User Control not Adding to TableLayoutPanel at Runtime

Question

I have a TableLayoutPanel on a form which has 8 columns and 8 rows. I'm trying to populate this table from a list of a user controls which each contain three labels. When I run the app, I can see it has been populated, but looking at the actual form, it is empty.

I've tried replacing the control with just a label, and they show up fine, it's just when I try to use the user control that it doesn't work.

This code runs in the Load method and generates a list of GridSquareModel, which is used to populate the user control. Each model has an X and Y position which relates to their cell on the table panel.

var startup = new StartupForm();
if (startup.ShowDialog() == DialogResult.OK)
{
    var grid = new List<GridSquareModel>();
    for (int i = 0; i < 64; i++)
    {
        Position pos = new Position();
        pos.X = i % 8;
        pos.Y = i / 8;
        grid.Add(new GridSquareModel(pos));
    }

    RenderGrid(grid);
}
else
{
    Application.Exit();
}

This method generates a GridSquareControl for every GridSquareModel in the list. The X and Y value in the position determines which cell they are added to.

private void RenderGrid(List<GridSquareModel> grid)
{
    UIGrid.Clear();
    GridTable.Controls.Clear();

    foreach (var item in grid)
    {
        var control = new GridSquareControl(item)
        {
            Dock = DockStyle.Fill
        };
        GridTable.Controls.Add(control, item.Position.X, item.Position.Y);
        //GridTable.Controls.Add(new Label
        //{
        //    Text = "TEST"
        //}, item.Position.X + 1, item.Position.Y + 1);
    }

}

I have commented my attempt to replace the GridSquareModel with a Label, which worked. This should produce a table containing 64 controls but once it is loaded the table appears empty.

If Label works and GridSquareControl does not, I would suspect that control itself. For example is it's Visible set to true? It is hard to investigate/help when we do not know exactly how is GridSquareControl implemented. — Stano Peťko

TobyMeehan TobyMeehan · Accepted Answer · 2019-09-20T15:13:00

I'm an idiot. I created a constructor for GridSquareControl but it did not include the InitializeComponent method, so obviously it was not rendered. All is working as expected now.

User Control not Adding to TableLayoutPanel at Runtime

1 Answers