graphics - C# drawing issue -

i have general question drawing in c#. in class test have method draw:

public void draw(graphics g)     {         g.drawline(pens.black, x1, y1, x2, y2);     } 

and want draw in main form in picturebox called picturebox1

but how can draw it?

normally can draw in picturebox this:

private void draw() {    graphics g = picturebox1.creategraphics();    g.drawline(pens.black, x1, y1, x2, y2); } 

i know silly question, beginner , want basics ;)

best wishes :)

edit:

sorry, don't understand postings @ all, can explain me again

edit 2:

thanks answers. don't know how works.

there class test , in class there draw method:

private void draw() {    graphics g = picturebox1.creategraphics();    g.drawline(pens.black, x1, y1, x2, y2); } 

now want draw methode in picturebox in mainclass formmain

how can draw test.draw() in picturbox in other class?

i hope clear , sorry inexperience best wishes

the picturebox control overwrite whatever on each time paint event gets fired (which pretty time). need wire event:

this.picturebox1.paint += new painteventhandler(picturebox1_paint); 

then in event drawing:

void picturebox1_paint(object sender, painteventargs e) {      // assuming constructor takes coordinates parameters      var t = new test(0, 0, 100, 100);      t.draw(e.graphics); }