Draw a line chart/column chart/bar/pie chart with code

Pie chart | Line Chart | Column chart

This article will introduce you to the. NET how to use code drawing tables, just as you would with a chart generated in MS Excel. You can also sketch a DataGrid-like table.
In NET, Microsoft has provided us with the drawing Class (System.Drawing.Imaging), in this class the basic function of drawing. For example: Straight line, line, rectangle, polygon, oval, fan, curve and so on, so the general graphics can be directly drawn through the code. Next, we'll introduce some drawing functions:
Bitmap bmap=new Bitmap (500,500)//define image size;
Bmap.save (Stream,imagecodecinfo)//Saves the image to the specified output stream;
Graphics GPH//define or create GDI drawings for image;
PointF cPt//definition of x,y coordinates in two-dimensional plane;
DrawString (STRING,FONT,BRUSH,PONITF)///To draw the specified string with the specified Brush and Font pairs, as in the specified rectangle or point;
DrawLine (Pen,ponit,ponit)//(pen) to draw a straight line between two points;
DrawPolygon (pen,ponit[])///with the specified pen (pen) to draw the specified polygon, such as triangles, quadrilateral and so on;
FillPolygon (brush,ponit[])//fill the specified polygon with the specified brush (Brush);
DrawEllipse (Pen,x,y,width,height)//Draw a border-defined ellipse with the specified pen;
FillEllipse (brush,x,y,width,height)//Fill a border-defined ellipse with the specified brush;
DrawRectangle (Pen,x,y,width,height)//Draw a rectangle with specified coordinates, width, and height with the pen you specify;
Drawpie (Pen,x,y,width,height,startangle,sweepangle)//-Draws a sector of a specified coordinate point, width, height, and two rays with the specified pen;
OK, so much for the introduction, the parameters are abbreviated. I believe that in the actual use of the process, we will have a more profound experience. Finally, take a simple example to see how to use these drawing functions (line charts).
The code to draw the above line chart is as follows:
Data initialization
String[] month=new string[12]{"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
Float[] D=new float[12]{20.5f,60,10.8f,15.6f,30,70.9f,50.3f,30.7f,70,50.4f,30.8f,20};
Paint initialization
Bitmap bmap=new Bitmap (500,500);
Graphics gph=graphics.fromimage (BMAP);
Gph. Clear (Color.White);

PointF cpt=new PointF (40,420);//Center Point
Pointf[] xpt=new pointf[3]{new PointF (CPT.Y+15,CPT.Y), New PointF (cpt.y,cpt.y-8), New PointF (cpt.y,cpt.y+8)};//x Axis triangle
Pointf[] ypt=new pointf[3]{new PointF (cpt.x,cpt.x-15), New PointF (Cpt.x-8,cpt.x), New PointF (cpt.x+8,cpt.x)};//y Axis triangle
Gph. DrawString ("A product monthly production chart for a Factory", New Font ("XXFarEastFont-Arial"), Brushes.black, New PointF (cpt.x+60, cpt.x));//Chart title
Draw X Axis
Gph. DrawLine (Pens.black, Cpt.x,cpt.y, CPT.Y,CPT.Y);
Gph. DrawPolygon (PENS.BLACK,XPT);
Gph. FillPolygon (New SolidBrush (Color.Black), XPT);
Gph. DrawString ("Month", New Font ("XXFarEastFont-Arial,", Brushes.black, New PointF (cpt.y+10, cpt.y+10));
Draw Y Axis
Gph. DrawLine (Pens.black, cpt.x,cpt.y,cpt.x,cpt.x);
Gph. DrawPolygon (Pens.black,ypt);
Gph. FillPolygon (New SolidBrush (Color.Black), ypt);
Gph. DrawString ("unit (million)", New Font ("XXFarEastFont-Arial",), Brushes.black, new PointF (0, 7));
for (int i=1;i<=12;i++)
{
Draw Y-axis scale
if (i<11)
{
Gph. DrawString ((i*10). ToString (), New Font ("Arial", one), Brushes.black, New PointF (cpt.x-30, cpt.y-i*30-6));
Gph. DrawLine (Pens.black, cpt.x-3,cpt.y-i*30, cpt.x,cpt.y-i*30);
}
Draw X Axis Item
Gph. DrawString (Month[i-1]. Substring (0,1), new Font ("Arial", one), Brushes.black, New PointF (cpt.x+i*30-5, cpt.y+5));
Gph. DrawString (Month[i-1]. Substring (1,1), New Font ("Arial", one), Brushes.black, New PointF (cpt.x+i*30-5, cpt.y+20));
if (month[i-1). LENGTH&GT;2) gph. DrawString (Month[i-1]. Substring (2,1), New Font ("Arial", one), Brushes.black, New PointF (cpt.x+i*30-5, cpt.y+35));
Draw a Point
Gph. DrawEllipse (pens.black,cpt.x+i*30-1.5f,cpt.y-d[i-1]*3-1.5f,3,3);
Gph. FillEllipse (New SolidBrush (Color.Black), cpt.x+i*30-1.5f,cpt.y-d[i-1]*3-1.5f,3,3);
Draw a value
Gph. DrawString (D[i-1]. ToString (), New Font ("XXFarEastFont-Arial", one), Brushes.black, New PointF (cpt.x+i*30,cpt.y-d[i-1]*3));
Draw a polyline
if (i>1) gph. DrawLine (pens.red,cpt.x+ (i-1) *30,cpt.y-d[i-2]*3,cpt.x+i*30,cpt.y-d[i-1]*3);
}
Save output picture
Bmap.save (Response.outputstream, imageformat.gif);