C#

private void textBox1_MouseEnter(object sender, EventArgs e)
        {
            Graphics g = textBox1.CreateGraphics();
            g.DrawRectangle(new Pen(Brushes.Red, 3), new Rectangle(0, 0, textBox1.Width - 5, textBox1.Height - 5));
        }

        private void textBox1_MouseLeave(object sender, EventArgs e)
        {
            Graphics g = textBox1.CreateGraphics();
            g.DrawRectangle(new Pen(Brushes.White, 3), new Rectangle(0, 0, textBox1.Width - 5, textBox1.Height - 5));            
        }

mav.northwind wrote:

you don't dispose of the Graphics object

mav.northwind wrote:

drawing to the textbox in this way is only visible as long as the textbox isn't redrawn.

Regards

Nader Elshehabi wrote:

Well, last time I checked my GC wasn't on vacation! My graphics objects are local variables, they will be disposable once the call to the handler is over

using (Graphics g = textBox.CreateGraphics())
{
}

Nader Elshehabi wrote:

Unfortunately, no! This is not a webpage where the user may click refresh, and almost all the causes of paint are mouse involved. Once the mouse is out of the box, it doesn't matter!!

mav.northwind wrote:

you're not calling Dispose()

mav.northwind wrote:

just move another window over the textbox (or part of it) and you'll see what I mean.

Regards

Nader Elshehabi wrote:

How could you do that without moving the mouse out of the textbox first?

private bool DrawBox = false;

private void textBox1_MouseEnter(object sender, EventArgs e)
{
    Drawbox = true;
}

private void textBox1_MouseLeave(object sender, EventArgs e)
{
    Drawbox = false;
}

//now draw the Box according to input focus

private void textBox1_Enter(object sender, EventArgs e)
{
    Drawbox = true;
}

private void textBox1_Leave(object sender, EventArgs e)
{
    Drawbox = false;
}

private void textBox1_Paint(object sender, EventArgs e)
{
    Graphics g = textBox1.CreateGraphics();
    if(DrawBox)    
        g.DrawRectangle(new Pen(Brushes.Red, 3), new Rectangle(0, 0, textBox1.Width - 5, textBox1.Height - 5));
    else
        g.DrawRectangle(new Pen(Brushes.White, 3), new Rectangle(0, 0, textBox1.Width - 5, textBox1.Height - 5));
    g.Dispose();
}

Regards

shyagam wrote:

Is it wrong to invoke an event?
What's wrong with my parameters?

Ed.Poore wrote:

Care to provide some more details?

Ed.Poore wrote:

As of how to accomplish this, have you ever tried Google?

shyagam wrote:

I sometimes get an "Parameter is invalid" exception

shyagam wrote:

never happend in my previous projects.