Clear image on picturebox

Question

How can I clear draw image on picturebox? The following doesn't help me:

pictbox.Image = null;
pictbox.Invalidate();

Please help.

EDIT

private void pictbox_Paint(object sender, PaintEventArgs e) 
{ 
     Graphics g = e.Graphics; 
     vl.Draw(g, ref tran.realListForInsert); 
} 

public void Draw(Graphics g, ref List<double> arr) 
{ 
    g.DrawRectangle(new Pen(Brushes.Red, 3), nodeArr[Convert.ToInt32(templstName)].pict.Location.X, nodeArr[Convert.ToInt32(templstName)].pict.Location.Y, 25, 25); 
    g.DrawRectangle(new Pen(Brushes.Green, 3), nodeArr[Convert.ToInt32(templstArgName)].pict.Location.X, nodeArr[Convert.ToInt32(templstArgName)].pict.Location.Y, 25, 25); 
    nodeArr[Convert.ToInt32(templstName)].text.Text = arr[Convert.ToInt32(templstArgName)].ToString(); 
    arr[Convert.ToInt32(templstName)] = arr[Convert.ToInt32(templstArgName)]; 
} 

Answer 1

You need the following:

pictbox.Image = null;
pictbox.update();

Answer 2

clear pictureBox in c# winform Application Simple way to clear pictureBox in c# winform Application

Answer 3

I assume you want to clear the Images drawn via PictureBox.

This you would be achieved via a Bitmap object and using Graphics object. you might be doing something like

Graphics graphic = Graphics.FromImage(pictbox.Image);
graphic.Clear(Color.Red) //Color to fill the background and reset the box

Is this what you were looking out?

EDIT

Since you are using the paint method this would cause it to be redrawn every time, I would suggest you to set a flag at the formlevel indicating whether it should or not paint the Picturebox

private bool _shouldDraw = true;
public bool ShouldDraw
{
    get { return _shouldDraw; }
    set { _shouldDraw = value; }
}

In your paint just use

if(ShouldDraw)
  //do your stuff

When you click the button set this property to false and you should be fine.

Answer 4

I've had a stubborn image too, that wouldn't go away by setting the Image and InitialImage to null. To remove the image from the pictureBox for good, I had to use the code below, by calling Application.DoEvents() repeatedly:

            Application.DoEvents();
            if (_pictureBox.Image != null)
                _pictureBox.Image.Dispose();
            _pictureBox.Image = null;
            Application.DoEvents();
            if (_pictureBox.InitialImage != null)
                _pictureBox.InitialImage.Dispose();
            _pictureBox.InitialImage = null;
            _pictureBox.Update();
            Application.DoEvents();
            _pictureBox.Refresh();

Answer 5

Setting the Image property to null will work just fine. It will clear whatever image is currently displayed in the picture box. Make sure that you've written the code exactly like this:

picBox.Image = null;

Answer 6

I had to add a Refresh() statement after the Image = null to make things work.