.

Thanks

Posted 21-Oct-12 18:41pm

AshishChaudha

Abhinav S · Answer 2 · 2012-10-21T17:35:00

This error normally occurs when you are trying to access a member of an object that is null.
Try debugging your code and tracing out the object that is null.

One cause could be this line returns null - gvDetails.Rows[e.RowIndex].FindControl("txtEmail").
When you try and access the .Text property of this object you could be getting an error.

Member 9490803 · Answer 3 · 2012-10-21T21:38:00

C#

protected void gvDetails_RowUpdating(object sender, GridViewUpdateEventArgs e)
       {
           int Id = Convert.ToInt32(gvDetails.DataKeys[e.RowIndex].Value.ToString());
           TextBox txtPrinterID = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtPrinterID");
           string username = gvDetails.DataKeys[e.RowIndex].Values["Username"].ToString();
           TextBox txtName = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtName");
           TextBox txtDepartment = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtDepartment");
           TextBox txtDescription = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtDescription");
           TextBox txtEmail = (TextBox)gvDetails.Rows[e.RowIndex].FindControl("txtEmail");
           con.Open();
           SqlCommand cmd = new SqlCommand("update Employee_Details set PrinterID='" + txtPrinterID.Text + "',Name='" + txtName.Text + "',Department='" + txtDepartment.Text + "',Description='" + txtDescription.Text + "',Email='" + txtEmail.Text + "' where Id=" + Id, con);
           cmd.ExecuteNonQuery();
           con.Close();
           lblresult.ForeColor = Color.Green;
           lblresult.Text = username + " Details Updated successfully";
           gvDetails.EditIndex = -1;
           BindEmployeeDetails();
       }
       protected void gvDetails_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
       {
           gvDetails.EditIndex = -1;
           BindEmployeeDetails();
       }<pre>

my code is this. is it wrong?

Object reference not set to an instance of an object in ASP.net

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