Question

Can someone help about create a winform animation like in Win7 Calculator when you hover mouse over button, currently i use bunch of image then looping it in backgroundworker, but i think its wrong, this is my code:

this occur when mouse enter,

private void bgTurnOn_DoWork(object sender, DoWorkEventArgs e)
{
    Label labelSender = (Label)e.Argument;
    int ii = labelSender.ImageIndex;
    for (int i = ii + 4; i <= 11; i++)
    {
        if (labelSender.AllowDrop)
        {
            labelSender.ImageIndex = i;
            Thread.Sleep(40);
        }
    }
}

and this when mouse leave

private void bgTurnOff_DoWork(object sender, DoWorkEventArgs e)
{
    Label labelSender = (Label)e.Argument;
    int ii = labelSender.ImageIndex;
    for (int i = ii; i >= 0; i--)
    {
        if (!labelSender.AllowDrop)
        {
            labelSender.ImageIndex = i;
            Thread.Sleep(80);
        }
    }
}

note: I just use AllowDrop so I do not bother to declare new variable, i have 42 button, so i think i need more efficient solution.

Answer 1

It seems that you want a glow effect, so you can use the next idea:

• Make an OpacityPictureBox : PictureBox which supports opacity (in levels of 1-100 or double 0-1). See this for more information.
• Add two public const int values of MaxOpacity and MinOpacity to the OpacityPictureBox class, for easy and safe range checks from the outside. The values might be 0, 100 or 0, 1, or something else, depending on your implementation of opacity.
• Make an AnimatedPictureBox : UserControl which holds 1 PictureBox named pbNormal and 1 OpacityPictureBox named opbHover, both Dock = DockStyle.Fill, and one timer named timer. Make sure that pbNormal is below opbHover.
• Have three public properties:
  • Normal of type Image which delegates into pbNormal.Image
  • Hover of type Image which delegates into opbHover.Image
  • AnimationInterval of type int which delgates into timer.Interval
• In the constructor of the AnimatedPictureBox, after calling InitializeComponents, do opbHover.Opacity = 0;. You can also do this.Cursor = Cursors.Hand; if you want the cursor to change into a hand when hovering over it.
• Have a private members: _animationDirection of type int, which will be -1 or 1.
• Have a private method that starts an animation in a given direction:

Code:

private void Animate(int animationDirection)
{
    this._animationDirection = animationDirection;
    this.timer.Start();
}

• Override OnMouseEnter and OnMouseLeave:

Code:

 protected override void OnMouseEnter(EventArgs e)
 {
     this.Animate(1);
     base.OnMouseEnter(e);
 }

 protected override void OnMouseLeave(EventArgs e)
 {
     this.Animate(-1);
     base.OnMouseEnter(e);
 }

• Listen to timer.Tick event and with this:

Code:

private void timer_Tick(object sender, EventArgs e)
{
    var hoverOpacity = this.opbHover.Opacity + this._animationDirection;

    if (hoverOpacity < OpacityPictureBox.MinOpacity ||
        hoverOpacity > OpacityPictureBox.MaxOpacity)
    {
        this.timer.Stop();
        return;
    }

    this.opbHover.Opacity = hoverOpacity;
}