加载图像，通过单击按钮在其上绘制形状，通过鼠标在其上绘制线条

Question

I want to load an image (for example in a panel) and messure the edges of the picture_by using the functions I have_ and draw the lines of the edges on the image by clicking a button.After that, I want to draw extra lines on the same image by using mouse.I also want to be able to erase the painted lines by mouse without erasing the image later. I don't know which function I should use in every case.One way may be that I set the backgroundImage of the panel with my image and use the paint function to draw exta lines _drawn by mouse.if I use this method, then which function should I use to draw lines of edges_drawn by clicking button? Is there a better way? Please guide me .Thanks in advance.

Answer 1

see below code ..hope this will help you

Point startPoint = new Point();
bool dragging = false;

int testOne = 30;
int testTwo = 30;

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
{
    if (dragging)
    {
        int diffX = (pictureBox1.PointToClient(e.Location).X - startPoint.X);
        int diffY = (pictureBox1.PointToClient(e.Location).Y - startPoint.Y);

        label9.Text = diffX.ToString();   //Works, shows desired result
        label10.Text = diffY.ToString();  //also works fine

        testOne = (testOne + diffX); //Issue here
        testTwo = (testTwo + diffY); //and here

        label11.Text = (testOne).ToString(); //Unexpected results output
        label12.Text = (testTwo).ToString(); 
    }
}

private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
{
    if (!dragging) //Incase the mouse down was repeating, it's not
    {
        startPoint = pictureBox1.PointToClient(e.Location);
        dragging = true;
    }
}

private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
    if (dragging)
        dragging = false;
}