First of all, don't use
PictureBox for such purpose. Even though you can, it won't help you at all, will only add some hassles and eat up a bit of extra resources, giving nothing in return. This control in nothing but a shortcut for very simple cases. You need to draw immediately on some control (a custom one derived from
System.Windows.Forms.Control,
Panel or the like). I'll explain how:
How do I clear a panel from old drawing[
^],
draw a rectangle in C#[
^],
Append a picture within picturebox[
^].
See also these past answers:
Drawing Lines between mdi child forms[
^],
capture the drawing on a panel[
^],
What kind of playful method is Paint? (DataGridViewImageCell.Paint(...))[
^],
How to speed up my vb.net application?[
^].
Now when it's clear, you have a choice: you can draw your pixels immediately in
OnPaint (please see below), or you might need to do it on
Bitmap. You can even make both in the same method. You only need to abstract out the instance of
System.Drawing.Graphics, make it a parameter of drawing function. You will take it parameter from event args, in case of
OnPaint, of from bitmap — this way:
http://msdn.microsoft.com/en-us/library/system.drawing.graphics.fromimage.aspx[
^].
Now, the problem could be
performance. If you really need to draw the image pixel-by-pixel using
SetPixel, and there are many pixels,
it will be prohibitively slow, don't do it! In this case, always use bitmap.
The only fast way is using
System.Drawing.Bitmap.LockBits:
http://msdn.microsoft.com/en-us/library/system.drawing.bitmap.lockbits.aspx[
^].
—SA
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