I'm working with images like: https://i.stack.imgur.com/zmQr0.jpg
I've managed to find a vertical line between pages on scanned image. But sometimes there are some errors and I need to make an option for user to change this line position and angle. I think this would be nice within a PictureBox.
I need somehow to draw a line between two movable points on a picturebox with current image. When I move a point, position of line and it's angle have to be changed properly.
Here is a sample code you can use for your need. It basically uses 4 events :
- Paint
- MouseDown
- MouseMove
- MouseUp
You can copy-paste this code to a form called Form1, with a picture box called pictureBox1
int handleRadius = 3;
int mPointMoveInProgress = 0;
Point mPoint1, mPoint2;
public Form1()
{
InitializeComponent();
mPoint1 = new Point(50, 50); // Set correct default values
mPoint1 = new Point(50, 300); // Set correct default values
}
private void pictureBox1_Paint(object sender, PaintEventArgs e)
{
// Draw line
e.Graphics.DrawLine(new Pen(Color.Black, 2), mPoint1, mPoint2);
Rectangle rectangle;
// Draw first handle
rectangle = new Rectangle(mPoint1.X - handleRadius, mPoint1.Y - handleRadius, handleRadius * 2, handleRadius * 2);
e.Graphics.FillRectangle(Brushes.White, rectangle);
e.Graphics.DrawRectangle(Pens.Black, rectangle);
// Draw second handle
rectangle = new Rectangle(mPoint2.X - handleRadius, mPoint2.Y - handleRadius, handleRadius * 2, handleRadius * 2);
e.Graphics.FillRectangle(Brushes.White, rectangle);
e.Graphics.DrawRectangle(Pens.Black, rectangle);
}
private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
// Determine if a point is under the cursor. If so, declare that a move is in progress
if (Math.Abs(e.X - mPoint1.X) < handleRadius && Math.Abs(e.Y - mPoint1.Y) < handleRadius) mPointMoveInProgress = 1;
else if (Math.Abs(e.X - mPoint2.X) < handleRadius && Math.Abs(e.Y - mPoint2.Y) < handleRadius) mPointMoveInProgress = 2;
else mPointMoveInProgress = 0;
}
private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
if (mPointMoveInProgress == 1) // If moving first point
{
mPoint1.X = e.X ;
mPoint1.Y = e.Y ;
Refresh();
}
else if (mPointMoveInProgress == 2) // If moving second point
{
mPoint2.X = e.X ;
mPoint2.Y = e.Y ;
Refresh();
}
else // If moving in the PictureBox: change cursor to hand if above a handle
{
if (Math.Abs(e.X - mPoint1.X) < handleRadius && Math.Abs(e.Y - mPoint1.Y) < handleRadius) Cursor.Current = Cursors.Hand;
else if (Math.Abs(e.X - mPoint2.X) < handleRadius && Math.Abs(e.Y - mPoint2.Y) < handleRadius) Cursor.Current = Cursors.Hand;
else Cursor.Current = Cursors.Default;
}
}
private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
// Declare that no move is in progress
mPointMoveInProgress = 0;
}
use Graphics class.
while there are new events about drawing (in mouse move handler or where it is needed):
// we don't need to change imageSource
Image imgSourceCopy = imageSource.Clone as Image;
Graphics g = Graphics.FromImage(imgSourceCopy);
g.DrawLine(point1, point2);
pictureBox.Image = imgSourceCopy;
imgSourceCopy is used only for drawing line. p.s. hello from lviv :)
