c# 可以旋转的 饼形图 实例源码

其中用到了 timer控件

public partial class Frm_Main : Form { public class PyPanel : Panel { public PyPanel() { SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, true); UpdateStyles(); } } public Frm_Main() { InitializeComponent(); } SqlConnection con; SqlCommand cmd; private void Conn() { con = new SqlConnection("server=WRET-MOSY688YVW\\MRGLL;UID=sa;Pwd=hbyt2008!@#;database=db_TomeOne"); con.Open(); } Bitmap bt; Bitmap bt1; int flag = 0; PyPanel panel1 = new PyPanel(); private void ShowPic(string SexCode, float f)// ShowPic方法绘制饼图 { this.Controls.Add(panel1);//将Panel控件添加到窗体中 panel1.Width = 230;//设置Panel控件的宽度 panel1.Height = 230;//设置Panel控件的高度 bt = new Bitmap(panel1.Width, panel1.Height);//创建画布 Graphics g = Graphics.FromImage(bt);//创建Graphics对象 Pen p = new Pen(new SolidBrush(Color.Blue));//创建画笔 Point p1 = new Point(0, 0);//创建一个Point对象 Size s = new Size(this.panel1.Width, this.panel1.Height);//创建Size对象 Rectangle trct = new Rectangle(p1, s);//创建Rectangle对象 g.FillEllipse(new SolidBrush(Color.Red), trct);//绘制椭圆 g.FillPie(new SolidBrush(Color.Blue), trct, flag, f * 360);//绘制扇形 bt1 = new Bitmap(panel2.Width, panel2.Height);//创建画布 Graphics ginfo = Graphics.FromImage(bt1);//创建Graphics对象 Font font = new Font("宋体", 10, FontStyle.Regular);//设置字体 ginfo.DrawString(SexCode " " f.ToString().Substring(0, 4), font, new SolidBrush(Color.Blue), 0, 5); ginfo.DrawString("女" " " (1.0 - Convert.ToDouble(f.ToString().Substring(0, 4))).ToString().Substring(0, 4), font, new SolidBrush(Color.Red), 0, 25);//绘制性别及比率 panel1.BackgroundImage = bt;//显示饼图 panel2.BackgroundImage = bt1;//显示性别及比率 } private void button1_Click(object sender, EventArgs e)//单击“显示”按钮显示饼图 { Conn();//连接数据库 //using (cmd = new SqlCommand("SELECT sex,COUNT(sex) num FROM tb_sex group by sex", con)) using (cmd = new SqlCommand("SELECT sex,COUNT(sex) num FROM tb_sex group by sex", con)) { SqlDataReader dr = cmd.ExecuteReader();//创建SqlDataReader对象 string[] str = new string[2]; int i = 0; while (dr.Read())//读取记录 { str[i] = dr[0].ToString() "," dr[1].ToString();//获取数据库中存储的性别及比例 i ; } float N = Convert.ToInt16(str[0].Substring(2)) Convert.ToInt16(str[1].Substring(2));//男女性别比例之和 float f = Convert.ToInt16(str[0].Substring(2)) / N;//男性的比例 flag = 180;//开始绘制的起始角度 ShowPic(str[0].Substring(0, 1), f);//调用ShowPic方法绘制饼图 } con.Close(); } private void timer1_Tick(object sender, EventArgs e)//当单击“旋转”按钮时开始旋转饼图 { flag = 1;//每次转动一度 Conn();//连接数据库 using (cmd = new SqlCommand("SELECT sex,COUNT(sex) num FROM tb_sex group by sex", con)) { SqlDataReader dr = cmd.ExecuteReader();//创建SqlDataReader对象 string[] str = new string[2];//声明数组存储性别及比例 int i = 0; while (dr.Read()) { str[i] = dr[0].ToString() "," dr[1].ToString();//获取数据库中存储的性别及比例 i ; } float N = Convert.ToInt16(str[0].Substring(2)) Convert.ToInt16(str[1].Substring(2)); //男女性别比例之和 float f = Convert.ToInt16(str[0].Substring(2)) / N;//男性的比例 ShowPic(str[0].Substring(0, 1), f);//调用ShowPic方法绘制饼图 } con.Close();//关闭连接 } private void button2_Click(object sender, EventArgs e)//“旋转”按钮 { if (button2.Text == "旋转")//如果按钮显示“旋转”文本 { timer1.Start();//开始Timer控件 button2.Text = "停止";//将按钮的文本设为“停止” } else//如果按钮的文本为“停止” { timer1.Stop();//停止Timer控件 button2.Text = "旋转";//将按钮的文本设为“旋转” } } }