How to draw an lines on the picturebox over the image?

Question

0.00/5 (No votes)

See more:

Hi everyone.
How to draw an lines on the PictureBox over the image?

Like this:
https://imgur.com/a/EPMJsa1

Thanks advance.

What I have tried:

using (Graphics g = pictureBox.CreateGraphics())
            {
                g.Clear(Color.Transparent);
                Pen p = new Pen(Color.Red, 2.0f);

                for (int n = 1; n <= 50; n++)
                {
                    g.DrawLine(p, n * (Cursor.Position.X), Cursor.Position.Y - 30.0f, n * (Cursor.Position.X), Cursor.Position.Y + 30.0f);

                }
            }

That not working.

Posted 28-Jun-22 23:04pm

User 15226833

Updated 29-Jun-22 9:33am

Add a Solution

2 solutions

Solution 1

"It's not working" is one of the most useless problem descriptions we get: it tells us absolutely nothing about the problem. We don't know if you get an error message, or the wrong data, or even that that code compiles successfully!
Remember that we can't see your screen, access your HDD, or read your mind - we only get exactly what you type to work with.
So tell us what happens when you run that code, what you expected to happen, how you checked what happened. Help us to help you!

But I'll do what I can...

It depends on what you are trying to do: if you want the lines to be "permanent" than you need to get the Graphics context for the Image that the picturebox contains, draw on that, and then invalidate the PictureBox to force a repaint.

If that isn't what you want, then you probably need to handle the PictureBox.Paint event and draw your lines there.

Posted 28-Jun-22 23:25pm

OriginalGriff

Comments

[no name] 29-Jun-22 5:29am

Thanks. Sorry for useless description. Really, that "Not functioning" means: I not getting any error but it just not showing the lines what I want. And I want to lines be an forever.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Tony Hill · Accepted Answer · 2022-06-29T09:33:00

This might work for you

C#

private void ButtonTest_Click(object sender, EventArgs e)
{
    using (Graphics g = pictureBox.CreateGraphics())
    {
        g.Clear(Color.Transparent);

        float ticksPerSide = 7;   // actually its the number of spaces between ticks
        float tickLength = 20;

        float horzSeperation = pictureBox.Width / ticksPerSide;
        float vertSeperation = pictureBox.Height / ticksPerSide;

        Image image = Image.FromFile("c:\\temp\\image.jpg");

        g.DrawImage(image, new RectangleF(0, 0, pictureBox.Width, pictureBox.Height));

        Pen p = new Pen(Color.Red, 2.0f);

        for (int n = 0; n <= ticksPerSide; n++)
        {
            // Draw the ticks on the top of the picture box
            g.DrawLine(p, n * horzSeperation, 0, n * horzSeperation, tickLength);

            // Draw the ticks on the bottom of the picture box
            g.DrawLine(p, n * horzSeperation, pictureBox.Height, n * horzSeperation, pictureBox.Height - tickLength);

            //Draw the ticks on the left of the picturebox
            g.DrawLine(p, 0, n * vertSeperation, tickLength, n * vertSeperation);

            //Draw the ticks on the right of the picture box
            g.DrawLine(p, pictureBox.Width - tickLength, n * vertSeperation, pictureBox.Width, n * vertSeperation);
        }

        // Draw vertical cross hair line
        g.DrawLine(p, pictureBox.Width / 2, 0, pictureBox.Width / 2, pictureBox.Height);

        // Draw horizontal cross hair line
        g.DrawLine(p, 0, pictureBox.Height / 2, pictureBox.Width, pictureBox.Height / 2);
    }
}