public static void GradientRect(Graphics g, Rectangle r, int steps, GradientOptions o)
{
using (SolidBrush b = new SolidBrush(Color.WhiteSmoke))
{
for (int i = 0; i < steps; i++)
{
float xratio = (float)i / steps;
int x0 = (int)(r.Left + r.Width * xratio);
int x1 = (int)(r.Left + r.Width * (float)(i + 1) / steps) - x0;
for (int j = 0; j < steps; j++)
{
float yratio = (float)j / steps;
int y0 = (int)(r.Top + r.Height * yratio);
int y1 = (int)(r.Top + r.Height * (float)(j + 1) / steps) - y0;
Color upper = Colors.Interpolate(o.LeftTop, o.RightTop, xratio);
Color lower = Colors.Interpolate(o.LeftBottom, o.RightBottom, xratio);
Color final = Colors.Interpolate(upper, lower, yratio);
b.Color = final;
g.FillRectangle(b, x0, y0, x1, y1);
}
}
}
}
public GradientOptions GetColors()
{
GradientOptions result = new GradientOptions();
result.LeftBottom = ColorBottomLeft.BackColor;
result.LeftTop = ColorTopLeft.BackColor;
result.RightBottom = ColorBottomRight.BackColor;
result.RightTop = ColorTopRight.BackColor;
return(result);
}
public static void CreateImage(string fileName, GradientOptions colors)
{
var bounds = System.Windows.Forms.Screen.PrimaryScreen.Bounds;
Bitmap b = new Bitmap(bounds.Width, bounds.Height);
Graphics g = Graphics.FromImage(b);
Algorithms.GradientRect(
g,
new Rectangle(0, 0, bounds.Width, bounds.Height),
colors);
b.Save(fileName, System.Drawing.Imaging.ImageFormat.Bmp);
}
private void ButtonSetAsWallpaper_Click(object sender, EventArgs e)
{
GradientOptions options = GetColors();
// on Windows XP, only bmp seems to be updated correctly
// on Vista and above, this could be .jpg (gradients are best compressed with .jpg)
string fileName = Path.Combine(
Environment.GetFolderPath(Environment.SpecialFolder.MyPictures),
@"GradientWallpaper.bmp");
Algorithms.CreateImage(fileName, options);
API.SetDesktopWallpaper(fileName);
}
public static void GradientRect(Graphics g, Rectangle r, GradientOptions o)
{
GradientRect(g, r, 256, o);
}