Re: drawing circles. - C# Discussion Boards

_AnsHUMAN_ 28-Jun-09 20:17

28-Jun-09 20:17

I don't hardcode the values. I get the center of the form and then try to draw the concentric circles

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

dan!sh 28-Jun-09 20:29

28-Jun-09 20:29

So where is the problem then? Can you show some code and rephrase the problem?

_AnsHUMAN_ 28-Jun-09 20:52

28-Jun-09 20:52

Of course! Based on the size of the form I have to draw concentric circles ( A user can resize the form). So the center of the circles should remain at the center of the form(assuming square shaped form) always. Also the circles should shrink/grow as the user resizes the form. I hope it's clearer now.
In essence I have to create circles dynamically so that the center for two or more circles remain as the center of the form and the radius for each can be calculated in terms of a ratio.

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

dan!sh 28-Jun-09 20:58

28-Jun-09 20:58

The code I had posted does the same. What did you tried? Some code would be of help.

_AnsHUMAN_ 28-Jun-09 21:23

28-Jun-09 21:23

Your code only draws one circle at the center of the dialog. What if I want to draw two circles of different radius at the same center.

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

dan!sh 28-Jun-09 21:53

28-Jun-09 21:53

Use the method two times. Was it this tough?

_AnsHUMAN_ 28-Jun-09 22:22

28-Jun-09 22:22

You didn't read the documentation of DrawEllipse probably.
DrawEllipse - Draws an ellipse defined by a bounding rectangle specified by a pair of coordinates, a height, and a width. So we need to draw the bounding rectangle at the same center coordinates. Right?
When I use your code it draws an ellipse starting at the coordinates(left top corner) you provide and with the width and height, and so the circles are not concentric.

Anyways I have resolved the problem now.
Thanks for your time and effort in helping me.

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

dan!sh 28-Jun-09 22:46

28-Jun-09 22:46

Somehow, these look concentric to me.

gx.Clear(this.BackColor);
     gx = this.CreateGraphics();
     gx.DrawEllipse(Pens.Red, (this.Width / 2 - 25), (this.Height / 2 - 25), 50, 50);
     gx.DrawEllipse(Pens.Red, (this.Width / 2 - 50), (this.Height / 2 - 50), 100, 100);
     gx.DrawEllipse(Pens.Red, (this.Width / 2 - 75), (this.Height / 2 - 75), 150, 150);
     gx.DrawEllipse(Pens.Red, (this.Width / 2 - 100), (this.Height / 2 - 100), 200, 200);

_AnsHUMAN_ 28-Jun-09 23:12

28-Jun-09 23:12

d@nish wrote:
gx.DrawEllipse(Pens.Red, (this.Width / 2 - 25

aren't you hardcoding the values for the rectangle. you are fixing the centers by subtracting some values based on the radius. isn't it? your circles won't get drawn with the same center when you increase or decrease forms size.

You need to google first, if you have "It's urgent please" mentioned in your question.
Wink | ;-)

_AnShUmAn_

dan!sh 28-Jun-09 23:36

28-Jun-09 23:36

Only thing I have fixed is the radius of the circles, and that is because this is just some sample code.

You need to handle the Resize event for the form as well and only then, no matter how you resize the form, the circles will be drawn with form's center as their center.