c#使用GDI+简单绘图

    // Create the in-memory bitmap where you will draw the image.  
    // This bitmap is 300 pixels wide and 50 pixels high.  
    Bitmap image = new Bitmap(300,50);  
      
    // get the graphics context  
    Graphics g = Graphics.FromImage(image);  
      
    // Draw a solid white rectangle.  
    // Start from point (1,1).  
    // Make it 298 pixels wide and 48 pixels high.  
    g.FillRectangle(Brushes.White,1,298,48);  
      
    // load a font and use it to draw a string  
    Font font = new Font("Impact",20,FontStyle.Regular);  
    g.DrawString("This is a test.",font,Brushes.Blue,10,5);  
      
    // write the image to the output stream.  
    image.Save(Response.OutputStream,System.Drawing.Imaging.ImageFormat.Gif);  
      
    // dispose of the context and the bitmap  
    g.Dispose();  
    image.Dispose();  

    // Create the in-memory bitmap where you will draw the image.  
    // This bitmap is 450 pixels wide and 100 pixels high.  
    Bitmap image = new Bitmap(450,100);  
    Graphics g = Graphics.FromImage(image);  
      
    // Ensure high-quality curves.  
    g.SmoothingMode = SmoothingMode.AntiAlias;  
      
    // Paint the background.  
    g.FillRectangle(Brushes.White,450,100);  
      
    // Add an ellipse.  
    g.FillEllipse(Brushes.PaleGoldenrod,120,13,300,50);  
    g.DrawEllipse(Pens.Green,299,49);  
      
    // Draw some text using a fancy font.  
    Font font = new Font("Harrington",FontStyle.Bold);  
    g.DrawString("Oranges are tasty!",Brushes.DarkOrange,150,20);  
      
    // Add a graphic from a file.  
    System.Drawing.Image orangeImage =  
      System.Drawing.Image.FromFile(Server.MapPath("oranges.gif"));  
    g.DrawImageUnscaled(orangeImage,0);  
      
    // Render the image to the output stream.  
    image.Save(Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);  
      
    // Clean up.  
    g.Dispose();  
    image.Dispose();