Question

如何用C#画出一个椭圆

Answer 1

需要界面绘图，建议使用WPF，而不是Winform

<Canvas>
<Path Stroke="Red" StrokeThickness="5">
<Path.Data>
<EllipseGeometry Center="100,100" RadiusX="50" RadiusY="30"></EllipseGeometry>
</Path.Data>
</Path>
</Canvas>

以上代码即可在界面上滑出一个X轴弧度为50，Y轴弧度为30的横椭圆

Answer 2

private void Form1_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
Pen p = new Pen(Color.Blue, 2);
g.DrawEllipse(p, 10, 10, 100, 100);
}