Asp.Net实例：C# 绘制统计图（二） ——折线统计图的绘制-阿里云开发者社区

二 . 折线统计图的绘制

效果 :

折线图的完整代码 :

折线图的完整代码
private void CreateImage()
{
int height = 480, width = 700;
Bitmap image = new Bitmap(width, height);
Graphics g = Graphics.FromImage(image);

try
{
// 清空图片背景色
g.Clear(Color.White);

Font font = new System.Drawing.Font("Arial", 9, FontStyle.Regular);
Font font1 = new System.Drawing.Font(" 宋体 ", 20, FontStyle.Regular);
Font font2 = new System.Drawing.Font("Arial", 8, FontStyle.Regular);
LinearGradientBrush brush = new LinearGradientBrush(
new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.Blue, 1.2f, true);
g.FillRectangle(Brushes.AliceBlue, 0, 0, width, height);
Brush brush1 = new SolidBrush(Color.Blue);
Brush brush2 = new SolidBrush(Color.SaddleBrown);

g.DrawString(this.ddlTaget.SelectedItem.Text + " " + this.ddlYear.SelectedItem.Text +
" 成绩统计折线图 ", font1, brush1, new PointF(85, 30));
// 画图片的边框线
g.DrawRectangle(new Pen(Color.Blue), 0, 0, image.Width - 1, image.Height - 1);

Pen mypen = new Pen(brush, 1);
Pen mypen2 = new Pen(Color.Red, 2);
// 绘制线条
// 绘制纵向线条
int x = 60;
for (int i = 0; i < 8; i++)
{
g.DrawLine(mypen, x, 80, x, 340);
x = x + 80;
}
Pen mypen1 = new Pen(Color.Blue, 3);
x = 60;
g.DrawLine(mypen1, x, 82, x, 340);

// 绘制横向线条
int y = 106;
for (int i = 0; i < 10; i++)
{
g.DrawLine(mypen, 60, y, 620, y);
y = y + 26;
}
// y = 106;
g.DrawLine(mypen1, 60, y - 26, 620, y - 26);

//x 轴
String[] n = { " 第一期 ", " 第二期 ", " 第三期 ", " 第四期 ", " 上半年 ", " 下半年 ", " 全年统计 " };
x = 45;
for (int i = 0; i < 7; i++)
{
g.DrawString(n[i].ToString(), font, Brushes.Red, x, 348); // 设置文字内容及输出位置
x = x + 77;
}

//y 轴
String[] m = { "220 人 ", " 200 人 ", " 175 人 ", "150 人 ", " 125 人 ", " 100 人 ", " 75 人 ", " 50 人 ",
" 25 人 "};
y = 100;
for (int i = 0; i < 9; i++)
{
g.DrawString(m[i].ToString(), font, Brushes.Red, 10, y); // 设置文字内容及输出位置
y = y + 26;
}

int[] Count1 = new int[7];
int[] Count2 = new int[7];

SqlConnection Con = new SqlConnection("Server=(Local);Database=committeeTraining;Uid=sa;Pwd=eesoft");
Con.Open();
string cmdtxt2 = "SELECT * FROM ##Count where Company='" + this.ddlTaget.SelectedItem.Text.Trim() + "'";
SqlDataAdapter da = new SqlDataAdapter(cmdtxt2, Con);
DataSet ds = new DataSet();
da.Fill(ds);

// 报名人数
Count1[0] = Convert.ToInt32(ds.Tables[0].Rows[0]["count1"].ToString());
Count1[1] = Convert.ToInt32(ds.Tables[0].Rows[0]["count3"].ToString());
Count1[2] = Convert.ToInt32(ds.Tables[0].Rows[0]["count5"].ToString());
Count1[3] = Convert.ToInt32(ds.Tables[0].Rows[0]["count7"].ToString());

Count1[6] = Convert.ToInt32(ds.Tables[0].Rows[0]["count9"].ToString()); // 全年

Count1[4] = Count1[0] + Count1[1];
Count1[5] = Count1[2] + Count1[3];

