Adding CheckBox columns programmatically with Events

[Dan Harvey]

Hello,

I am having trouble adding "OnChecked" events to my GridTemplateColumns I am creating programmatically.

Here is the code I am using to create my columns (and the new column "RoleColumn"):

               public void DefineGridStructure()

            {

                var templateColumn = new GridTemplateColumn();

                templateColumn.UniqueName = "myColumn" + i;

                templateColumn.ItemTemplate = new RoleColumn("myColumn" + i);

  

                 // add the dynamically created columns to the grid

                dgLoginRequest.MasterTableView.Columns.AddAt(COLUMN_START_POS - 1, templateColumn);

            }

  

  

    public class RoleColumn : ITemplate
    {

  

        protected CheckBox roleCheckbox;

        private string _columnName;

  

        public RoleColumn(string columnName)

        {

            _columnName = columnName;

        }

  

        public void InstantiateIn(Control container)

        {

            roleCheckbox = new CheckBox { ID = "cbx" + _columnName };

            roleCheckbox.AutoPostBack = true;

            roleCheckbox.DataBinding += new EventHandler(roleCheckbox_DataBinding);

            container.Controls.Add(roleCheckbox);

        }

  

        private void roleCheckbox_DataBinding(object sender, EventArgs e)

        {

            var cBox = (CheckBox)sender;

            var container = (GridDataItem)cBox.NamingContainer;

            cBox.Checked = ((EntityUserRole)container.DataItem).Roles[0][_columnName];

        }

  

    }

Now when I call the DefineGridStructure routine I then bind a data source to my grid (the datasource is an ArrayList type which holds "Role" objects):

           public void BindDataGrid()

        {

            try

            {

                DefineGridStructure();

                dgLoginRequest.DataSource = DataSource;

                dgLoginRequest.DataBind();

            }

            catch (Exception ex)

            {

                throw;

            }

        }

    public

 

 

interface IRole

 

    {

 

 

        Int16 RoleID { get; set; }

 

 

 

        string RoleName { get; set; }

 

 

 

        Int16 OrderID { get; set; }

 

    }

I then capture the OnItemDataBoundEvent and add my event handler at this point;

            protected void dgLoginRequest_ItemDataBound(object sender, GridItemEventArgs e)

        {

            if (e.Item is GridDataItem)

            { 

                    var i = 0;

                foreach (Role role in Roles)

                {

                    var checkbox = (e.Item as GridDataItem)["myColumn" + i].Controls[0] as CheckBox;

                    checkbox.CheckedChanged += new EventHandler(cbxReader_CheckedChanged); 
                            i++;

                }

                  

            }

        }

However, when I click my checkboxes they do not fire the event (cbx_CheckedChanged).

What am I missing?

All I want to do is create a checkbox column for each role that I have in my Arraylist (currently 4).  And I want to be able to handle the "OnCheckedChanged" event in code whenever any of these checkboxes are checked.

Please help.  I have went through the documenation already - that's how i got this far.  A sample application would be appreciated.

Thanks,

[Antonio Stoilkov]

Hello Dan,

You could resolve your issue by setting the CheckBox control AutoPostBack property to true in order to successfully call the server-side CheckedChanged event as it is shown below.

foreach (Role role in Roles)
{
    var checkbox = (e.Item as GridDataItem)["myColumn" + i].Controls[0] as CheckBox;
    checkbox.CheckedChanged += new EventHandler(cbxReader_CheckedChanged);
    checkbox.AutoPostBack = true;
    i++;
}

All the best,
Antonio Stoilkov
the Telerik team