问题:

I'm using .NET to draw a diagram, and I want to highlight objects when the user performs a click on them. It is easy when a figure is fully contained in a rectangle:

if (figure.Bounds.Contains(p)) // bounds is a rectangle

But I don't know how to manage it if the figure is a complex GraphicsPath.

I have defined the following GraphicsPath for the figure (the green circle).

I want to highlight the figure when the user click on it. I would like to know if a Point is contained in that GraphicsPath.

Any ideas? Thanks in advance.

回答1:

I don't know a DrawingPath (you mean probably; graphics.DrawPath) but a GraphicsPath has the IsVisible method to check if a point is in the path.

bool isInPath = graphicsObj.IsVisible(point)

回答2:

Using both .IsOutlineVisible and .IsVisible together cover the whole thing, border and within border, for this rectangle example, but as you know GraphicsPath can works for different shapes.

  bool b = gp.IsVisible(point) || gp.IsOutlineVisible(point, pen);

For it in code

 Rectangle r = new Rectangle(new Point(50, 100), new Size(500, 100));
 bool b;
 // say Point p is set.
 // say Pen pen is set.

 using (var gp = new GraphicsPath())
 using (var pen = new Pen(Color.Black, 44)) {
    gp.AddRectangle(r);
    bool b = gp.IsVisible(point) || gp.IsOutlineVisible(point, pen);              
  }