绘制柱形图（对排序数据进行分析）

 

private SqlConnection conn = new SqlConnection("server=.;uid=sa;pwd=sa;database= MyProject");

 

                    /// <summary>        /// 升序        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button2_Click(object sender, EventArgs e)        {            string str = "asc";            showPic(str);        }

        /// <summary>        /// 降序        /// </summary>        /// <param name="sender"></param>        /// <param name="e"></param>        private void button1_Click(object sender, EventArgs e)        {            string str = "desc";            this.showPic(str);        }

 

 

private void showPic(string str)        {                conn.Open();                string sql = "select * from GetEmplores order by EmployeePrice " + str + "";                SqlCommand cmd = new SqlCommand(sql,conn);                 SqlDataReader dr = cmd.ExecuteReader();                                Bitmap bit = new Bitmap(this.panel1.Width,this.panel1.Height);                Graphics g = Graphics.FromImage(bit);

                try                {                    g.Clear(Color.White);

                    //绘制水平线条                    for (int i = 0; i < 5; i++)                    {                        g.DrawLine(new Pen(new SolidBrush(Color.Red), 2.0f), 50, this.panel1.Height - 20 - i * 20, this.panel1.Width - 40, this.panel1.Height - 20 - i * 20);                        g.DrawString(Convert.ToString(i * 100), new Font("Times New Roman", 10, FontStyle.Regular), new SolidBrush(Color.Black), 20, this.panel1.Height - 27 - i * 20);                    }

                    //绘制垂直线条                    for (int j = 0; j < 4; j++)                    {                        g.DrawLine(new Pen(new SolidBrush(Color.Red), 1.0f), 50 + 40 * j, this.panel1.Height - 20, 50 + 40 * j, 50);

                        if (dr.Read())                        {                            int x, y, w, h;

                            //绘制商品名称                            g.DrawString(dr[0].ToString(), new Font("宋体", 8, FontStyle.Regular), new SolidBrush(Color.Black), 76 + 40 * j, this.panel1.Height - 16);                            x = 78 + 40 * j;                            y = this.panel1.Height - 20 - Convert.ToInt32((Convert.ToDouble(Convert.ToDouble(dr[1].ToString()) * 20 / 100)));

                            w = 24;                     //宽度                            h = Convert.ToInt32(Convert.ToDouble(dr[1].ToString())*20/100);      //高度                            g.FillRectangle(new SolidBrush(Color.FromArgb(56, 129, 78)), x, y, w, h);                //开始绘制柱形矩形图                        }                    }

                    if (str == "desc")                    {                        //绘制提示文字，提示商品按降序排列                        g.DrawString("热卖前三名", new Font("宋体", 9), new SolidBrush(Color.Red), this.panel1.Width / 2 - 26, 20);                    }                    else if (str == "asc")                    {                        //绘制提示文字，提示商品按升序排列                        g.DrawString("热卖后三名", new Font("宋体", 9), new SolidBrush(Color.Red), this.panel1.Width / 2 - 26, 20);                    }                    this.panel1.BackgroundImage = bit;                }                catch (Exception e)                {                    MessageBox.Show(e.Message);                }                finally                {                    dr.Close();                    conn.Close();                }      

            }