private Point RectStartPoint;
private Image img;
private Image imgClone;
private Pen myPen;
private n = 10; //number of points
你必须初始化这些对象,也许在:
public Form1()
{
InitializeComponent();
myPen = new Pen(Brushes.Red, 2);
//Bitmap to hold the picturebox image
img = new Bitmap(pictureBox1.Width, pictureBox1.Height);
Graphics g;
using (g = Graphics.FromImage(img))
{
g.DrawImage(imageOfPicturebox, 0, 0, pictureBox1.Width, pictureBox1.Height);
}
//image to hold the original picturebox. We need it to clear img to the original
//picturebox image
imgClone = (Bitmap)img.Clone();
//We draw always on img and then we invalidate
pictureBox1.Image = img;
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
RectStartPoint = e.Location;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && e.Location != RectStartPoint)
{
DrawRectangle(e.Location);
}
}
private void DrawRectangle(Point pnt)
{
Graphics g = Graphics.FromImage(img);
int width, height, i, x, y;
g.SmoothingMode = SmoothingMode.AntiAlias;
//Clear img from the rectangle we drawn previously
g.DrawImage(imgClone, 0, 0);
if (pnt.X == RectStartPoint.X || pnt.Y == RectStartPoint.Y)
{
g.DrawLine(myPen, RectStartPoint.X, RectStartPoint.Y, pnt.X, pnt.Y);
}
else
{
g.DrawRectangle(myPen, Math.Min(RectStartPoint.X, pnt.X), Math.Min(RectStartPoint.Y, pnt.Y),
Math.Abs(RectStartPoint.X - pnt.X), Math.Abs(RectStartPoint.Y - pnt.Y));
//width of spaces between points
width = (int)((Math.Abs(RectStartPoint.X - pnt.X))/(n - 1));
//height of spaces between points
height = (int)((Math.Abs(RectStartPoint.Y - pnt.Y))/(n - 1));
//we always want the upper left x, y coordinates as a reference drawing clockwise
x = Math.Min(RectStartPoint.X, pnt.X);
y = Math.Min(RectStartPoint.Y, pnt.Y);
//Drawing the points. change the 3, 6 values for larger ones
for (i = 0; i < n - 1; i++)
{
//Up side
g.FillEllipse(Brushes.Green, new Rectangle(x - 3, Math.Min(RectStartPoint.Y, pnt.Y) - 3, 6, 6));
//Right side
g.FillEllipse(Brushes.Green, new Rectangle(Math.Min(RectStartPoint.X, pnt.X) + Math.Abs(RectStartPoint.X - pnt.X) - 3, y - 3, 6, 6));
//Bottom side
g.FillEllipse(Brushes.Green, new Rectangle(x - 3, Math.Min(RectStartPoint.Y, pnt.Y) + Math.Abs(RectStartPoint.Y - pnt.Y) - 3, 6, 6));
//Left side
g.FillEllipse(Brushes.Green, new Rectangle(Math.Min(RectStartPoint.X, pnt.X) - 3, y - 3, 6, 6));
x += width;
y += height;
}
g.FillEllipse(Brushes.Green, new Rectangle(Math.Min(RectStartPoint.X, pnt.X) + Math.Abs(RectStartPoint.X - pnt.X) - 3,
Math.Min(RectStartPoint.Y, pnt.Y) - 3, 6, 6));
g.FillEllipse(Brushes.Green, new Rectangle(Math.Min(RectStartPoint.X, pnt.X) + Math.Abs(RectStartPoint.X - pnt.X) - 3,
Math.Min(RectStartPoint.Y, pnt.Y) + Math.Abs(RectStartPoint.Y - pnt.Y) - 3, 6, 6));
}
g.Dispose();
//draw img to picturebox
pictureBox1.Invalidate();
}
你的例子有点令人困惑,因为你说你想要10分,但只画4分。但是你是否说过,你想要一个函数,你可以通过矩形的四个边(北,南,东,西)之一和一个数字,它会沿着一个边绘制圆的数量? – Icemanind 2014-09-23 22:56:57
icemanind在我的问题中我提到我用4点上传的图像只是我想要做的一个例子。它可以在每个边缘上4点,或者10或25或100个用户将决定。而对于第二部分你是对的,我想给一个数字让我们说12,它将在北部,南部,东部,西部的每个边缘上在它们之间的相同空间中绘制12个填充点。 – 2014-09-23 23:14:11