C# Form Fade In/Fade Out

 

This short tutorial is made to show you how to create a fade in / fade out effect for a form. Since basic Windows Forms doesn’t provide such an option, it must be done manually.

Note: we’ll use timers instead of general repetitive structures to avoid thread blocking

Fade in Effect

To do this, all we have to do is to set the Form’s Opacity to 0. Then, using a Timer we’ll slowly increase opacity. All this code should go in a event handler that is executed when the form loads.

As an example:

Timer t1 = new Timer();

private void Form1_Load(object sender, EventArgs e)
{
            Opacity = 0;      //first the opacity is 0

            t1.Interval = 10;  //we'll increase the opacity every 10ms
            t1.Tick += new EventHandler(fadeIn);  //this calls the function that changes opacity 
            t1.Start(); 
}

void fadeIn(object sender, EventArgs e)
{
            if (Opacity >= 1)  
                t1.Stop();   //this stops the timer if the form is completely displayed
            else
                Opacity += 0.05;
}

Fade Out Effect

This works the same way as the fade in effect: we’ll use a Timer that lowers the Opacity, that is started when the form is closing. The code should be added in the form-closing event handler.

private void main_FormClosing(object sender, FormClosingEventArgs e)
{
      e.Cancel = true;    //cancel the event so the form won't be closed

      t1.Tick += new EventHandler(fadeOut);  //this calls the fade out function
      t1.Start();

      if (Opacity == 0)  //if the form is completly transparent
          e.Cancel = false;   //resume the event - the program can be closed

}

void fadeOut(object sender, EventArgs e)
{
      if (Opacity <= 0)     //check if opacity is 0
      {
          t1.Stop();    //if it is, we stop the timer
          Close();   //and we try to close the form
      }
      else
          Opacity -= 0.05;
}

Believe it or not, that’s all, however pay attention to the events so you won’t assign 2 event handlers to the same event.