Picture Box image flickering

Question

I have a panel containing multiple picturebox.

I want to give users the option of selecting any part of any picturebox.

The user will select it by mouse.

I want to draw a semi-transparent rectangle on the picturebox while the mouse move as per the selection.

The code is working fine, but the rectangle is flickering. I want to stop the flickering.

I tried double buffer using how to stop flickering C# winforms

Also, added Invalide using How to force graphic to be redrawn with the invalidate method

But not working. Please help.

My Code:

private Brush selectionBrush = new SolidBrush(Color.FromArgb(70, 76, 255, 0));

private void Picture_MouseMove(object sender, MouseEventArgs e)
{
    if (e.Button != MouseButtons.Left) return;

    PictureBox pb = (PictureBox)(sender);

    Point tempEndPoint = e.Location;
    Rect.Location = new Point(
        Math.Min(RecStartpoint.X, tempEndPoint.X),
        Math.Min(RecStartpoint.Y, tempEndPoint.Y));
    Rect.Size = new Size(
        Math.Abs(RecStartpoint.X - tempEndPoint.X),
        Math.Abs(RecStartpoint.Y - tempEndPoint.Y));

    pb.CreateGraphics().FillRectangle(selectionBrush, Rect);
    pb.Invalidate(Rect);
}

Answer 1

This does not address the PictureBox, but maybe helps.

First I replaced the PictureBox with Panel which can also be used to draw pictures. Next I activated double buffering:

somewhere in the namespace add this class:

class DoubleBufferedPanel : Panel 
{ 
    public DoubleBufferedPanel() : base() 
    { 
        DoubleBuffered = true; 
    } 
 }

and then replace in Form1.Designer.cs all "System.Windows.Forms.Panel" with "DoubleBufferedPanel".

this works fine in many of my graphical applications.

Answer 2

You indicate the Double Buffering solution doesn't work for you, did you find out why? Because the following custom control draws a sizable rectangle on the picturebox without the flicker:

public class TryDoubleBufferAgain : PictureBox
{
    public TryDoubleBufferAgain()
    {
        this.DoubleBuffered = true;
        this.SetStyle(ControlStyles.AllPaintingInWmPaint, true);
        this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true);
        this.UpdateStyles();
    }
    protected override void OnMouseMove(MouseEventArgs e)
    {
        this.Refresh();
        base.OnMouseMove(e);
    }
    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        // Edit below to actually  draw a usefull rectangle
        e.Graphics.DrawRectangle(System.Drawing.Pens.Red, new System.Drawing.Rectangle(0, 0, Cursor.Position.X, Cursor.Position.Y));
    }
}