Question

I would like to send a control to back of its container. Regardless some other controls are created and removed from the same container, I dont want this control to loose its position.

I dont have any better way to achieve this :

// Force this control to stay back 
private void panel1_ControlAdded(object sender, ControlEventArgs e) 
{
    pictureBox1.SendToBack(); 
}

It looks overkill to me. Is it a better way to achieve this ?

EDIT:

I am told that controls.add put controls in front by default. I cannot reproduce this behavior, or I miss the point somewhere. Here is what I tried :

using System;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsFormsApplication4
{
    public partial class Form1 : Form
    {
        System.Windows.Forms.Button button1;

        public Form1() { InitializeComponent(); }

        void InitializeComponent()
        {
            this.button1 = new System.Windows.Forms.Button();
            this.pictureBox1 = new System.Windows.Forms.PictureBox();
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
            this.SuspendLayout();
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(225, 182);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(139, 39);
            this.button1.TabIndex = 0;
            this.button1.Text = "button1";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // pictureBox1
            // 
            this.pictureBox1.Image = global::WindowsFormsApplication4.Properties.Resources.Tulips;
            this.pictureBox1.Location = new System.Drawing.Point(36, 26);
            this.pictureBox1.Name = "pictureBox1";
            this.pictureBox1.Size = new System.Drawing.Size(299, 175);
            this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
            this.pictureBox1.TabIndex = 1;
            this.pictureBox1.TabStop = false;
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(376, 233);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.pictureBox1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
            this.ResumeLayout(false);

        }

        private PictureBox pictureBox1;

        Point xy;

        // Add a button or anything else
        private void button1_Click(object sender, EventArgs e)
        {
            var ctl = new Button();
            ctl.Location = xy;

            this.Controls.Add(ctl);

            xy.Offset(10, 10);
        }

        // First of all, send the picture box to back
        private void Form1_Load(object sender, EventArgs e)
        {
            pictureBox1.SendToBack();
        }
    }
}

So as you can notice, as I hit button1 several times, the newly added buttons (can replaced by textboxes…) goes behind the picturebox that has been sent to back in the Load event. So I definitely cannot rely on Control.Add supposed default behavior.

Answer 1

As this trick seems to do its job fine after some days of tests, I feel no need to dig further.

// Force this control to stay back  
private void panel1_ControlAdded(object sender, ControlEventArgs e)  
{ 
    pictureBox1.SendToBack();  
}

However, I still wonder why Control.Add does not behaves the way it should.