Count2[0] = Convert.ToInt32(ds.Tables[0].Rows[0]["count2"].ToString());
Count2[1] = Convert.ToInt32(ds.Tables[0].Rows[0]["count4"].ToString());
Count2[2] = Convert.ToInt32(ds.Tables[0].Rows[0]["count6"].ToString());
Count2[3] = Convert.ToInt32(ds.Tables[0].Rows[0]["count8"].ToString());

Count2[6] = Convert.ToInt32(ds.Tables[0].Rows[0]["count10"].ToString()); // 全年

Count2[4] = Count2[0] + Count2[1];
Count2[5] = Count2[2] + Count2[3];

// 显示折线效果
Font font3 = new System.Drawing.Font("Arial", 10, FontStyle.Bold);
SolidBrush mybrush = new SolidBrush(Color.Red);
Point[] points1 = new Point[7];
points1[0].X = 60; points1[0].Y = 340 - Count1[0]; // 从 106 纵坐标开始 , 到 (0, 0) 坐标时
points1[1].X = 140; points1[1].Y = 340 - Count1[1];
points1[2].X = 220; points1[2].Y = 340 - Count1[2];
points1[3].X = 300; points1[3].Y = 340 - Count1[3];

points1[4].X = 380; points1[4].Y = 340 - Count1[4];
points1[5].X = 460; points1[5].Y = 340 - Count1[5];

points1[6].X = 540; points1[6].Y = 340 - Count1[6];
g.DrawLines(mypen2, points1); // 绘制折线

// 绘制数字
g.DrawString(Count1[0].ToString(), font3, Brushes.Red, 58, points1[0].Y - 20);
g.DrawString(Count1[1].ToString(), font3, Brushes.Red, 138, points1[1].Y - 20);
g.DrawString(Count1[2].ToString(), font3, Brushes.Red, 218, points1[2].Y - 20);
g.DrawString(Count1[3].ToString(), font3, Brushes.Red, 298, points1[3].Y - 20);

g.DrawString(Count1[4].ToString(), font3, Brushes.Red, 378, points1[4].Y - 20);
g.DrawString(Count1[5].ToString(), font3, Brushes.Red, 458, points1[5].Y - 20);

g.DrawString(Count1[6].ToString(), font3, Brushes.Red, 538, points1[6].Y - 20);

Pen mypen3 = new Pen(Color.Green, 2);
Point[] points2 = new Point[7];
points2[0].X = 60; points2[0].Y = 340 - Count2[0];
points2[1].X = 140; points2[1].Y = 340 - Count2[1];
points2[2].X = 220; points2[2].Y = 340 - Count2[2];
points2[3].X = 300; points2[3].Y = 340 - Count2[3];

points2[4].X = 380; points2[4].Y = 340 - Count2[4];
points2[5].X = 460; points2[5].Y = 340 - Count2[5];

points2[6].X = 540; points2[6].Y = 340 - Count2[6];
g.DrawLines(mypen3, points2); // 绘制折线

// 绘制通过人数
g.DrawString(Count2[0].ToString(), font3, Brushes.Green, 61, points2[0].Y - 15);
g.DrawString(Count2[1].ToString(), font3, Brushes.Green, 131, points2[1].Y - 15);
g.DrawString(Count2[2].ToString(), font3, Brushes.Green, 221, points2[2].Y - 15);
g.DrawString(Count2[3].ToString(), font3, Brushes.Green, 301, points2[3].Y - 15);

g.DrawString(Count2[4].ToString(), font3, Brushes.Green, 381, points2[4].Y - 15);
g.DrawString(Count2[5].ToString(), font3, Brushes.Green, 461, points2[5].Y - 15);

g.DrawString(Count2[6].ToString(), font3, Brushes.Green, 541, points2[6].Y - 15);

// 绘制标识
g.DrawRectangle(new Pen(Brushes.Red), 180, 390, 250, 50); // 绘制范围框
g.FillRectangle(Brushes.Red, 270, 402, 20, 10); // 绘制小矩形
g.DrawString(" 报名人数 ", font2, Brushes.Red, 292, 400);

g.FillRectangle(Brushes.Green, 270, 422, 20, 10);
g.DrawString(" 通过人数 ", font2, Brushes.Green, 292, 420);

System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType = "image/Jpeg";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}