Question

I’m having a problem using custom components at runtime.
I have this custom FlowLayoutPanel component:

 public partial class UserControl1 : System.Windows.Forms.FlowLayoutPanel
{

    [Browsable(false)]
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.ExStyle |= 0x20;
            return cp;
        }
    }
    protected override void OnPaintBackground(PaintEventArgs e){}

    public UserControl1(){}
}

it has nothing complicated. All it does is making the background transparent.

I added this component to my Toolbox using it’s dll and it works perfectly fine when I drag and drop it to my Form. The problem is, I can’t add it programmatically at runtime.

When I run the code below it should draw the picture on top of my custom FlowLayoutControl.
But unfortunately it does nothing.

The custom component is under the WindowsFormsControlLibrary1 namespace.

 namespace MyFilm_v2._0
 {
  public partial class Form1 : Form
  {

    public Form1()
    {
        InitializeComponent();

        UserControl1 test = new UserControl1();
        test.BackColor = Color.Transparent;
        test.Location = new Point(0, 110);
        test.Width = 660;
        test.Height = 478;

        PictureBox b = new PictureBox();
        b.Location = new Point(100, 100);
        b.Width = 320;
        b.Height = 475;
        b.Image = Properties.Resources.movie;
        this.Controls.Add(b);
        //this.customScrollbar1.Minimum = 0;
        //this.customScrollbar1.Maximum = test.DisplayRectangle.Height;
        //this.customScrollbar1.LargeChange = customScrollbar1.Maximum / customScrollbar1.Height + test.Height;
        //this.customScrollbar1.SmallChange = 15;//when click the arrows
        //this.customScrollbar1.Value = Math.Abs(test.AutoScrollPosition.Y);
    }

….

Answer 1

You adding picturebox to your test controls, but you not adding test to forms controls

public Form1()
{
    InitializeComponent();

    UserControl1 test = new UserControl1();
    test.BackColor = Color.Transparent;
    test.Location = new Point(0, 110);
    test.Width = 660;
    test.Height = 478;

    PictureBox b = new PictureBox();
    b.Location = new Point(100, 100);
    b.Width = 320;
    b.Height = 475;
    b.Image = Properties.Resources.movie;
    test.Controls.Add(b);
    this.Controls.Add(test);//<- here
}