Adding PictureBoxes to TableLayoutPanel is very slow

Question

Hello guys I am adding PictureBoxes to TableLayoutPanel cells, but for 10x10 grid it takes like 10 seconds, which is too long. My code looks like this, could you tell me how can i improve it, so PictureBoxes will be added instantly? Here is how i do it:

 private void x10ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            tableLayoutPanel1.Controls.Clear();
            tableLayoutPanel1.ColumnStyles.Clear();
            tableLayoutPanel1.RowStyles.Clear();
            tableLayoutPanel1.ColumnCount = 10;
            tableLayoutPanel1.RowCount = 10;
            int sliderval = trackBar1.Value;
            //tableLayoutPanel1.Controls.Add(new PictureBox(),2,1);
            for (int i = 0; i < tableLayoutPanel1.RowCount; i++)
            {
                tableLayoutPanel1.RowStyles.Add(new System.Windows.Forms.RowStyle(System.Windows.Forms.SizeType.Percent, (100 / tableLayoutPanel1.RowCount)));
                for (int j = 0; j < tableLayoutPanel1.ColumnCount; j++)
                {
                    tableLayoutPanel1.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, (100 / tableLayoutPanel1.ColumnCount)));


                    PictureBox picture = new PictureBox
                    {
                        Name = "pictureBox" + i,
                        Size = new Size(49, 35),
                        Visible = true,

                        Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                | System.Windows.Forms.AnchorStyles.Left)
                | System.Windows.Forms.AnchorStyles.Right))),
                        BackColor = colors[random.Next(0, sliderval)],
                        TabIndex = 0,
                        TabStop = false
                    };
                    tableLayoutPanel1.Controls.Add(picture, j, i);
                    picture.Dock = DockStyle.Fill;
                    // picture.Margin = new Thickness(40, 16, 0, 0);
                    // picture.Padding = new Padding(0);         
                    picture.SizeMode = PictureBoxSizeMode.Normal;
                    picture.Margin = new Padding(0);
                }

            }
            AssignClickEvent();
        }

Answer 1

Take a look at this URL. It might be that your form requires repainting alm the time and sloes it down. Rather pause the painting. Do all your changes and then resume it. Less painting. http://www.c-sharpcorner.com/Forums/Thread/52/