但是图的边缘呈锯齿状，请问如何抗锯齿。谢谢
public static void CreateControlRegion(Control control, Bitmap bitmap)
{
//判断是否存在控件和位图
if (control == null || bitmap == null)
return;
//设置控件大小为位图大小
control.Width = bitmap.Width;
control.Height = bitmap.Height;
//当控件是form时
if (control is Form)
{
//强制转换为FORM
Form form = (Form)control;
//当FORM的边界FormBorderStyle不为NONE时，应将FORM的大小设置成比位图大小稍大一点
form.Width = control.Width;
form.Height = control.Height;
//没有边界
form.FormBorderStyle = FormBorderStyle.None;
//将位图设置成窗体背景图片
form.BackgroundImage = bitmap;
//计算位图中不透明部分的边界
GraphicsPath graphicsPath = CalculateControlGraphicsPath(bitmap);
//应用新的区域
form.Region = new Region(graphicsPath);
}
//当控件是button时
else if (control is Button)
{
//强制转换为 button
Button button = (Button)control;
//不显示button text
button.Text = "";
//改变 cursor的style
button.Cursor = Cursors.Hand;
//设置button的背景图片
button.BackgroundImage = bitmap;
//计算位图中不透明部分的边界
GraphicsPath graphicsPath = CalculateControlGraphicsPath(bitmap);
//应用新的区域
button.Region = new Region(graphicsPath);
}
}
/// <summary>
/// Calculate the graphics path that representing the figure in the bitmap
/// excluding the transparent color which is the top left pixel.
/// //计算位图中不透明部分的边界
/// </summary>
/// <param name="bitmap">The Bitmap object to calculate our graphics path from</param>
/// <returns>Calculated graphics path</returns>
private static GraphicsPath CalculateControlGraphicsPath(Bitmap bitmap)
{
//创建 GraphicsPath
GraphicsPath graphicsPath = new GraphicsPath();
//使用左上角的一点的颜色作为我们透明色
Color colorTransparent = bitmap.GetPixel(1, 1);
//第一个找到点的X
int colOpaquePixel = 0;
// 偏历所有行（Y方向）
for (int row = 0; row < bitmap.Height; row++)
{
//重设
colOpaquePixel = 0;
//偏历所有列（X方向）
for (int col = 0; col < bitmap.Width; col++)
{
//如果是不需要透明处理的点则标记，然后继续偏历
if (bitmap.GetPixel(col, row) != colorTransparent)
{
//记录当前
colOpaquePixel = col;
//建立新变量来记录当前点
int colNext = col;
///从找到的不透明点开始，继续寻找不透明点,一直到找到或则达到图片宽度
for (colNext = colOpaquePixel; colNext < bitmap.Width; colNext++)
if (bitmap.GetPixel(colNext, row) == colorTransparent)
break;
//将不透明点加到graphics path
graphicsPath.AddRectangle(new Rectangle(colOpaquePixel, row, colNext - colOpaquePixel, 1));
col = colNext;
}
}
}
return graphicsPath;
}
