Question

I am developing a Windows application in which I want to display a pop-up form. I’d like this form to open the same way as a lightbox window does (like when using a jQuery lightbox plugin, for example). How would I go about this?

Answer 1

To answer the revised question

i want some smooth fadein animation for popup form

On your dialog form set the Opacity equal to a low number like 10%

Add a System.Windows.Form.Timer. Set its Enabled property to true and its Interval property to 50

For the timer tick event handler write this.

    private void timer1_Tick(object sender, EventArgs e)
    {
        if (this.Opacity == 1 )
        {
            this.timer1.Enabled = false;
            return;
        }

        this.Opacity+=.1;

    }

You can try different values of the stepping (this.Opacity+=.1;) and the timer’s interval to find the the timing you like best.