Dynamically Created Hierarchical Grid

[Adam Nelson]

I have a scenario in which a user may select from a number of predefined queries which loads a RadGrid. The grid is generated dynamically as the columns may vary from query to query. This is all working until I tried adding DetailTables for the MasterTableView. I tried to recreate my issue by following examples in documentation and it all worked, until I added a button that would simulate the selection of a query. If the grid is added to the control collection initially without any DetailTables it seems like it is impossible to add one later. Is this by design?

Here is the code for my sample application.

protected void Page_Init(object sender, System.EventArgs e)
{
    PopulateGridOnPageInit();
}

private bool LoadGrid()
{
    //Hidden field is set true when "Load Grid" button is clicked
    string loadGrid = Request.Form.Get(this.uxHiddenField_LoadGrid.UniqueID);
    if (!string.IsNullOrEmpty(loadGrid))
    {
        return Boolean.Parse(loadGrid);
    }
    else
    {
        return false;
    }
}

private void PopulateGridOnPageInit()
{
    RadGrid radGrid = new RadGrid();
    radGrid.ID = RadGridId;

    if (!LoadGrid())
    {
        radGrid.Visible = false;
        // Add the Grid to the page
        uxPlaceHolder.Controls.Add(radGrid);
        return;
    }
    // Set properties
    radGrid.Skin = "Vista";
    radGrid.PageSize = 25;
    radGrid.AllowPaging = true;
    radGrid.AllowCustomPaging = true;
    radGrid.AllowSorting = true;
    radGrid.MasterTableView.AllowCustomSorting = true;
    radGrid.MasterTableView.EnableColumnsViewState = false;
    radGrid.PagerStyle.Mode = GridPagerMode.NextPrevAndNumeric;

    radGrid.ClientSettings.Selecting.AllowRowSelect = true;
    radGrid.ClientSettings.Selecting.EnableDragToSelectRows = false;
    radGrid.ClientSettings.Resizing.AllowColumnResize = false;
    radGrid.ClientSettings.Resizing.ClipCellContentOnResize = false;
    radGrid.ClientSettings.Resizing.EnableRealTimeResize = false;
    radGrid.ClientSettings.ReorderColumnsOnClient = false;
    radGrid.ClientSettings.AllowColumnsReorder = false;
    radGrid.ClientSettings.ColumnsReorderMethod = GridClientSettings.GridColumnsReorderMethod.Reorder;

    radGrid.ShowGroupPanel = false;
    radGrid.GroupingEnabled = false;
    radGrid.GroupPanel.Visible = false;
    radGrid.ShowFooter = false;
    radGrid.MasterTableView.ShowFooter = false;

    // Selecting multiple rows (client-side)
    radGrid.AllowMultiRowSelection = true;
    GridClientSelectColumn gridClientSelectColumn = new GridClientSelectColumn();
    gridClientSelectColumn.ItemStyle.Width = Unit.Percentage(1);
    radGrid.Columns.Add(gridClientSelectColumn);

    // Build the columns dynamically
    radGrid.AutoGenerateColumns = false;

    GridBoundColumn column = new GridBoundColumn();
    column.DataField = "ID";
    column.HeaderText = "Customer Identifier";
    radGrid.Columns.Add(column);
    column = new GridBoundColumn();
    column.DataField = "Name";
    column.HeaderText = "Name";
    radGrid.Columns.Add(column);
    column = new GridBoundColumn();
    column.DataField = "Company";
    column.HeaderText = "Company";
    radGrid.Columns.Add(column);
    GridTableView childTable = new GridTableView(radGrid);
    childTable.Width = Unit.Percentage(100);
    childTable.DataMember = "CustomerID";
    column = new GridBoundColumn();
    column.DataField = "ID";
    column.HeaderText = "Order Identifier";
    childTable.Columns.Add(column);
    column = new GridBoundColumn();
    column.DataField = "OrderDate";
    column.HeaderText = "Order Date";
    childTable.Columns.Add(column);
    column = new GridBoundColumn();
    column.DataField = "Cost";
    column.HeaderText = "Cost";
    childTable.Columns.Add(column);
    radGrid.MasterTableView.DetailTables.Add(childTable);

    // Wire up the method that will get the grid data
    radGrid.NeedDataSource += new GridNeedDataSourceEventHandler(radGrid_NeedDataSource);

    radGrid.DetailTableDataBind += new GridDetailTableDataBindEventHandler(radGrid_DetailTableDataBind);

    // Set the key for client side selection
    radGrid.MasterTableView.ClientDataKeyNames = new string[] { "ID" };

    // Set the key for server side selection
    radGrid.MasterTableView.DataKeyNames = new string[] { "ID" };

    // Add the Grid to the page
    uxPlaceHolder.Controls.Add(radGrid);
}

protected void radGrid_NeedDataSource(object source, GridNeedDataSourceEventArgs e)
{
    if (!e.IsFromDetailTable)
    {
        // Get the rad grid
        RadGrid radGrid = (RadGrid)source;

        // Bind it to the Grid
        radGrid.DataSource = this.Customers;

        // Set the count
        radGrid.VirtualItemCount = this.Customers.Count;
    }
}

protected void radGrid_DetailTableDataBind(object source, GridDetailTableDataBindEventArgs e)
{
    GridDataItem dataItem = e.DetailTableView.ParentItem;
    switch (e.DetailTableView.DataMember)
    {
        case "CustomerID":
            List<Order> orders = GetOrdersForCustomer((int)dataItem.GetDataKeyValue("ID"));
            e.DetailTableView.DataSource = orders;
            e.DetailTableView.VirtualItemCount = orders.Count;
            break;
        default:
            break;
    }
}

Any thoughts or advice would be very appreciated.

Thanks,

Adam

[Iana Tsolova]

Hi Adam,

Please try modifying your code as shown below and check if it makes any difference:

if (!LoadGrid())
{
    radGrid.Style["display"] = "none";
    // Add the Grid to the page
    //uxPlaceHolder.Controls.Add(radGrid);
    //return;
}

Find more about RadGrid Visible/ conventions here.

Let me know how it goes.

Kind regards,
Iana
the Telerik team

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