WinForm：控件不会添加到面板中

Question

On a WinForms, I'm trying to add a control (here a simple label) to a panel each time I click a button. The UI looks like this:

when I first click the button, I got this (what I expect!):

but, after a second, a third, etc. click, nothing more happens; no labels are added anymore :(

However, I can see them in the list of controls when I'm in debug mode:

Here's my code (only the interesting stuff):

public partial class GestionPateFeuilletee : Form
{
    private List<Label> listeTours = new List<Label>();

    public GestionPateFeuilletee()
    {
        InitializeComponent();
    }

    private void boutonAjouterTour_Click(object sender, EventArgs e)
    {
        Point coordDepart = new Point(10, 160);
        int tabIndexDepart = 5;

        listeTours.Add(new Label());
        listeTours.Last().Name = "labelTour" + (listeTours.Count());
        listeTours.Last().Location = new System.Drawing.Point(coordDepart.X, coordDepart.Y + 30);
        listeTours.Last().TabIndex = tabIndexDepart + 1;
        listeTours.Last().Text = "labelTour" + (listeTours.Count());

        this.panelDescription.Controls.Add(listeTours.Last());
    }
}

Any idea? And yes, I'm a beginner with WinForms... Thanks!

Answer 1

Your panel height is fixed. Your controls are getting added to the panel. However they are getting hidden in the panel because of the panel height. You can either increase the panel height or put a vertical scroll in the panel / form to have the labels visible.

Also define the Y location based on the no. of labels

listeTours.Last().Location = new System.Drawing.Point(coordDepart.X, coordDepart.Y + ((listeTours.Count() + 1) * 30));