/// <summary>
/// Fills <see cref="Rectangle"/> with Colors that smoothly fades from one side to the other.
/// </summary>
/// <param name="rectangle"><see cref="Rectangle"/> to fill</param>
/// <param name="startColor">Start Color for the fill</param>
/// <param name="endColor">End Color for the fill</param>
/// <param name="direction">Direction of the fade from Start to End</param>
/// <remarks>
/// This method only supports linear gradient fills
/// </remarks>
/// <exception cref="PlatformNotSupportedException">
/// Thrown when this method is used in a device older than Pocket PC 2003
/// </exception>
public void GradientFill(Rectangle rectangle, Color startColor,
Color endColor, GradientFillDirection direction)
{
var tva = new TRIVERTEX[2];
tva[0] = new TRIVERTEX(rectangle.Right, rectangle.Bottom, endColor);
tva[1] = new TRIVERTEX(rectangle.X, rectangle.Y, startColor);
var gra = new[] { new GRADIENT_RECT(0, 1) };
var hdc = Surface.GetHdc();
try
{
if (Environment.OSVersion.Platform == PlatformID.WinCE)
{
NativeMethods.GradientFill(
hdc,
tva,
(uint)tva.Length,
gra,
(uint)gra.Length,
(uint)direction);
}
else
{
NativeMethods.GdiGradientFill(
hdc,
tva,
(uint)tva.Length,
gra,
(uint)gra.Length,
(uint)direction);
}
}
catch (MissingMethodException)
{
throw new PlatformNotSupportedException("Gradient Fill is not supported in this platform");
}
finally
{
Surface.ReleaseHdc(hdc);
}
}
public static void GradientFill(this Graphics g, Rectangle rec, Color fromColor, Color toColor, GradientFillDirection direction, Blend blend = null)
{
int angle = 0;
switch (direction)
{
case GradientFillDirection.Horizontal:
angle = 0;
break;
case GradientFillDirection.Vertical:
angle = 90;
break;
}
g.GradientFillAtAngle(rec, fromColor, toColor, angle, blend);
}
