Draw a Polygon using Mouse Points in C#
I need to be able to draw a polygon using mouse click locations. Here is my current code:
//the drawshape varible is called when a button is pressed to select use of this tool
if (DrawShape == 4)
{
Point[] pp = new Point[3];
pp[0] = new Point(e.Location.X, e.Location.Y);
pp[1] = new Point(e.Location.X, e.Location.Y);
pp[2] = new Point(e.Location.X, e.Location.Y);
Graphics G = this.CreateGraphics();
开发者_StackOverflow社区 G.DrawPolygon(Pens.Black, pp);
}
Thanks
Ok here is some sample code:
private List<Point> polygonPoints = new List<Point>();
private void TestForm_MouseClick(object sender, MouseEventArgs e)
{
switch(e.Button)
{
case MouseButtons.Left:
//draw line
polygonPoints.Add(new Point(e.X, e.Y));
if (polygonPoints.Count > 1)
{
//draw line
this.DrawLine(polygonPoints[polygonPoints.Count - 2], polygonPoints[polygonPoints.Count - 1]);
}
break;
case MouseButtons.Right:
//finish polygon
if (polygonPoints.Count > 2)
{
//draw last line
this.DrawLine(polygonPoints[polygonPoints.Count - 1], polygonPoints[0]);
polygonPoints.Clear();
}
break;
}
}
private void DrawLine(Point p1, Point p2)
{
Graphics G = this.CreateGraphics();
G.DrawLine(Pens.Black, p1, p2);
}
First, add this code:
List<Point> points = new List<Point>();
On the object you are drawing on, capture the OnClick event. One of the arguments should have the X and Y coordinates of the click. Add them to the points array:
points.Add(new Point(xPos, yPos));
And then finally, where you're drawing the lines, use this code:
if (DrawShape == 4)
{
Graphics G = this.CreateGraphics();
G.DrawPolygon(Pens.Black, points.ToArray());
}
EDIT:
Ok, so the above code isn't exactly correct. First of all, its most likely a Click event instead of a OnClick event. Second, To get the mouse position, you need two variables declared up with the points array,
int x = 0, y = 0;
Then have a mouse move event:
private void MouseMove(object sender, MouseEventArgs e)
{
x = e.X;
y = e.Y;
}
Then, in your Click event:
private void Click(object sender, EventArgs e)
{
points.Add(new Point(x, y));
}
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