效果：
private void Form1_Load(object sender, EventArgs e)
{
string file =System.IO.Path.Combine(Environment.CurrentDirectory, @"11.jpg");
try
{
Image i = new Bitmap(file);
pbO.Image = i; pbD1.Image = WayOne(file);
pbD2.Image = WayTwo(file); pbS1.Image = WaySOne(file);
pbS2.Image = WaySTwo(file); }
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
private Bitmap WayOne(string file)
{
using (Image i = new Bitmap(file))
{
Bitmap b = new Bitmap(i.Width, i.Height);
using (Graphics g = Graphics.FromImage(b))
{
g.FillEllipse(new TextureBrush(i), , , i.Width, i.Height);
}
return b;
}
}
private Bitmap WayTwo(string file)
{
using (Image i = new Bitmap(file))
{
Bitmap b = new Bitmap(i.Width, i.Height);
using (Graphics g = Graphics.FromImage(b))
{
g.DrawImage(i, , , b.Width, b.Height);
int r = Math.Min(b.Width, b.Height) / ;
PointF c = new PointF(b.Width / 2.0F, b.Height / 2.0F);
for (int h = ; h < b.Height; h++)
for (int w = ; w < b.Width; w++)
if ((int)Math.Pow(r, ) < ((int)Math.Pow(w * 1.0 - c.X, ) + (int)Math.Pow(h * 1.0 - c.Y, )))
{
b.SetPixel(w, h, Color.Transparent);
}
}
return b;
}
} private Bitmap WaySOne(string file)
{
using (Image i = new Bitmap(file))
{
Bitmap b = new Bitmap(i.Width, i.Height);
using (Graphics g = Graphics.FromImage(b))
{
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
using (System.Drawing.Drawing2D.GraphicsPath p = new System.Drawing.Drawing2D.GraphicsPath(System.Drawing.Drawing2D.FillMode.Alternate))
{
p.AddEllipse(, , i.Width, i.Height);
g.FillPath(new TextureBrush(i), p);
}
//g.FillEllipse(new TextureBrush(i), 0, 0, i.Width, i.Height);
}
return b;
}
}
private Bitmap WaySTwo(string file)
{
using (Image i = new Bitmap(file))
{
Bitmap b = new Bitmap(i.Width, i.Height);
using (Graphics g = Graphics.FromImage(b))
{
g.DrawImage(i, , , b.Width, b.Height);
int r = Math.Min(b.Width, b.Height) / ;
PointF c = new PointF(b.Width / 2.0F, b.Height / 2.0F);
for (int h = ; h < b.Height; h++)
for (int w = ; w < b.Width; w++)
if ((int)Math.Pow(r, ) < ((int)Math.Pow(w * 1.0 - c.X, ) + (int)Math.Pow(h * 1.0 - c.Y, )))
{
b.SetPixel(w, h, Color.Transparent);
}
//画背景色圆
using (Pen p = new Pen(System.Drawing.SystemColors.Control))
g.DrawEllipse(p, , , b.Width, b.Height);
}
return b;
}
}