Bar Graph for Sales
Bar Graph for Sales
Bar Graph for Sales
Start a new project. There are no controls in this project.
Add this code, using the lightening bolt to select the paint event.:
// Programmer: Janet Joy
// Display a bar graph for sales.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Sales
{
public partial class Form1 : Form
{
int[] sales = { 25, 40, 50, 30, 20, 70, 80, 85, 90, 10, 20,45 };
String[] months = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jly", "Aug", "Spt", "Oct", "Nov", "Dec" };
// Colors will repeat if necesary
Color[] colors = { Color.DarkRed, Color.DarkOliveGreen, Color.DarkCyan, Color.CadetBlue };
public Form1()
{
InitializeComponent();
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
// Get the graphics of the form.
Graphics g = this.CreateGraphics();
// Create a brush
SolidBrush myBrush = new SolidBrush(Color.Black);
// Set the top to 0 for the first row.
int top = 0;
// We will create a graph that is 300 pixels wide.
// We will make each bar in the graph proportional with the max value at 300.
int max = sales.Max();
float ratio = 300.0F / max;
for(int i=0;i<sales.Length; i++)
{
// Set the color to black for the text.
myBrush.Color = Color.Black;
// Draw the name of the month.
g.DrawString(months[i], this.Font, myBrush, 0.0F, top);
// Set the color to the next color in array or back to 0.
// The mod operator will give values within the rrray: 0,1,2,3,0,1,2...
int clr = i % colors.Length;
myBrush.Color = colors[clr];
// Calculate the width of the box.
int width = (int)(sales[i] * ratio);
Rectangle myRect = new Rectangle(30, top, width, 20);
// Draw the bar graph.
g.FillRectangle(myBrush, myRect);
// Switch back to Black to write on top of the bar.
myBrush.Color = Color.Black;
// Draw the amount of sales.
g.DrawString(sales[i].ToString(), this.Font, myBrush, 40.0F, top);
// Increment top for the next row.
top += 20;
}
}
}
}
To Do: Experiment!
Try reading the sales from a file (you will need lists instead of arrays).
Add a legend. Make vertical bars instead of a horizontal bars.