This may be more than you need, here's the code for the class I use:
public class ControlColorAnimator
{
private const int INTERVAL = 100;
private readonly decimal _alphaIncrement;
private readonly decimal _blueIncrement;
private readonly Color _endColor;
private readonly decimal _greenIncrement;
private readonly int _iterations;
private readonly decimal _redIncrement;
private readonly Color _startColor;
private decimal _currentAlpha;
private decimal _currentBlueValue;
private decimal _currentGreenValue;
private decimal _currentRedValue;
private Timer _timer;
public ControlColorAnimator(TimeSpan duration, Color startColor, Color endColor)
{
_startColor = startColor;
_endColor = endColor;
resetColor();
_iterations = duration.Milliseconds / INTERVAL;
_alphaIncrement = ((decimal) startColor.A - endColor.A) / _iterations;
_redIncrement = ((decimal) startColor.R - endColor.R) / _iterations;
_greenIncrement = ((decimal) startColor.G - endColor.G) / _iterations;
_blueIncrement = ((decimal) startColor.B - endColor.B) / _iterations;
}
public Color CurrentColor
{
get
{
int alpha = Convert.ToInt32(_currentAlpha);
int red = Convert.ToInt32(_currentRedValue);
int green = Convert.ToInt32(_currentGreenValue);
int blue = Convert.ToInt32(_currentBlueValue);
return Color.FromArgb(alpha, red, green, blue);
}
}
public event EventHandler<DataEventArgs<Color>> ColorChanged;
public void Go()
{
disposeOfTheTimer();
OnColorChanged(_startColor);
resetColor();
int currentIteration = 0;
_timer = new Timer(delegate
{
if (currentIteration++ >= _iterations)
{
Stop();
return;
}
_currentAlpha -= _alphaIncrement;
_currentRedValue -= _redIncrement;
_currentGreenValue -= _greenIncrement;
_currentBlueValue -= _blueIncrement;
OnColorChanged(CurrentColor);
}, null, TimeSpan.FromMilliseconds(INTERVAL), TimeSpan.FromMilliseconds(INTERVAL));
}
public void Stop()
{
disposeOfTheTimer();
OnColorChanged(_endColor);
}
protected virtual void OnColorChanged(Color color)
{
if (ColorChanged == null) return;
ColorChanged(this, color);
}
private void disposeOfTheTimer()
{
Timer timer = _timer;
_timer = null;
if (timer != null) timer.Dispose();
}
private void resetColor()
{
_currentAlpha = _startColor.A;
_currentRedValue = _startColor.R;
_currentGreenValue = _startColor.G;
_currentBlueValue = _startColor.B;
}
}
This uses DataEventArgs<T>
(shown below)
/// <summary>
/// Generic implementation of <see cref="EventArgs"/> that allows for a data element to be passed.
/// </summary>
/// <typeparam name="T">The type of data to contain.</typeparam>
[DebuggerDisplay("{Data}")]
public class DataEventArgs<T> : EventArgs
{
private T _data;
/// <summary>
/// Constructs a <see cref="DataEventArgs{T}"/>.
/// </summary>
/// <param name="data">The data to contain in the <see cref="DataEventArgs{T}"/></param>
[DebuggerHidden]
public DataEventArgs(T data)
{
_data = data;
}
/// <summary>
/// Gets the data for this <see cref="DataEventArgs{T}"/>.
/// </summary>
public virtual T Data
{
[DebuggerHidden]
get { return _data; }
[DebuggerHidden]
protected set { _data = value; }
}
[DebuggerHidden]
public static implicit operator DataEventArgs<T>(T data)
{
return new DataEventArgs<T>(data);
}
[DebuggerHidden]
public static implicit operator T(DataEventArgs<T> e)
{
return e.Data;
}
}
Use in your form like this:
private ControlColorAnimator _animator;
private void runColorLoop()
{
endCurrentAnimation();
startNewAnimation();
}
private void endCurrentAnimation()
{
ControlColorAnimator animator = _animator;
_animator = null;
if (animator != null)
{
animator.ColorChanged -= _animator_ColorChanged;
animator.Stop();
}
}
private void startNewAnimation()
{
_animator = new ControlColorAnimator(TimeSpan.FromSeconds(.6), Color.Yellow, BackColor);
_animator.ColorChanged += _animator_ColorChanged;
_animator.Go();
}
private void _animator_ColorChanged(object sender, DataEventArgs<Color> e)
{
invokeOnFormThread(delegate { setColor(e); });
}
private void setColor(Color color)
{
// code to set color of the controls goes here
}
private void invokeOnFormThread(MethodInvoker method)
{
if (IsHandleCreated)
Invoke(method);
else
method();
}