VB.NET help with drawing
- Thread starter Bluemike
- Start date
Teacher doesn't know? 
. What you want to do is load the image into a picture box. Capture the onClick method of the picture box so when a user clicks on the picture the co-ordinates the click occured at are added to a list. Finally everytime the mouse is clicked pass the list of points to a function which draws a line between each one using GDI+.
I don't code vb.net but C# so I cn't give you exact code, but It would be better for you to learn it anyway but ill give you some of it in c# to help.
Firstly create a default image to display in a picturebox, this can be replaced by using a string path of the image you want to display.
Next you want to capture the Click event, not sure how you do this in VB.Net so I'll let you figure that one, in C# you simple add picturebox1.Click += new EventHandler(pictureBox1_Click); in the form constructor.
Not tested but should be something like that.
. What you want to do is load the image into a picture box. Capture the onClick method of the picture box so when a user clicks on the picture the co-ordinates the click occured at are added to a list. Finally everytime the mouse is clicked pass the list of points to a function which draws a line between each one using GDI+.I don't code vb.net but C# so I cn't give you exact code, but It would be better for you to learn it anyway but ill give you some of it in c# to help.
Firstly create a default image to display in a picturebox, this can be replaced by using a string path of the image you want to display.
Code:
Bitmap b = new Bitmap(picturebox1.Width,picturebox1.Height);
picturebox1.Image = b;Next you want to capture the Click event, not sure how you do this in VB.Net so I'll let you figure that one, in C# you simple add picturebox1.Click += new EventHandler(pictureBox1_Click); in the form constructor.
Code:
private void pictureBox1_Click(object sender, EventArgs e)
{
Point p = PointToClient(new Point(Cursor.Position.X, Cursor.Position.Y)
p.X -= picturebox.Left;
p.Y -= picturebox.Top;
pointlist.add(p);
if (pointlist.Count > 1) //a line can be drawn
{
//draw a line between the point just clicked (lastpoint) and the point preceeding it
Point lastpoint = pointlist[pontlist.Count-1]
Point secondlastpoint = pointlist[pontlist.Count-2]
Graphics.FromImage(pictureBox1.Image).DrawLine(new Pen(Color.Black), secondlastpoint,lastpoint);
}
}Not tested but should be something like that.
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