Drawing multiple lines with DrawLines and DrawLine produces different result - winforms

Question

I am trying to draw multiple lines on a winforms panel using it's graphics object in paint event. I am actually drawing a number of lines joining given points. So, first of all I did this,
private void panel1_Paint(object sender, PaintEventArgs e)
{
e.Graphics.DrawLines(new Pen(new SolidBrush(Color.Crimson), 3), PointFs.ToArray());
float width = 10;
float height = 10;
var circleBrush = new SolidBrush(Color.Crimson);
foreach (var point in PointFs)
{
float rectangleX = point.X - width / 2;
float rectangleY = point.Y - height / 2;
var r = new RectangleF(rectangleX, rectangleY, width, height);
e.Graphics.FillEllipse(circleBrush, r);
}
}
Which produces a result like the image below,
As you can see lines are drawn with having a little bit of extension at sharp turns, which is not expected. So, I changed the drawlines code to,
var pen = new Pen(new SolidBrush(Color.Crimson), 3);
for (int i = 1; i < PointFs.Count; i++)
{
e.Graphics.DrawLine(pen, PointFs[i - 1], PointFs[i]);
}
And now the drawing works fine.
Can anyone tell the difference between the two approaches?

Answer 1

I have just had the same problem (stumbled upon this question during my research), but I have now found the solution.
The problem is caused by the LineJoin property on the Pen used. This DevX page explains the different LineJoin types (see Figure 1 for illustrations). It seems that Miter is the default type, and that causes the "overshoot" when you have sharp angles.
I solved my problem by setting the LineJoin property to Bevel:
var pen = new Pen(new SolidBrush(Color.Crimson), 3);
pen.LineJoin = Drawing2D.LineJoin.Bevel;
Now DrawLines no longer overshoot the points.