[SOLVED] Why does my SetPixel function not work in my PictureBox?

Why does my SetPixel function not work in my PictureBox?

I have a problem with SetPixel Function In VB.NET

I am trying to set a color of a specified place in the picturebox.

I want to make the point(X : 45,Y : 55) in the color red.

I searched for a function to do that. And I found SetPixel.

I wrote my code in a button.

This is my code :

Private Sub btn_Set_Click(sender As Object, e As EventArgs) Handles btn_Set.Click
  Dim pic1 As New Bitmap(PictureBox1.Image)
  pic1.SetPixel(45, 55, Color.Red)
End Sub

But it doesn't work. When I click on the button. nothing happens.

Why it doesn't work?

Note: there is no image in the picturebox. I just set a backColor to the picturebox.

Solution

You can print pixel with Graphics

You need to import

Imports System.Drawing.Graphics

I added the drawline as the pixel is not really visible

Private Sub btn_Set_Click(sender As Object, e As EventArgs) Handles btn_Set.Click
    Dim pic1 As New Bitmap(200, 100)

    Dim gr As Graphics
    gr = Graphics.FromImage(pic1)
    Dim p As Pen = New Pen(Color.Red, 2)
    'printline
    gr.DrawLine(p, 30, 30, 45, 55)
    'Print pixel
    gr.FillRectangle(Brushes.Blue, 55, 55, 1, 1)
    PictureBox1.Image = pic1
    PictureBox1.Update()
    PictureBox1.Refresh()
End Sub