C # generate a pie chart by using GDI

Using system;
Using system. configuration;
Using system. Data;
Using system. LINQ;
Using system. Web;
Using system. Web. Security;
Using system. Web. UI;
Using system. Web. UI. htmlcontrols;
Using system. Web. UI. webcontrols;
Using system. Web. UI. webcontrols. webparts;
Using system. xml. LINQ;
Using system. drawing;
Public partial class _ default: system. Web. UI. Page
{
Private string [,] DATA = new string [6, 2];

Protected void page_load (Object sender, eventargs E)
{
Drawingapic ();
}
Public void drawingapic ()
{
Int I;
// Instantiate a bitmap object
Bitmap objbitmap;
Objbitmap = new Bitmap (400,300 );
Graphics objgraphics;
// Instantiate the graphics class
Objgraphics = graphics. fromimage (objbitmap );

// Fill in the background color
Objgraphics. Clear (color. White );

// Circle
Objgraphics. drawrectangle (pens. Black, 1, 1,500,298 );
Objgraphics. drawstring ("the company's turnover statistics for the first half of the year", new font ("", 16, fontstyle. Bold), brushes. Black, new pointf (60, 5 ));

// Obtain data. Here, we simulate 6 months of company business data. The actual application can read data from the database.
Getdata ();

Pointf monthcolor = new pointf (260, 40 );
Pointf fontinfor = new pointf (285, 36 );
For (I = 0; I <= 5; I ++)
{
// Draw a filled rectangle
Objgraphics. fillrectangle (New solidbrush (getcolor (I), monthcolor. X, monthcolor. Y, 20, 10 );
 
// Draw a rectangular border.
Objgraphics. drawrectangle (pens. Black, monthcolor. X, monthcolor. Y, 20, 10 );
 
// Draw the legend description text-data (I, 0)
Objgraphics. drawstring (data [I, 0], new font ("", 10), brushes. Black, fontinfor );
 
// Move the coordinates and only move the value in the Y direction.
Monthcolor. Y + = 15;
Fontinfor. Y + = 15;
}
// Traverse each item of data from the data source and draw a rectangular chart (that is, the column of the column chart) based on the data size ).
For (I = 0; I <= 5; I ++)
{
// Draw a filled rectangle.
Objgraphics. fillrectangle (New solidbrush (getcolor (I), (I * 25) + 35,270-system. convert. toint32 (data [I, 1]), 15, system. convert. toint32 (data [I, 1]);

// 'Draw a rectangular border line.
Objgraphics. drawrectangle (pens. black, (I * 25) + 35,270-system. convert. toint32 (data [I, 1]), 15, system. convert. toint32 (data [I, 1]);
}

// Draw schematic coordinates
Objgraphics. drawline (new pen (color. Blue, 1), 10, 0, and 10,320 );
Objgraphics. drawline (new pen (color. Blue, 1), 10,270,200,270 );
 
// Add a numerical mark to the coordinate. Note the calculation of coordinates.
For (I = 0; I <= 5; I ++)
{
Objgraphics. drawline (new pen (color. Blue, 1), 10, I * 50 + 20, 20, I * 50 + 20 );
Objgraphics. drawstring (250-I * 50). tostring (), new font ("", 10), brushes. Black, 12, I * 50 + 8 );
}
// Count the total sales
Float scount = 0;
For (I = 0; I <= 5; I ++)
{
Scount + = float. parse (data [I, 1]);
}
 
// Define the sector angle variable
Float SCG = 0;
Float STG = 0;
For (I = 0; I <= 5; I ++)
{
// Calculate the current angle value: current month's sales/total sales * 360, and obtain the current month's angle in the pie chart.
Float num = float. parse (data [I, 1]);
SCG = (Num/scount) * 360;
 
// Draw the filled arc.
Objgraphics. fillpie (New solidbrush (getcolor (I), 220,150,120,120, Stg, SCG );
 
// Draw the arc line.
Objgraphics. drawpie (pens. Black, 220,150,120,120, Stg, SCG );
 
// Add the current arc angle to the total angle.
STG + = SCG;
}
 
// Draw instructions
Objgraphics. drawstring ("Bar Chart", new font ("", 15, fontstyle. Bold), brushes. Blue, 50,272 );
Objgraphics. drawstring ("Pie Chart", new font ("", 15, fontstyle. Bold), brushes. Blue, 250,272 );
 
// Output to the client
Objbitmap. Save (response. outputstream, system. Drawing. imaging. imageformat. GIF );
 
}

Private void getdata ()
{
Data [0, 0] = "January ";
Data [1, 0] = "January February ";
Data [2, 0] = "January March ";
Data [3, 0] = "January April ";
Data [4, 0] = "January May ";
Data [5, 0] = "January June ";
Data [0, 1] = "85 ";
Data [1, 1] = "135 ";
Data [2, 1] = "85 ";
Data [3, 1] = "110 ";
Data [4, 1] = "130 ";
Data [5, 1] = "200 ";
}
// Generate color values for easy display
Private color getcolor (int I)
{
Color newcolor;
I + = 1;
If (I = 1)
{
Newcolor = color. blue;
}
Else if (I = 2)
{
Newcolor = color. forestgreen;
}
Else if (I = 3)
{
Newcolor = color. gainsboro;
}
Else if (I = 4)
{
Newcolor = color. moccasin;
}
Else if (I = 5)
{
Newcolor = color. Indigo;
}
Else if (I = 6)
{
Newcolor = color. burlywood;
}
Else
Newcolor = color. goldenrod;
Return newcolor;
}
}