C# 实现常用图表源代码：柱状图、饼图与折线图绘制详解

///////////////////////////////////////////////////////柱状图

private void CreateImage()
{
int height = 500, width = 700;
Bitmap image = new Bitmap(width, height);
//创建Graphics类对象
Graphics g = Graphics.FromImage(image);

try
{
//清空图片背景色
g.Clear(Color.White);

Font font = new Font("Arial", 10, FontStyle.Regular);
Font font1 = new Font("宋体", 20, FontStyle.Bold);

LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), 
Color.Blue, Color.BlueViolet, 1.2f, true);
g.FillRectangle(Brushes.WhiteSmoke, 0, 0, width, height);
// Brush brush1 = new SolidBrush(Color.Blue);

g.DrawString(this.ddlTaget.SelectedItem.Text + " " + this.ddlYear.SelectedItem.Text + 
" 成绩统计柱状图", font1, brush, new PointF(70, 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);

//绘制线条
//绘制横向线条
int x = 100;
for (int i = 0; i < 14; i++)
{
g.DrawLine(mypen, x, 80, x, 340);
x = x + 40;
}
Pen mypen1 = new Pen(Color.Blue, 2);
x = 60;
g.DrawLine(mypen1, x, 80, x, 340);

//绘制纵向线条
int y = 106;
for (int i = 0; i < 9; i++)
{
g.DrawLine(mypen, 60, y, 620, y);
y = y + 26;
}
g.DrawLine(mypen1, 60, y, 620, y);

//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 = 78;
for (int i = 0; i < 7; i++)
{
g.DrawString(n[i].ToString(), font, Brushes.Blue, x, 348); //设置文字内容及输出位置
x = x + 78;
}