CODEWITHSUNDEEP
c#asp.netdrawing
notAnonymousAnymore
notAnonymousAnymore

Reputation: 2687

Draw and fill a simple rectangle

How can I use System.Drawing to do this?

I just want to be able to specify dimensions and background color (in hex) and eventually end up with an Image.

I've looked at similar questions (like this one) but they're more for WinForms - I need it for ASP.Net.

Upvotes: 1

Views: 16102

Answers (3)

Brian Mains
Brian Mains

Reputation: 50728

You can use those approaches, create the image, and save it to the hard disk. Then serve it up to the user. So the extra step for ASP.NET is to save it to the hard disk. Otherwise, everything else can work as is.

Upvotes: 0

Stefan Paul Noack
Stefan Paul Noack

Reputation: 3734

You can't directly use System.Drawing on a ASP.NET web form, because the page is displayed by the browser, which only understands HTML and CSS, your code is executed on the server, though. For displaying a simple rectangle I strongly recommend using CSS.

However, if you really need server-generated graphics, the procedure is as follows:

  • Create a new Bitmap (which is also an Image)
  • Draw whatever you like using the Graphics object. (Hint: Graphics.FromImage())
  • Save the Bitmap into a file on your server (choose appropriate format, e.g. PNG) in a path where it can be acessed via web
  • Refer to the file in your page using the <img> tag.

Upvotes: 1

Josh
Josh

Reputation: 2975

You can do something like this:

<%@ Page Language="C#" ContentType="image/jpeg" %>
<%@ Import Namespace="System.Drawing" %>
<%@ Import Namespace="System.Drawing.Text" %>
<%@ Import Namespace="System.Drawing.Imaging" %>
<%@ Import Namespace="System.Drawing.Drawing2D" %>

<%

Response.Clear();
int height = 100;
int width = 200;
Random r = new Random();
int x = r.Next(75);

Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(bmp);

g.TextRenderingHint = TextRenderingHint.AntiAlias;
g.Clear(Color.Orange);
g.DrawRectangle(Pens.White, 1, 1, width-3, height-3);
g.DrawRectangle(Pens.Gray, 2, 2, width-3, height-3);
g.DrawRectangle(Pens.Black, 0, 0, width, height);
g.DrawString("The Code Project", new Font("Arial", 12, FontStyle.Italic), 
SystemBrushes.WindowText, new PointF(x,50) );

bmp.Save(Response.OutputStream, ImageFormat.Jpeg);
g.Dispose();
bmp.Dispose();
Response.End();

%>

Here's a link to the full article: http://www.codeproject.com/KB/aspnet/aspnet_web_graphics.aspx

Upvotes: 5

Related Questions