GridView: CurrentRowChanged Event

[Gopal]

hello,
I am manually loading the GridView and in CurrentRowChanged event of the gridView i am trying to fill the set of textboxes and label control with data present in the selected row of the  GridView.
Here are the codes:

1. manually Loading GridView data in a method
 private void loadAllUsers()
        {
          
            var obj = _dataAccess.GetAllMembers();
            if (obj != null && obj.Count > 0)
            {
 
                gvListUsers.Visible = true;
 
                gvListUsers.Columns.Clear();
                gvListUsers.AutoGenerateColumns = false;
                gvListUsers.MultiSelect = false;
                gvListUsers.EnableGrouping = true;
                gvListUsers.EnableCustomGrouping = true;                
                gvListUsers.ShowGroupedColumns = true;
                
 
                gvListUsers.DataSource = obj;
 
                var textBoxColumn = new GridViewTextBoxColumn();
                textBoxColumn.Name = "TextBoxColumn";
                textBoxColumn.HeaderText = "ID";
                textBoxColumn.FieldName = "MembershipID";
                textBoxColumn.Width = 50;
                gvListUsers.MasterTemplate.Columns.Add(textBoxColumn);
 
 
                var txtColumnUsername = new GridViewTextBoxColumn();
                txtColumnUsername.Name = "txtBoxColumnUsername";
                txtColumnUsername.HeaderText = "UserName";
                txtColumnUsername.FieldName = "Username";
                txtColumnUsername.Width = 120;
                gvListUsers.MasterTemplate.Columns.Add(txtColumnUsername);
                             
                var textBoxColumnFirstname = new GridViewTextBoxColumn();
                textBoxColumnFirstname.Name = "TextBoxColumnFirstname";
                textBoxColumnFirstname.HeaderText = "Firstname";
                textBoxColumnFirstname.FieldName = "FirstName";
                textBoxColumnFirstname.Width = 120;
                gvListUsers.MasterTemplate.Columns.Add(textBoxColumnFirstname);
 
                var textBoxColumnMiddlename = new GridViewTextBoxColumn();
                textBoxColumnMiddlename.Name = "TextBoxColumnMiddlename";
                textBoxColumnMiddlename.HeaderText = "Middlename";
                textBoxColumnMiddlename.FieldName = "MiddleName";
                textBoxColumnMiddlename.Width = 120;
                gvListUsers.MasterTemplate.Columns.Add(textBoxColumnMiddlename);
 
                var textBoxColumnLastName = new GridViewTextBoxColumn();
                textBoxColumnLastName.Name = "TextBoxColumnLastName";
                textBoxColumnLastName.HeaderText = "Lastname";
                textBoxColumnLastName.FieldName = "LastName";
                textBoxColumnLastName.Width = 120;
                gvListUsers.MasterTemplate.Columns.Add(textBoxColumnLastName);
 
                var textBoxColumnIsActive = new GridViewTextBoxColumn();
                textBoxColumnIsActive.Name = "TextBoxColumnIsActive";
                textBoxColumnIsActive.HeaderText = "Active";
                textBoxColumnIsActive.FieldName = "IsActive";
                textBoxColumnIsActive.Width = 100;
                gvListUsers.MasterTemplate.Columns.Add(textBoxColumnIsActive);
                //column formating
 
               
            }
            else
            {
                gvListUsers.Visible = false;
            }
        }
2. CurrentRowChanged Event: using this event i am assigning the currentrow data of gridview to different textboxes and label
control.
 private void gvListUsers_CurrentRowChanged(object sender, CurrentRowChangedEventArgs e)
        {
            UpdateInfo(this.gvListUsers.CurrentRow);
        }
 
        private void UpdateInfo(GridViewRowInfo currentRow)
        {
            if (currentRow != null && !(currentRow is GridViewNewRowInfo))
            {
		//gettting error "Object reference not set to an instance of an object."
                this.lblMembershipID.Text = this.GetSafeString(currentRow.Cells["MembershipID"].Value);
		this.txtUsername.Text = this.GetSafeString(currentRow.Cells["Username"].Value);
            }
        }
3.
	private string GetSafeString(object value)
        {
            if (value == null)
            {
                return string.Empty;
            }
            return value.ToString();
        }
4. i am getting "object reference not set to an instance of an object" error when am assigning currentrow
data to the label control and for textbox too. I am unable to track it why i am getting this error.
Kindly suggest me what can be done to resolve this issue.
Thanks!!!!

[Boryana]

Hi Gopal,

Thank you for contacting us.

Would you please change the MemberID to TextBoxColumn and UserName to txtBoxColumnUsername in the UpdateInfo method? The two lines should look like this:

this.lblMembershipID.Text = this.GetSafeString(currentRow.Cells["TextBoxColumn"].Value);
this.txtUsername.Text = this.GetSafeString(currentRow.Cells["txtBoxColumnUsername"].Value);

The exception is thrown because you are attempting to find a cell using the HeaderText of the column, not its Name. A bit aside, I would like to point out that it is better to set the DataSource property after you have added all columns to the MasterTemplate.

I hope this helps. Let me know if you have further queries.

Kind regards,
Boryana
the Telerik team

[Gopal]

Boryana,
Thanks for the response.! Issued resolved. :)